1 LITHUANIAN UNIVERSITY OF HEALTH SCIENCE
FACULTY OF MEDICINE
Department of Obstetrics and Gynecology
The Impact of Eating Disorders on the
Course and Outcome of Pregnancy and
Delivery – a literature review
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Contents
Contents ... 2 Summary ... 3 Acknowledgements ... 4 Conflicts of interest ... 5Permission issued by the Ethics Committee ... 6
Abbrevations ... 7
Introduction... 8
Aim and Objectives ... 10
Literature Review... 11
Research Methodology and Methods... 12
Results ... 14
Fertility, conception and unplanned pregnancy ... 15
Course of pregnancy ... 16
Course and outcome of pregnancy and delivery ... 21
Long-term outcomes of offspring of mothers with ED ... 26
Discussion ... 30
Conclusion ... 34
Practical recommendations ... 35
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Summary
Author Henrike Ewerbeck
Supervisor Dr. Gintana Ramoniene
Research Title The impact of eating disorders on the course and outcome of pregnancy and delivery Aim To determine the impact eating disorders may or may not have on the course and outcome of
pregnancy and delivery.
Objectives
1) To assess and evaluate current publications about fertility and the outcome of pregnancy and delivery in relation to eating disorders.
2) To assess and evaluate the impact of eating disorders on course and outcome of pregnancy and delivery across eating disorder subtypes.
3) To assess and evaluate the course of eating disorders and disordered eating during pregnancy.
4) To assess and evaluate the long-term outcomes of children born to a mother with past or current eating disorder.
Methodology In this systematic literature review different databases (PubMed, PsycInfo, EuropePMC
etc) were searched using the keywords "pregnancy", "pregnancy outcomes", "eating disorders", "anorexia nervosa", "bulimia nervosa" and "binge eating disorder". The search engine Google Scholar was also used.
Results Eating Disorders including Anorexia Nervosa, Bulimia Nervosa and Binge Eating Disorder
are mental disorders which are highly prevelant worldwide, especially in women. About 8% of women of reproductive age are affected by any form of eating disorder. During the review it became evident that all of the included eating disorder subtypes (Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder and Eating Disorder Not Otherwise Specified) were related to some degree to adverse outcomes of pregnancy and delivery. The complications of Anorexia Nervosa (AN) were commonly attributed to the inability to maintain an adequate weight and included an increase in unplanned pregnancy, excessive gestational weight gain, small for gestational age infants and low birth weight. Among others, Bulimia Nervosa (BN) was associated with a greater incidence of fertility treatment, increased risk of induced abortions and increased rate of miscarriages. Binge Eating Disorder (BED) was frequently related to being overweight and obese and the subsequent complications. All eating disorders were related to a higher incidence of psychological comorbidities and a higher perception of distress about the pregnancy and subsequent changes in body weight and shape. Pregnancy seems to be a window of opportunity for women suffering of BN or AN who showed a significant incidence of remission. However, pregnancy seems to be a window of vulnerability for the onset, relapse and shifting to BED. Offspring born to mothers related to ED were more likely to display long-term complications related to cognitive and functional development, neurobehavioral regulation and childhood wheezing.
Conclusion Most of the searched studies suggest that eating disorders have a significant impact on
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Acknowledgements
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Conflicts of interest
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Permission issued by the Ethics Committee
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Abbrevations
BMI Body Mass Index
ED Eating Disorder
AN Anorexia Nervosa
BN Bulimia Nervosa BED Binge Eating Disorder
EDNOS Eating Disorder Not Otherwise Specified SGA Small for Gestational Age
LGA Large for Gestational Age LBW Low Birth Weigh
WHO World Health Organisation
DSM Diagnostic and Statistical Manual of Mental Disorders EDE-Q Eating Disorder Examination Questionnaire
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Introduction
Eating disorders including anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED) and eating disorder not otherwise specified (EDNOS) are mental disorders which are highly prevalent worldwide, especially in women. The incidence of eating disorders even increased during the last decade significantly [1].
It is widely known that eating disorders are in general associated with a lot of psychological and physiological complications. Beside the increased risk of psychological problems like depression and suicidal behaviour, it may also lead to several physiological impairments. In case of anorexia nervosa those complications arise directly from extreme weight loss and malnutrition. Hormone secretion may be reduced and lead to amenorrhea. Complications of bulimia nervosa are related to self -induced vomiting and laxative abuse which can lead to dehydration and electrolyte disbalance [5]. Binge eating disorder may cause complications related to high body weight and excessive eating. Therefore, the complications may be exhibiting clinical signs of several gastrointestinal symptoms, metabolic disturbances and diabetes mellitus [3]. The long-term complications can be severe and even fatal, with anorexia nervosa being associated with the highest mortality rate among eating disorders [6]. During pregnancy the body experiences a lot of natural changes that are necessary to ensure a safe pregnancy course and delivery, but about 8% of women of reproductive age are affected by an eating disorder [7]. This is of great interest for society since several perinatal outcomes have been
associated with maternal eating disorders, like prematurity, small- and large for gestational-age, increased incidence of caesarean section, intrauterine growth restriction and perinatal mortality [8]. Accumulating evidence also suggests that anorexia nervosa and bulimia nervosa are associated with a younger age at the time of birth and an increased risk for unplanned pregnancy [9], which accounts as a risk factor itself.
Diagnosing an eating disorders may prove to be a challenge since a lot of women are reluctant to disclose their illness. Further, the signs of disordered eating may be mistaken for classic signs of pregnancy, like morning sickness, changes in eating habits, repulsive behaviour towards food, food cravings and aversions and weight gain or weight loss [10].
However, to ensure proper treatment and prevention of long-term complications it is crucial to diagnose the disease as early as possible.
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Aim and Objectives
Aim This Master Thesis aims toward the idea of a general overview of recent publications and a
summary of the current discussion that is present about the topic of eating disorders in relation to pregnancy and subsequent complications and adverse outcomes.
Objectives
1) To assess and evaluate current publications about fertility and the outcome of pregnancy and delivery in relation to eating disorders.
2) To assess and evaluate the impact of eating disorders on course and outcome of pregnancy and delivery across eating disorder subtypes.
3) To assess and evaluate the course of eating disorders and disordered eating during pregnancy
4) To assess and evaluate the long-term outcomes of children born to a mother with past or current eating disorder
Hypothesis
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Literature Review
Eating Disorders are highly prevalent in today’s society and represent a significant proportion of mental disorders worldwide, especially in women. During the past decade, the incidence was on a rise and the trend aims towards a further increase [1]. Subtypes of ED include Anorexia Nervosa (AN), Bulimia Nervosa (BN), Binge Eating Disorder (BED) and Eating Disorder Not Otherwise Specified (EDNOS).
There are different approaches of defining eating disorders. According to the World Health Organisation, Anorexia Nervosa is defined as a disorder characterized by deliberate weight loss, induced and sustained by the patient. It is associated with a dread of fatness and flabbiness of body image and persists as an intrusive overvalued idea. Therefore, the patient imposes a low weight threshold on themselves. Bulimia Nervosa is defined as a syndrome characterized by repeating cycles of overeating and excessive preoccupation with the control of body weight, leading to a pattern of overeating followed by any form of purging, for example excessive exercise, fasting, abuse of laxative or self-induced vomiting [2].
