Results were similar in women with
and without eating disorders.
Reprinted from Eating Disorders Review
January/February Volume 24, Number 1
©2013 Gürze Books
Early clinical studies have suggested that women with eating disorders are at increased risk of perinatal complications and problems during delivery. However, in a large population-based cohort study in The Netherlands, a maternal lifetime history of eating disorders was associated with few adverse perinatal outcomes (BJOG. 2012; 19:1493).
For their multi-center study of gestational weight gain, Dr. Nadia Micali and colleagues used data from the Generation R Study, a population-based prospective cohort study designed to identify early environmental and genetic causes of normal and abnormal growth, development and health from fetal life until young adulthood (Eur J Epidemiol. 2008; 23:801). Women who enrolled prenatally, who had provided complete information on lifetime exposure to an eating disorder, and who had given birth to a live single child were divided into 4 study groups. The study groups were: women with lifetime anorexia nervosa (AN; n=129); women with lifetime bulimia nervosa (BN; n=209); those with a lifetime history of AN and BN (n=1002); and a control group of women with no history of an eating disorder (n=3816).
The researchers noted that there is still much uncertainty about the biological mechanisms that might explain the increased risk of adverse perinatal outcomes in women with eating disorders. The most common explanations include poor weight gain during pregnancy as well as low pre-conception body mass index (BMI, kg/m2). In a prior population-based study in the United Kingdom, the authors showed that low BMI before conception mediated, to a large extent, the risk of women with lifetime AN having lower birth weight babies (J Psychiatry. 2007; 190:255).
Similar incidence of complications with and without eating disorders
Dr. Micali reported that, overall, pregnancy complications affected about 15% of the women and occurred in similar percentages among women with histories of eating disorders and the control group. Gestational diabetes was rare across the entire sample, and affected only 0.8%. Pre-eclampsia, pregnancy-induced hypertension and the HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count), as well as the need for hospitalization during pregnancy occurred in similar numbers of women with histories of eating disorders and controls. There was, however, some evidence that women with AN had 80% higher odds of suspected fetal disorders compared to controls. Women with both AN and BN had increased odds of being hospitalized during pregnancy. Percentages of spontaneous delivery and postnatal complications were comparable across exposure groups before and after adjustment for confounding factors.
The authors reported that mean birth weight was similar across the 4 study groups and comparable in babies of women with lifetime eating disorders, babies of women with other psychiatric disorders, and babies of controls. Maternal AN was associated with a lower weight compared with controls; however, there was a positive interaction between maternal lifetime AN and the term of gestation, corresponding to a 0.07% higher relative increase per week compared with the control group. In contrast, women with lifetime BN had a higher body weight but a lower body weight increase over time compared to control women. There was evidence that women with lifetime AN gained more weight overall compared with unexposed women.
The prevalence of small for gestation age (SGA) infants was low in all groups, between 0.8% and 4%. There was no evidence that women with lifetime eating disorders (or lifetime history of other psychiatric disorders) had increased odds of having SGA babies compared to unexposed women. The frequency of premature births was comparable across all groups, except for a slightly higher percentage among women with AN and BN (7.8% vs. 4.3% in unexposed women).
The role of gestational weight gain
According to the authors, there is still little data about gestational weight gain among women with eating disorders. Earlier clinical studies did not identify differences in gestational weight gain in women with eating disorders and controls. The only large study to investigate gestational weight gain found that women with BN gained more weight at each trimester compared with unexposed women; they were also more likely to gain weight excessively (Institute of Medicine definition) compared with unexposed women (Obstet Gynecol. 1997; 89:865).
Women with lifetime AN gained more weight across pregnancy, whereas women with lifetime BN gained less weight across pregnancy compared with unexposed women. The authors surmised that these patterns of weight gain might be appropriate and protective, considering pre-pregnancy weight across these two groups. The fact that birth weights were comparable with those of babies of controls corroborates this hypothesis, according to the researchers.