A reminder that eating disorders other than AN can be present in pregnant patients.
Pregnancy brings a wide variety of bodily changes and can also trigger symptoms of eating disorders. The connection with AN and concerns about weight gain are perhaps best known but, as a recent study showed, other eating disorders, such as BN and binge eating disorder (BED), are also present during pregnancy and the postpartum period.
Dr. Mantala Milembamane and a team at the Division of Food and Nutritional Sciences, Brescia University College, London, Ontario, Canada, examined the association between lifetime maternal eating disorders, including AN, BN, and BED, with low birth weight (LBW) infants, preterm birth (PTB) infants, small for gestational age (SGA) infants, and large for gestational age (LGA) infants. The study also included data on miscarriages (Can J Diet Practice and Research. 2024.85:53).
After a thorough review, the authors identified 18 studies that met their criteria. The final review included 6 studies on miscarriage, 11 on PTB, 4 on LBW, 9 on SGA, and 4 on LGA infants. The meta-analysis on BED and PTB included 3 studies, involving a combined sample of 42,068 women.
A marked increase in low birth weights
AN was associated with a 74% increase in the prevalence of LBW and a 39% increase in the prevalence of SGA; BN was associated with a 19% increase in the prevalence of PTB; and BED was associated with a 43% increase in the prevalence of LGA. None of the eating disorders was significantly associated with miscarriage.
Earlier studies
Earlier systematic reviews have investigated the association between eating disorders and birth outcomes, and large studies have made important headway into this topic. For example, das Neves et al. found that AN and BN are positively associated with LBW, and BED is associated with higher birth weights and infants who are LGA (J Bras Psiquiatr. 2021. 44:201). Another systematic review found that AN is associated with miscarriage and PTB, and that BN is associated with giving birth to an SGA infant (Medicina. 2020.56:352). Reducing the risk is critical, as adverse outcomes increase the risk for infant morbidity and mortality, as well as the development of chronic health conditions in adulthood. For example, PTB is positively correlated with all-cause mortality in adulthood, and both LBW and SGA increase the risk of type 2 diabetes (Braz J Psychiatry. 2022. 44: 201).
In a study in Canada, newborns of mothers with AN had up to six times the risk of hypothermia, hypoglycemia, infections, and perinatal death as neonates of healthy mothers (Can Fam Physician. 2003. 49:425).
Finally, when Dr. Cynthia Bulik and colleagues explored the impact of eating disorders on birth outcomes in the Norwegian Mother and Child Cohort Study, they found that pre-pregnancy body mass index was significantly lower in mothers with AN and higher in mothers with BED than among control women. Mothers with AN, BN, and BED reported greater weight gain during pregnancy, and more mothers with eating disorders reported smoking during pregnancy. Women with BED had higher birth weight babies, a lower risk of SGA babies, and a higher risk for LGA babies. The absence of differences in birth outcomes in women with AN and eating disorders not otherwise specified may reflect the small sample size and differential severity of illness in general population versus clinical samples. The detection of eating disorders in pregnancy could help identify modifiable factors (e.g., binge eating, smoking) that could influence birth outcomes. This systematic review and meta-analysis found that AN was positively correlated with LBW and SGA, BN with PTB, and BED with LGA.
The authors’ results are important reminders of factors that may influence birth outcomes within eating disorder populations, such as disease status during pregnancy (active or remittent) and that all of these, including gestational weight gain, should be investigated. The authors’ study emphasized the importance of screening for eating disorders among pregnant women, and a need for further studies.