Binge eating disorder has only recently been recognized as a distinct eating disorder (2013). It is characterized by consumption of large amounts of food in a short period of time, that is untypical for most people, and a sense of loss of control over eating during these episodes. Unlike anorexia nervosa and bulimia nervosa, there is no purging behaviour to undo the act and it is usually related to high body weight [4].
Eating disorder not otherwise specified (EDNOS) is classified as an eating disorder, that does not meet the criteria for Anorexia Nervosa or Bulimia nervosa. Those individuals either express subthreshold symptoms, atypical behaviour or do not meet any characterisations at all. [2]
Another approach to defining eating disorders is according to the Diagnostic and Statistical Manual of Mental Disorders (DSM) by the American Psychiatric Association.
According to the DSM-5 criteria, Anorexia Nervosa is diagnosed if the person displays persistent restriction of energy intake, which leads to a significantly low body weight, an intense fear of gaining weight or becoming fat or persistent behaviour that interferes with weight gain, as well as a
disturbance in the way the individual experience one's body weight or shape.
Bulimia Nervosa is defined as recurrent episodes of binge eating, which are characterised by an amount of food that is larger than most people would eat, consumed in a discrete period of time and a sense of control loss during this period. Further, the individual must display inappropriate
compensatory actions to prevent weight gain, like self-induced vomiting, abuse of laxatives or diuretics, fasting, or excessive exercise. Those episodes of binging and purging must occur at least once a week for three months.
According to the DSM-5 criteria, Binge Eating Disorder is characterized by recurrent episodes of binge eating, related to severe distress, eating until feeling uncomfortably full, eating much more rapidly than normal, eating despite not feeling hungry, feeling of embarrassment and disgust. Binge eating is not associated with compensatory behaviour and must occur at least once a week for three months. [3]
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Research Methodology and Methods
Search procedure
In advance to the search procedure, a search protocol was formulated to agree on inclusion and exclusion criteria.
A comprehensive search of the current literature on pregnancy course and outcome in relation to eating disorders was performed using Databases PubMed, Europepmc.org and PsycInfo.
The following search terms were used: "pregnancy", "eating disorders", "anorexia nervosa", "bulimia nervosa", "binge eating disorder", "delivery", "course", "pregnancy outcomes". These terms were then used in combination and correlation with each other. The search was adjusted for studies being less than 10 years old and for accessibility of full texts. The search was conducted in the library of the University of Health Science of Kaunas in order to grant unlimited access.
After the removal of duplicates, 89 studies on PubMed, 3 on Europepmc.org and 0 on PsycInfo were included and the titles and abstracts were screened for suitability. Of those, 46 studies were deemed adequate for a thorough evaluation of the full text.
The full text analysis excluded a further of 19 studies, and a total of 27 studies was included in the final sample.
For more details see Flowchart 1.
Inclusion and exclusion criteria
The studies were initially screened by title, then by abstract and finally by full text. Studies were included if they comprised outcomes of pregnancy and child birth that might be a consequence of an eating disorder, the short and long term impact of eating disorders on mother and child, the course of the eating disorders in relation to pregnancy and the relationship between specific eating disorders with respective adverse outcomes. Studies investigating the impact of complications caused by anorexia nervosa, bulimia nervosa and binge eating disorder were included if they were also related to fertility, pregnancy or delivery outcomes. More than 70% of the included studies did not exceed the release date of 10 years.
Those studies not providing a link between both conditions were excluded, as well as studies
approaching the topic only briefly or in a manner that provided broad, superficial information. Studies with small sample sizes were only included if the scientific evidence was sufficient. One study was excluded due to limited access.
Data analysis
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Results
The results of this literature review are grouped according to the following criteria: concerns about fertility, conception and unplanned pregnancy; the course of pregnancy; course and outcome of pregnancy and delivery; and outcomes of offspring of mothers with eating disorders. In total, 27 studies were identified and included in this review.
Approach to represent studies and their results
This systemic review includes 27 studies analyzing poor pregnancy course and outcomes and long-term outcomes in women with a history of ED. 9 studies are prospective [11, 14, 17, 18, 23, 26, 33, 34, 36,] and 6 are retrospective [12, 21, 25, 28, 37], one displays a mixed character of retrospective and prospective design [20], one is a validation study of previous findings of the same group [22], one study is termed exploratory study [19]. The sample size in the studies varied from 63 to 117 875. The studies were published in 2009 – 2018.
The majority of the studies included in this review are long-term and cohort studies. Further, most of them work with questionnaires and/or assessment scales according to their respective aim. 3 studies deal with fertility problems and unplanned pregnancy [11, 12, 13], 9 studies evaluate the course of eating disorders and disordered eating during pregnancy as well as the course of pregnancy in terms of weight gain and pregnancy related complications [14-22], 10 studies evaluate the details about the course and outcomes of pregnancy and delivery [23-32], 5 studies analyze the outcomes of offspring born to mothers with a current or past history of eating disorder [33-37]. In this review, the results will be presented according to the previously introduced scheme. Obviously, the themes of the studies cannot be apprehended exclusively and will overlap. To provide a quick overview, the studies are represented in table 1-4 seen below, outlining the most important information, i.e., the author and year of publication, sample size, main parameters and methods of approach. The Questionnaires used in the respective study can be found in the Annex of this literature review.
MoBa – Den Norske Mor & Barn-undersokelsen (Norwegian Mother and Child Cohort Study)
8 of the studies that were relevant for this topic were associated with the MoBa study [13, 15, 16, 19, 22, 24, 26, 36]. This is an ongoing long-term prospective cohort study including 110 000 pregnant Norwegian women and their children, enrolled between 1999 and 2008 and was conducted by Magnus et al. [38]. Women in their 17th week of gestation, who were registered in any gynecological
clinic, were invited to participate. Those who agreed filled questionnaires at five set points of time during their pregnancy and in the postpartum period, i.e., 17th and 30th week of gestation, as well as 6,
18 and 36 months postpartum. The questionnaires included questions about the mother’s health, diet and nutrition and the health, diet and nutrition of their respective child. A total of 100 349 births and 86 007 mothers was recorded in the time period of 1999 to 2008 [39].
Other relevant birth cohorts
Further cohort studies related to this literature review were the Avon Longitudinal Study of Parents and Children (ALSPAC), which is a large cohort study based in Bristol, United Kingdom. Participants were recruited between April 1991 and December 1992 and initially included more than 14 000 pregnant women and 14 000 births, resulting in 13 988 live children, which have been under continuous follow up over the next decades [40].
Another study involved is the Nord-Trondelag Health Study (HUNT), based in Norway. It is a
longitudinal population health study with an ongoing dataset since 1984, which includes information on almost 120 000 people [41].
14 months after delivery, respectively. The questionnaires included themes like outcomes, diet and health status. The study also performs regular follow ups on the children enrolled in the cohort [42]. Further, Generation R study is mentioned in relation to this topic. It is a population-based prospective cohort study, that recruited a total of 9778 mothers delivering between April 2002 and January 2006. The study performed regular follow ups until the age of 10 years for the born children in this time period. Data was collected by questionnaires, interviews, physical and ultrasound examinations and more.
Fertility, conception and unplanned pregnancy
Studies represented in table 1 investigate the impact eating disorders may or may not have on fertility [11, 12], conception time [11] and the mothers’ attitude to the pregnancy [11, 12]. They also evaluate if the pregnancy was planned or not and the related backgrounds [12, 13]. All the studies are large population-based cohort studies, who compared a sample of women with a diagnosis of ED with a healthy control group. The data was recorded via questionnaires or by analyzing birth records. Table 1 represents the most important information about the relevant studies concerning fertility problems, conception and unplanned pregnancy in relation to ED.
Author, Year, Country Sample size Main objectivs Method Easter et al. 2011, United Kingdom [11] N = 14 663 Fertility problems Conception time Attitudes to pregnancy ALSPAC Prospective study Micali et al. 2013, Netherlands [12] N = 6318 Fertility treatment Unplanned pregnancy Attitudes to pregnancy Retrospective longitudinal population-based study Bulik et al. 2010, Norway [13]
N = 62 060 Mothers age at birth Unplanned pregnancy Induced abortion
MoBa
Questionnaires
Table 1.
Fertility treatment Eating disorders are considered a predictor for increased risk of fertility problems
15 A retrospective study conducted by Micali et al. based on the longitudinal population-based birth cohort of Generation R examined data of 6328 eligible cases of whom 170 reported a history or current active form of AN, 265 reported a history or current active form of BN and 130 stated a history or current active form of AN and BN. They found that women reporting lifetime BN were four times more likely to have received induced ovulation and two times more likely to have received fertility treatment. They found that this did not account for women suffering from lifetime AN or AN+BN. [12] A study by Linna et al. mentioned in table 3 investigating statistical data about numbers of children, births, miscarriages and induced abortions of women with ED, examined additionally the data on infertility treatments in their cohort from the Medical Birth Register. They did not find statistically significant differences across the analyzed groups. [31]
Pasternak et al. conducted a population-based retrospective study to compare singleton deliveries of women with and without ED. A total of 117 875 occurred during the time the study was performed, 122 of those were from women suffering of an ED. Those two samples were compared to each other. ED were classified according to the DSM-IV criteria. Women suffering of ED were significantly
associated with a higher rates of fertility treatment. [27]
Intentional pregnancy The findings concerning the question, whether the pregnancy was planned or
not were mixed across studies. Easter et al. found that the women in their sample were more likely to report their current pregnancy as intentional. An exception were women with lifetime AN, who were less likely to have intentional pregnancies and had higher odds of unplanned pregnancies. [11] On the contrary, Micali et al. found, that the women across all ED groups were more likely to report unplanned pregnancy. However, women with AN reported the highest prevalence of unplanned pregnancy [12], which is in line with the findings of Easter et al. [11].
A study by Bulik et al., based on self-report and questionnaires as part of the MoBa study, reported that women with AN were significantly more likely of having an unplanned pregnancy [13].
These findings indicate that women with ED can and do become pregnant, even though the prevalence of amenorrhea may be increased across ED groups [43].
Time taken to conceive Only one study analyzed the question about the time it took women with ED
to conceive their current pregnancy. In general, women in the ED group did not seem to be more likely to take longer than 12 months to conceive than the healthy control group, nevertheless, Easter et al. found some evidence, that women affected by lifetime AN with a cross over to BN were more likely to need more than 6 months to conceive. [11]
Attitude towards pregnancy In general, all studies reported an association with a tendency to have
negative or mixed feelings about discovering their pregnancy across ED groups. This tendency seemed to be highest in women suffering of past or current AN [11,12]. Easter et al. reported that the negative feelings diminished during the ongoing pregnancy, though a trend of negativity remained in the ED group compared to the general population. Additionally, women with lifetime AN and AN+BN had increased odds of experiencing motherhood as a personal sacrifice. [11]
Course of pregnancy
Studies represented in Table 2 examine the course of eating disorders and disordered eating during pregnancy, as well as possible pregnancy complications related to eating disorders or disordered eating. Pregnancy related complications or circumstances are excessive or inadequate gestational weight gain [15, 16, 19, 20], weight retention postpartum [15], miscarriage and induced abortion [17]. Other studies evaluated eating disorder symptoms during pregnancy [14, 18-22] on different
16 therefore based on a large population-based cohort [15, 16, 19, 22]. Three studies are determined as prospective studies and used different types of questionnaires to record data and analysis of records of birth and health institutions [14, 17, 18, 20, 21].
Author, Year, Country Sample size Main objectives Method Nunes et al. 2014, Brazil [14] N = 712 ED symptoms during pregnancy and postpartum Prospective cohort study Zerwas et al. 2014, Norway [15]
N = 65 321 Maternal weight gain and retention
MoBa
Siega-Riz et al. 2011, Norway [16]
N = 35 148 Maternal weight gain MoBa
O'Brien et al. 2017, USA [17] N = 47 759 Predictors of ED Parity Pregnancy related complications Miscarriage Induced abortion Preterm birth LBW Descriptive analysis of a prospective Sister cohort study Chan et al. 2018, China [18] N = 1470 Disordered eating Apgar score Birth weight Prospective longitudinal study Eating Attitudes Test 26 (EAT-26)
Knoph Berg et al. 2011, Norway [19]
N = 45 644 BED during pregnancy MoBa
Exploratory study Coker et al. 2013,
Australia [20]
N = 178 Gestational weight gain ED status Prospective and retrospective study QOLED questionnaire Easter et al. 2013, UK [21] N = 739 ED symptoms before
and during pregnancy
Retrospective study Eating disorder diagnostic scale (EDDS) Watson et al. 2013, Norway [22] N = 77 267 Course of ED during pregnancy MoBa Validation study Table 2.
Course of eating disorder during pregnancy The course of the eating disorder during pregnancy
17 A prospective cohort study conducted by Nunes et al. used the eating disorder examination
questionnaire (EDE-Q) to assess a sample of 712 women between their 16th and 36th week of
gestation, during 28 days of pregestational period and at 4th to 5th month postpartum, respectively.
This questionnaire investigates the eating behavior during the past 4 weeks and deals with general symptoms of disordered eating, shape and weight concerns and obsessive behavior about food. Nunes et al. focused mainly on the changes of eating disorder symptoms during the subsequent time periods. They found that the number of women reporting shape and weight concerns diminished during pregnancy when compared to pre-pregnancy but increased in the postpartum period
significantly. Further, they found that ED behaviors were less common during pregnancy and until 5 months postpartum. Though women in this study appeared to express weight and shape concerns, they did not actively participate in disruptive behaviors characteristic for eating disorders. [14] An exploratory study performed by Knoph Berg et al. used data provided by the MoBa study to evaluate factors that are associated with BED in pregnancy. To achieve this, they used a
questionnaire completed by 45 644 women at 18 weeks of gestation that were designed according to the DSM criteria. 1887 women of the sample met the criteria for BED. Of those, 49.3% reported new onset of BED during the course of the pregnancy. The other 50.7% reported symptoms of BED before pregnancy. The majority of those reporting BED before pregnancy continued to meet the criteria for BED during pregnancy, while 38.8% of them showed remission during pregnancy. [19]
Coker et al. conducted a retrospective questionnaire concerning the time before pregnancy and prospectively for each trimester during pregnancy and at 3, 6 and 12 months postpartum. Changes in BMI and quality of life related to ED were assessed and evaluated in 178 pregnant women. The questionnaire included questions about height and weight, and eating behavior, feelings about ED, psychological matters, the effect of eating, exercise and body weight on daily feeling and the medical status. Coker et al. found that 19 women in their sample showed symptoms of a current ED and 13 women had a previous history of ED. They found that there was a general improvement in symptoms of ED and quality of life during pregnancy, especially in the second and third trimester. Nevertheless, the quality of life related to ED remained low before, throughout and after pregnancy. [20]
Easter et al. investigated the status of ED in a sample of women in early pregnancy during their first routine antenatal appointment. Participants were asked to fill in the Eating Disorder Diagnostic Scale which is a diagnostic tool using the DSM-IV criteria to assess AN, BN and BED. The questionnaire included questions concerning ED symptoms and behaviors during pregnancy and 6 and 12 months before pregnancy. It was completed by 739 women in total of whom 56 reported having an ED during pregnancy and 62 stated to have an ED before pregnancy. They found that women with a current ED or a history of ED were more likely to have weight and shape concern both before and during
pregnancy. Women meeting the criteria for AN before pregnancy continued to display criteria during pregnancy. One case of BN was found in the sample before pregnancy but was not displayed any longer during pregnancy. Further, there was a total of seven new onset cases of BED during
pregnancy. A significant number of women who met the criteria for EDNOS-P before pregnancy did not display symptoms during pregnancy. Nevertheless, there were also 15 new cases of EDNOS-P during pregnancy. Also, compensatory behavior such as self-induced vomiting was more common during pregnancy compared to pre-pregnancy. [21]
18 suffering of BED showed the highest risk of continuation and incidence in both the training and the validation sample. Women with BN and EDNOS-P most commonly displayed remission and/or partial remission throughout both samples. In general ED was relatively common in the sample analyzed by Watson et al. occurring in 1 in every 21 women and most of the cases were cases of BED. It was detected that the sample previously examined by the group [Bulik et al. 2007] was valid, since the new findings did not differ significantly from their findings. In conclusion it was found that pregnancy was a window of vulnerability for new onset of BED and in some rare cases of BN and EDNOS-P. [22]
Disordered eating during pregnancy In a prospective longitudinal study conducted by Chan et al.
the researches focused on the nature of disordered eating in pregnancy. A sample of 1470 women was assessed at five points from the first trimester to six months postpartum using the Eating Attitudes Test-26 in which the participants were asked to indicate on a scale from 1 (never) to 6 (always) if certain statements applied to them. This study is unique among the others included in this review, since it does not analyze eating disorders according to the WHO or DSM criteria, and instead solely relayed on the results of their questionnaires. Chan et al. found that women who showed disordered eating behaviors before pregnancy tend to improve during pregnancy, but that there is a worsening of symptoms of disordered eating when comparing pregnancy to postpartum period. They also detected that infants born large for gestational age, low birth weight or having a 1-min Apgar Score were associated with higher levels of disordered eating. [18]
Maternal weight gain and retention Several studies hypothesized that maternal weight gain and
retention may differ in ED when compared to the general population or a healthy control group and further, that maternal weight gain and retention may differ across ED subgroups.
A prospective cohort study found that women who displayed eating disorder symptoms were more likely to gain excessively during pregnancy. Further, women who were associated with binge eating in the postpartum period had a significant higher mean weight retention. [14]
Another study conducted by Zerwas et al. compared the gestational and postpartum weight trajectories in mothers with and without ED in the large population-based cohort MoBa. The data collection was based on five of the six self-report questionnaires provided by MoBa. It showed that women across all ED subgroups gained weight more quickly during pregnancy, and lost he weight more quickly in the postpartum period in comparison to the women without ED. Nevertheless, the different subgroups must be kept in account. Women with AN were found to have a lower mean BMI pre-pregnancy and may therefore benefit from increased weight gain during pregnancy to ensure a safe gestation, while women with BN fell in the normal weight BMI range and women with BED in the overweight category. Zerwas et al. found that the weight changes during pregnancy in BN, BED and EDNOS-P were significantly higher than in women without ED. [15]
Siega-Riz et al. also collected data from the population-based MoBa cohort to evaluate the amount of weight women with ED gained during pregnancy at various gestational ages. The data collection was based on questionnaires 1, 3 and 4. After applying several exclusion criteria 35 148 participants were included in their analysis. Excessive weight gain was defined according to the IOM guidelines. Siega-Riz et al. found that women with BN and BED gained significantly more weight on average than the women in the healthy control group. It was detected that the majority of women across all ED
subtypes (AN, BN, EDNOS-P and BED) gained excessively [16]. Both Zerwas et al. and Siega-Riz et al came to the conclusion that excessive weight gain was beneficial for women with AN since they started at a lower pre-pregnancy weight, while excessive weight gain was harmful for women with BED because they tend to start pregnancy at a higher weight [15,16]. Women with BN had a similar weight as the healthy control group, but they gained more weight during pregnancy and were therefore at higher risk of gaining excessively [16].
Coker et al. found in their retrospective study that women with ED or a history of ED weight significantly less than women without ED before, during and after pregnancy. Nevertheless, the
19 control. Women reporting ED gained significantly less weight than the minimum recommended
amount. [20]
A prospective study by Nunes et al. analyzed the impact of binge eating behavior during pregnancy on the outcomes of birth and also examined the gestational weight gain. In a sample of 712 women reporting binge eating before their pregnancy, data about weight and height, eating behavior, gestational weight gain, pregnancy complications and obstetric and neonatal outcomes were collected. Eating behaviors were assessed using the Eating Disorder Examination Questionnaire (EDE-Q). The results were compared to a healthy control group. They found that women who reported binge eating during pregnancy gained significantly more weight during pregnancy than the healthy control group. [23]
A study conducted by Bulik et al. used the data provided by MoBa to investigate the relationship between ED and pregnancy related complications, gestational weight gain and birth outcomes and was based on first and fourth questionnaire which were handed to the women participating in the study. A total of 35 929 was included in the research and analyzed thoroughly. Women with a history of AN were significantly younger and had a lower BMI than the healthy control group. Further, BMI in women with BED was significantly higher than in the control group. Bulik et al. found that women in all ED groups except for EDNOS-P gained more weight during pregnancy than mothers in the healthy control group. [24]
Micali et al. performed a study using data provided by Generation R which is a prospective general population cohort based in the Netherlands in a large multi-ethic sample. Participants were recruited if they delivered between April 2002 and January 2006. A total of 5256 women were identified for the study. Of those, 438 reported having any form of ED either in the past year or at any point of life. 1002 women were classified as having another form of mental disorder. The remaining 3816 women were used as healthy control group. Data was provided by local hospital registers or via questionnaires. It was detected that women with AN had a lower BMI pre-pregnancy than he healthy control group, but a faster weight gain during pregnancy. In general, women with a lifetime history of AN gained more weight when compared to the healthy control. Further, women suffering of lifetime BN had a higher BMI, but gained weight slower than the healthy control group. [28]
Miscarriage A prospective study conducted by O’Brien et al. analyzed data provided by the Sister
Study cohort. This cohort included 50 884 women who had a sister with breast cancer between the years 2003 and 2009. Beneath others, this study used dietary questionnaires. According to those, 967 participants were identified who reported having an ED. They found that women with a history of ED were associated with a history of recognized miscarriage. [17]
In a population-based study by Eagles et al. it was found that the rate of miscarriage did not significantly differ from the healthy control group [29].
Linna et al. conducted a study analyzing the effect of ED on reproductive health outcomes. For that purpose, 2257 women treated in a ED clinic between 1995 and 2010 were identified and compared to a healthy control sample of 9082 women which was obtained from the Central Population Register. AN, BN and their atypical forms were classified according to the ICD-10 criteria, while BED was classified by the DSM-IV criteria. Data was analyzed at two points. The rates of pregnancies, childbirths, abortions and miscarriages were compared initially when the event took place first and then throughout the entire study period. Contrary to previous findings, Linna et al. found that women with a diagnosis of AN displayed lower rates of miscarriage when compared to other ED types included in the study, though still showed a trend towards increased risk of miscarriage when compared to the healthy control. Further, they found that women with a diagnosis of BED had the highest rates of miscarriages when compared to the healthy control group and to the other ED subtypes analyzed in the study. Women with BN were found to not have significant different rates of miscarriages than the control group. [31]
Induced abortion A prospective study conducted by Bulik et al. mentioned previously in relation to
20 to undergo an induced abortion, which appeared to be specific for BN [17]. In contrast, Eagles et al. did not find a significant difference in incidence of pregnancy termination when comparing a sample of women with AN to a healthy control group [29].
A study by Linna et al. found that women with a diagnosis of AN had lower rates of induced abortion when compared to a healthy control group. On the other hand, women with BN had slightly elevated rates of induced abortion. Further, women with a diagnosis of BED did not show a significant
difference in rates of induced abortion compared to the healthy control. [31]
Course and outcome of pregnancy and delivery
Table 3 summarizes studies related to the course and outcome of pregnancy and delivery. Evaluated Parameters include birth weight [23, 24, 26-30, 32], birth length [26, 32], prematurity [23, 27-30], small for gestational age (SGA) and large for gestational age (LGA) [23-26, 28, 30, 32], gestational weight gain [24, 28], stages of labor [26, 30], mode of delivery including induction of labor [29, 30],
instrumental delivery [26, 28, 29] and caesarian section [23-30], Apgar score [25, 30], intrauterine growth restriction (IUGR) [27, 29], antepartum hemorrhage [29], perinatal death, neonatal
resuscitation, premature contractions [30], suspected fetal distress [28], head and abdominal circumference, gestational age [32]. One study evaluated numbers of children, births, induced abortions and miscarriages in relation to eating disorders [31].
SGA was defined as a birth weight below the 10th percentile, and LGA as a birth weight above the 90th
percentile in most of the studies mentioned below. The study conducted by Eik-Nes et al. defined SGA as a birth weight below the 3rd percentile and LGA as a birth weight above the 97th percentile
[25]. Preterm birth was defined as gestation length of less than 37 weeks. Postmature birth was defined as gestation length of more than 42 weeks.
Pregnancy related complications were categorized as pregnancy induced hypertension [25, 28-30], maternal diabetes mellitus [26, 27, 28], bleeding during pregnancy [26], hospitalization during pregnancy for more than 24 hours during the first two trimesters of pregnancy [28], miscarriage [29] and anemia during pregnancy [30].
Two studies were related to the population-based cohort of the MoBa study [24, 26]. One was based on the HUNT study [25]. Studies mentioned in table 3 gathered their data by self-report,
questionnaires and by analyzing birth records, hospital registers or databanks.
Author and year Sample size Main objectives Methods Nunes et al. 2012, Brazil [23] N = 697 Birth weight Prematurity Caesarian delivery SGA / LGA Prospective cohort study Questionnaire Birth records Bulik et al. 2009, Norway [24] N = 35 929 Pre-pregnancy BMI Gestational weight gain SGA / LGA
Caesarian delivery
21 Eik-Nes et al. 2018, Norway [25] N = 44 189 Pregnancy related complications Perinatal death SGA / LGA Caesarian delivery Apgar score HUNT study Retrospective longitudinal study Watson et al. 2017, Norway [26] N = 70 881 Prolonged labor Caesarian delivery Birth weight / length SGA / LGA MoBa Prospective study Pasternak et al. 2012, Israel [27] N = 117 875 Fertility treatment Intrauterine growth restriction Prematurity Caesarian delivery Retrospective study Micali et al. 2012, UK [28]
N = 5256 Gestational weight gain Birth weight Pregnancy related complications Postnatal complications Prematurity SGA / LGA Retrospective longitudinal study Eagles et al. 2012, UK [29] N = 804 Birth weight Intrauterine growth restriction Antepartum hemorrhage
Aberdeen Maternal and Neonatal Databank
Linna et al. 2014, Finland [30]
N = 11 285 Birth weight
22 Premature contractions Resuscitation of neonate Maternal hypertension Linna et al. 2013, Finland [31] N = 11 285 Number of: - children - pregnancies - childbirths - induced abortions - miscarriages - infertility treatment Analysis of register-based information from the eating disorder clinic of Helsinki University Central Hospital and Central Population Register Micali et al. 2015, UK [32] N = 83 826 Birth weight/length Head circumference Abdominal circumference Gestational age SGA / LGA Longitudinal population-based cohort Table 3.
Pregnancy related complications O’Brien et al. reported in their analysis of the Sister Study cohort
that having a history of ED was positively associated with bleeding, nausea and vomiting during pregnancy. Further, O’Brien et al. did not find an association between ED and pregnancy related hypertensive disorders or gestational diabetes. [17]
A study by Watson et al. used the data provided by the MoBa study to link three generations to detect a relationship between ED and adverse outcomes of pregnancy, delivery and neonatal outcomes, as well as the subsequent risk for ED in the adult offspring. The three generations were linked through birth register records and survey data reported by the mothers who participated in the MoBa study. Watson et al. used version 8 of the quality assured data files which were released for research in 2015. The sample included maternal grandmothers and mothers of the MoBa study with their
offspring. Two sets of population were evaluated and compared according to questionnaires provided by MoBa. One dataset included women with an ED during pregnancy while the other dataset was about women with a lifetime ED. The first dataset concerning women with an ED during pregnancy included 70 881 grandmothers, mothers and children. The second dataset concerning a lifetime history of ED included 52 348 grandmothers, mothers and children. ED were classified according to DSM-V criteria. They found that women with a lifetime history of BN or BED were related to a higher risk of diabetes during pregnancy. A lifetime history of BED was further associated with a higher risk of pre-eclampsia. [26]
23 Sinna et al. conducted a study analyzing women with a lifetime history of ED and if they were
positively associated with pregnancy, obstetric and perinatal complications. They collected data of 2257 women who were registered and treated in an ED clinic and compared them to a large sample of healthy women in a control group which was taken from the general population. Information was taken from the Medical Birth Register for all singleton births in a time period from 1995 to 2010. The final sample included 11 280 women. AN and BN were classified according to the ICD-10 criteria, while BED was classified according to the DMS-IV criteria. They found that women with BN and BED had a higher number of total prenatal care visits compared with the healthy control group. Further, it was found that across all subgroups of ED, women visited the hospital more frequently than the healthy control group. It was detected that women with AN had a higher risk of anemia during pregnancy and women with BED had a higher risk of maternal hypertension than the control group. Concerning other obstetric complications, the group did not find significant differences in rates of asphyxia and breech presentation. [30]
Birth weight (SGA, LGA) and Prematurity A study by O’Brien et al. analyzing the Sister study
cohort found that women with ED were more likely to give birth to a low birth weight term infant. Further they found that women with a history of ED were associated with preterm birth [17]. On the other hand, Nunes et al. found in their study performed on a population of 712 women that binge eating during pregnancy was not associated with SGA, LGA and prematurity [23].
Bulik et al. found in their study based on the data provided by MoBa that women with BED displayed a significantly lower risk of having a SGA infant and were related to significantly higher risk for having a LGA infant than the healthy control group. [24]
Eik-Nes et al. analyzed two sources for the collection of their data: the population-based HUNT study was used as a healthy referent sample, while patients from the patient registry were used for the exposed sample. The latter were obtained from a local hospital patient register in a specialized ED unit. Women who have had at least one birth record in the medical birth registry were included. A total of 272 women with a history of ED and their births (n=532) were selected for the exposed sample, in the healthy referent sample 19 049 women and their births (n=43 651) were included. ED were defined according to the WHO (ICD) and DSM criteria. It was found that women with a lifetime history of AN and those with a history of purging behavior were more likely to give birth to a SGA infant. Eik-Nes et al. did not find a significant difference in respect to preterm birth when comparing the healthy sample to the exposed sample. [25]
Watson et al. found that women with AN during pregnancy were significantly associated with having babies with smaller birth length and were less likely to have infants with large birth length. Mothers with BED during pregnancy displayed a significantly higher risk of having LGA infants. [26]
Pastenak et al. found in their retrospective study that women with ED had significantly higher rates of preterm deliveries, as well as a higher risk of delivering a term low birth weight infant. Intrauterine growth restriction appeared to be increased in women with ED when compared to the healthy control group. [27]
24 babies with a lower birth weight relative to the control group. However, women with a lifetime history of BED were more likely to give birth to babies with a higher birth weight than in the control group. It was found that rates of LGA were increased in the BED group, while rate of SGA were increased in the AN group. Also, the risk of delivering prematurely was increased in women with AN. [30]
Micali et al. conducted a prospective population-based cohort study investigating size at birth and preterm birth in women with a lifetime history of ED. Data was obtained from the Danish National Birth Cohort which is a longitudinal cohort of more than 100 000 pregnancies recorded in Denmark
between 1996 and 2002. Additional data was obtained by telephone interviews at 16th – 17th week of
gestation. A total of 83 826 women was included in the analysis. During the telephone interviews women were asked if they ever suffered from an ED. This study is unique in that, they described a crossover of AN to BN or BN to AN as a separate category in their study and termed it AN+BN. Further, AN was categorized into recent or past categories to determine if the disease was active. In case of a BMI of less than 18.5 women were termed as “active AN”, while women with a BMI of more than 18.5 they were termed as “past AN”. It was found that women with a lifetime history of AN and a lifetime history of AN+BN were more likely to deliver babies with a lower birth weight and length as well as a lower head and abdominal circumference than the babies in the healthy control group. Further, it was found that women with lifetime history of AN and AN+BN were more likely to deliver a SGA baby. These findings did also account for both active and past AN. Micali et al. did not find a significant difference in rates of prematurity when comparing the exposed sample to the healthy control group. Nevertheless, there was some evidence found that women with an active form of AN were more likely to have a preterm birth when compared to the control group. [32]
Stages of Labor In a study by Watson et al. it was detected that women with AN during pregnancy
were less likely to have prolonged labor. Further they found that having a lifetime history of BED was associated with prolonged labor. [26]
Linna et al. found in their large population- and birth register-based cohort that women with a lifetime history of AN or BN were associated with a higher risk of premature contraction when compared to a healthy control group. Further, they found that women with a lifetime history of AN had a shorter first stage of labor and women with a lifetime history of BED had a longer first and second stage of labor in relation to the unexposed group. [30]
Mode of delivery A study conducted by Bulik et al. found that women suffering from BED were more
likely to have a cesarean section. Further, they found that women with BN had significantly higher rates for assistance at vaginal breech position and were related to a greater risk of induction of birth. Both women with AN and BED were found to have a greater probability of receiving an epidural. [24] Eik-Nes et al. found that women with BN and purging behavior were more likely to have a caesarian section when compared to the healthy control group [25].
In a unique study linking three generations in the MoBa cohort Watson et al. found that mothers with AN during pregnancy were associated with a higher risk of caesarian section. Further it was found that mothers with BN during pregnancy were associated with a higher risk of induced delivery and mothers with BED during pregnancy were more likely to have a caesarian section and induced delivery. Similar results were found for women with a lifetime history of BED, who showed an association with caesarian section and induced delivery. [26]
Pastenak et al. found that women with ED were more likely to have a caesarian section when compared to healthy control group [27].
On the other hand, a study performed by Linna et al. compared a large group of women suffering of ED with a healthy control group and did not find a significant difference in rates of induction of labor, instrumental delivery, epidural anesthesia, and elective or non-elective caesarian section [30].
Apgar score A few studies evaluated the Apgar score in their considerations. Eik-Nes et al. detected
25 Linna et al. found that women with a lifetime history of BN displayed increased odds of delivering an infant with a very low Apgar score at 1 minute when compared to the unexposed control group [30].
Perinatal death, neonatal resuscitation A study conducted by Linna et al. found that women with a
lifetime history of AN had a significantly increased risk of perinatal death, and that women with a lifetime history of BN had higher odds of delivering a neonate that required resuscitation right after birth [30]
Number of children, births A study by Pastenak et al. found that women with ED were more likely to
be nulliparous [27]. Eagles et al. detected that women with AN had slightly fewer children compared to their healthy control group [29]. A large cohort study by Sinna et al. found that women with a lifetime history of AN and BED did not have less children than the healthy control group, though women displaying a lifetime history of BN had a lower number of previous births when compared to the healthy control group [30]. These findings were supported by another study conducted by Linna et al. who found that women with a diagnosis of ED were more likely to be childless than the healthy control. This was especially evident in women with AN, whose pregnancy rate was significantly lower compared to the unexposed group, though rates were in general low across all ED subgroups
examined in the study [31].
Long-term outcomes of offspring of mothers with ED
Table 4 displays studies that examined the long term outcomes and complications of offspring who were born to mothers with a past or current ED. Parameters included in this studies were
neurobehavioral and cognitive development of infants born to mothers with ED [33,34], head growth of the offspring [34], the development of childhood wheezing in relation to maternal ED [35],
peculiarities of weight-for-length trajectories [36] and the relationship between neonatal Intensive Care Unit (ICU) admission and maternal disordered eating behavior during pregnancy [37]. One study was based on the population-based cohort study MoBa [36], while another was related to the data of the NINFEA cohort [35]. Others were defined as prospective longitudinal study and longitudinal cohort study, which used questionnaires and self-reports as sources of their data collection.
Study Sample Main objectives Method
Barona et al. 2017, USA [33] N = 63 Neurobehavioral and cognitive development of infants born to mothers with ED Prospective longitudinal study Koubaa et al. 2013, Sweden [34]
26 Czecg-Szczapa et al.
2015, Poland [37]
N = 326 Relationship between
neonatal intensive care unit admission and disordered eating attitudes during pregnancy in mothers Retrospective case control study Table 4.
Neurobehavioral and cognitive development The question whether women suffering of a past or
active form of ED is influencing the neurobehavioral and cognitive development of the offspring was addressed in a prospective longitudinal study by Barona et al. They used data gathered in the nutrition and stress in pregnancy (NEST-p) study, which recruited pregnant women in their first or second trimester. ED were classified according to the DSM-IV criteria and evaluated by self-report using the EDE-Q. A total of 137 participants were recruited from antenatal care and special ED services. 37 of those were suffering of an active ED, 39 were classified as having a past ED, the remaining 61 women formed the healthy control sample. To determine the newborns development the Brazelton Neonatal Behavioral Assessment Scale (NBAS, Brazelton and Nugent, 1995) was used. This scale includes items evaluating the newborns orientation, motor development, autonomous state, reflexes and habits. The babies of mothers included in this study were assessed at two different points in time: 8 days after birth and one year after birth. The second evaluation was performed by using the Bayley Scales of Infant and Toddler Development (Bayley, 2006). It examines the child’s cognitive, language and motor development.
The researches detected that women with a history of ED were more likely to have babies whose motor organization and autonomic stability was worse than of those in the healthy control group. Deterioration in autonomic stability was indicated by difficulties in regulating functions of the autonomic system like breathing or temperature. Further, children born to a mother with ED had higher odds of language and motor development difficulties. Those differences were associated with having an active form of ED. Babies of women with a history of ED in the past were also more likely to show the previously mentioned difficulties, but the difference was statistically not significant. It was found that babies of women with past ED were more likely to have lower scores on the assessment scale used one year after birth, but not at the first point of assessment 8 days after birth, while
mothers with an active ED gave birth to babies who showed neurobehavioral dysregulation right after delivery. [33]
A longitudinal cohort study conducted by Koubaa et al. investigated the relationship between a maternal history of ED and the head growth and neurocognitive development of their offspring. For that purpose, they recruited 112 children, of whom 47 were born to mothers with a history of ED. The remaining 65 formed the healthy control group. ED was diagnosed according to the DSM-IV criteria. Data on the children’s growth was collected at 3, 6, 12, 18 months and 3, 4 and 5 years of age. Information about the head circumference of the children was gathered from medical records from birth up to 18 months postpartum. The group also investigated the maternal adjustment to
motherhood at 3 months postpartum by using a questionnaire. When the children were 5 years old they were further assessed for their neurocognitive development by using another questionnaire filled in by the mothers. The questions included items like motor skills, memory, language skills, planning and organizing and social skills. It was found that women with a history of ED delivered babies with a lower mean birth weight than the control group. This difference did not persist at 3 months of age and at 5 years of age the height of the children was not significant different across all groups.
Nevertheless, it was found that women with BN had children with a significant lower height at the age of 4 when compared to the healthy control group. The babies BMI at birth was lower in women with a history of ED when compared to the healthy control, this difference also did not persist at older age. Mothers suffering of ED delivered babies with a smaller head circumference, which persisted throughout the entire study period. The evaluation of the questionnaires showed that women with a history of ED indicated a lower neurocognitive function of their child. The head circumference
27 lower the children scored on neurocognitive functioning. These findings were especially evident in matters of language and social skills. [34]
Childhood wheezing In an effort to analyze the findings from the NINFEA birth cohort study, Popovic
et al. evaluated the impact maternal ED may or may not have on early childhood wheezing [35]. Early childhood wheezing is characterized by airway obstruction, which is most commonly caused by bronchiolitis and asthma, but it can also be idiopathic or related to anatomical abnormalities or
external causes like frequent aspiration, neurologic or muscular dysfunction and more. It also bears a risk itself to develop asthma and can lead to poor quality of life. [44]
Popovic et al. gathered information using questionnaires. At enrollment, a first questionnaire was filled by the mothers at any time during pregnancy, then in a follow up at 6 and 18 months postpartum and when the children were 4, 7 and 10 years old respectively. Childhood wheezing was evaluated by using a separate questionnaire in which mothers were asked if their child had at least one episode of wheezing or whistling between 6 and 18 months of age and further, if a doctor confirmed a diagnosis of wheezing. It was considered if the mother was smoking during pregnancy or at 18 months after delivery. A total of 5150 children was examined in that way. Popovic et al. detected that children of mothers with ED had higher odds of developing childhood wheezing. The risk was even higher when the ED was active during pregnancy. Even for mothers who displayed purging behavior without a diagnosis of ED, the risk was elevated of having a child who developed wheezing at some point between 6 and 18 months of age. The risk was especially considerable in mothers with lifetime BN when compared to the other subgroups and the healthy control. Further, children born to mothers with active AN during pregnancy displayed an increased risk for developing wheezing in comparison to the other subgroups and the healthy control. It must be taken in consideration that women in this study who suffered of any form of ED were more likely to smoke during and after pregnancy, which itself is a risk factor for the development of wheezing in childhood. [35]
Growth and weight-for-length trajectories Perrin et al. conducted a prospective cohort study
investigating if women with ED gave birth to children with lower weight-for-length trajectories in the first year of their life [36]. Growth trajectories in early life are an indicator for chronic diseases later in life, e.g. rapid weight gain in early childhood is associated to being overweight. The physiological standard for weight-for-length trajectories was based on the WHO guidelines [45].
ED were classified according to the DSM-IV criteria. The data included in this study was based on the information provided by the Norwegian MoBa study and the child’s “health card” which is a ongoing record of the measurements and immunization status of the child. 6 and 18 months after birth, mothers were asked to fill in a questionnaire about their offspring’s weight and length at 6 weeks and 3, 6, 8, 12 and 18 months, respectively. Weight-for-length trajectories were recorded at birth and at 12 months of age. A total of 57 185 mothers were included in this study. It was found that women with AN and BN had infants with lower weight-for-length trajectories, which means that their babies were smaller at birth and remained smaller at the 12 months follow-up when compared to the healthy control group. The contrary accounted for women with EDNOS-P and BED, who delivered infants with greater weight-for-length trajectories in comparison to the healthy control group. Within 4 months after birth, children of women with ED experienced a higher growth rate and caught up to the healthy control group. Further, women with BN and BED had higher weight-for-length at birth, but lower growth rate over the following 12 months when compared to the healthy control group. In general, mothers with a history of ED gave birth to babies that were significantly associated with lower weight-for-length trajectories than the healthy control group. [36]
Neonatal ICU admission Czech-Szczapa et al. conducted a retrospective case control study in order
28 associated with eating disorders or disordered eating behavior. Women in the study sample displayed a tendency of gaining significantly less weight during pregnancy than the control group. Low
pregnancy weight gain was significantly associated with preterm birth. Women in the study sample reported fear of gaining weight during pregnancy. Further, women in the study sample were
29
Discussion
This systemic literature review offers an insight into the current publications about the impact eating disorders may have on the course and outcome of pregnancy and delivery and the long-term consequences it may have for the offspring born to a mother with an eating disorder. After thorough screening of scientific databases 27 studies were identified and included. The results were grouped according to the following scheme: Fertility, conception and unplanned pregnancy; course of
pregnancy: course and outcome of pregnancy and delivery; long-term outcomes of offspring of mothers with ED. The sample sizes varied immensely across studies, ranging from 63 to over 100 000 participants. Further, studies were placed in several different countries across the globe: Norway, the Netherlands, the United Kingdom, Brazil, USA, Australia, China, Israel, Finland, Sweden, Italy and Poland. A general bias accounting for all included studies is indicated by the fact, that women with a history of ED tend to display mental and physiologic co-morbidities that were only considered by some of the studies, but not all of them. Further, people suffering of ED tend to be more reluctant about their disorder and avoid talking about it or keep parts of it to themselves.
This risk of bias accounts for most of the included studies because they relied heavily on self-report [11, 12, 14-26, 28, 32, 34-37].
Fertility, conception and unplanned pregnancy
Across several studies, eating disorders were found to be a risk factor for fertility problems. Women with ED were more likely to have received help to conceive their pregnancy [11]. Lifetime BN was significantly associated with higher odds of induced ovulation or fertility treatment [12]. This was supported by another study, finding that women with ED were associated with higher rates of fertility treatment [27]. On the contrary, one large medical register-based study did not find a statistically significant difference between women with and without ED [31]. This discrepancy may be explained by the difference in sample size, as well as the variation in countries. Also, the reliance on self-report [11, 12] bears a risk of validation bias and measurement error.
Women with ED were more likely to report unplanned pregnancy [11, 12, 13] and were more likely to have taken more than 6 months to conceive their current pregnancy [11]. Further, women reporting a relation to ED prior or during their pregnancy indicated negative or mixed feelings upon discovering their pregnancy [11, 12]. Those feelings diminished during the ongoing pregnancy but remained relatively high, as well as a feeling of personal sacrifice across AN and AN+BN subgroups [11].
Course of pregnancy
Pregnancy appeared to be a window of opportunity for the remission of EDNOS-P and BN, but a window of vulnerability for BED. It was detected that the number of women reporting weight and shape concerns diminished during pregnancy when compared to pre-pregnancy [14, 18, 21] but increased during the postpartum period [14, 18]. Further, a general improvement of symptoms of disturbed eating behavior like purging was detected during pregnancy [14, 18, 20]. The opposite was found in another study, detecting that compensatory behavior was more common during pregnancy compared to pre-pregnancy [21]. Women with EDNOS-P were associated with recovery during pregnancy [21]. On the contrary, women with BED persisted showing symptoms throughout pregnancy [19] while others developed new onset of BED during pregnancy and women with AN continued meeting the criteria for AN throughout their pregnancy [21].
30 The question if maternal weight gain differs in women with ED was examined by several studies included in this systemic literature review. It was found that women with a history of ED were more likely to gain excessively during their pregnancy [14, 15, 16, 23, 24, 28] and were also more likely to retain the weight postpartum [14]. On the contrary, another study found that women reporting ED gained significantly less weight than the minimum recommended amount [20]. This discrepancy may be explained by the sample size, which was significantly smaller in the latter study and included only 17 women with an ED in a total cohort of 178 women compared to the other mentioned studies with much bigger samples varying from 697 to 65 321 participants. In conclusion, most studies agreed that women related to any form of ED were more likely to gain significantly. Further, it was found that for women with AN, who tended to start their pregnancy at a lower BMI than the other ED groups or the healthy control group, the excessive weight gain was beneficial for both the mothers and the
offspring’s health. On the other hand, excessive weight gain appeared to be harmful for women with BED or BN because they had a higher or normal BMI pre-pregnancy.
Across studies investigating the relation between ED and abortion, the findings were inconclusive. One study found that women with a history of ED were associated with miscarriage [17], while another stuy detected that there was no significant difference between ED group and healthy control group in their sample [29]. Women with BED displayed the highest rates of miscarriage across ED subtypes and in comparison with the healthy control, while women with AN had slightly decreased rates of miscarriage when compared to the other ED subtypes, but still showed a trend of increased risk when compared to the healthy group. Women with BN did not have a significant different rate in miscarriages than the control [31].
Women with BN were more likely to undergo induced abortion [17, 31], while women related to BED did not show significant difference in rates of induced abortion [31]. Findings for women with a history of AN were contradicting across studies. One prospective study found that women with AN showed significantly higher rates of abortion [13], while another stated that the rates of induced abortion were lower among women with AN when compared to the healthy control sample [29].
Course and outcome of pregnancy and delivery
Pregnancy in women with ED was associated with several complications.
Women with ED were associated with bleeding, nausea and vomiting during pregnancy [17]. Lifetime history of BN or BED was related to a higher risk of gestational diabetes and BED was associated with a higher risk of pre-eclampsia [26] and hypertension during pregnancy [30]. The rate of
hospitalization was higher in women with ED [28, 30] and women with AN were more likely to have suspected fetal distress [28] and antepartum hemorrhage [29]. Women with BN and BED had a higher number of prenatal care visits. Women with AN were more likely to have anemia during pregnancy [30].
Women with ED were more likely to have a low birth weight infant at term [17, 27]. Specifically, AN and BN was associated with low birth weight [30, 32]. BED was associated with LGA [24, 26, 30]. On the other hand, women with AN were more likely to deliver SGA infants [25, 30, 32]. ED was also associated with increased risk for intrauterine growth restriction [27] and slow fetal growth in case of AN [30]. Another study found that binge eating during pregnancy was not significantly associated with LGA and SGA [23]. Though binge eating was not determined as ED itself, but as one symptom that did not lead to a diagnosis. Another study investigating ED in general without differentiating between subtypes did not find significant association with ED and SGA [28]. Further, one study detected that AN was not significantly related to low birth weight, but to intrauterine growth restriction [29].
