Study: Eating disorders linked with negative pregnancy outcomes

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Swedish researchers have found that women with eating disorders-present or past-are at increased risk of adverse pregnancy and neonatal outcomes. Their findings point to a need for ob/gyns to screen and follow pregnant patients more carefully for conditions such as anorexia and bulimia.

Published in JAMA Psychiatry, the findings are from a population-based cohort study that looked at all singleton births in the Swedish Medical Register from January 1, 2003 to December 31, 2014. The authors compared more than 7,500 women with eating disorders to more than 1.2 million women without eating disorders.

Methods
Statistical analysis was performed from January 1, 2018 to April 30, 2019. Via linkage with the national patient register, women with eating disorders were identified and compared with women who had not eating disorders. The researchers also stratified eating disorders into active or previous disease based on last time of diagnosis.

This study, to the authors’ knowledge, is the only contemporary one based on an unselected study population to include three eating disorder subtypes and to attempt to differentiate between active and preexisting disease.  The eating disorders assessed were anorexia nervosa, bulimia nervosa, and eating disorder not otherwise specified (EDNOS).

Findings
The researchers found that all three subtypes of eating disorders were associated with an approximately 2-fold increased risk of hyperemesis during pregnancy (anorexia nervosa: relative risk [RR] 2.1, 95% confidence interval [CI] 1.8-2.5; bulimia nervosa: RR, 2.1, 95% CI, 1.6-2.7;  EDNOS: RR 2.6, 95% CI, 2.3-3.0). Risk of anemia during pregnancy was doubled in women who had active anorexia nervosa (RR 2.1, 95% CI, 1.3-3.2) or EDNOS (RR 2.1, 95% CI 1.5-2.8).

Maternal anorexia nervosa was associated with an increased risk of antepartum hemorrhage, a finding that the authors believe is novel (RR 1.6, 95% CI 1.2-2.1) and which was more pronounced in active versus previous disease. Women with anorexia nervosa (RR 0.7, 95% CI 0.6-0.9) and women with EDNOS (RR, 0.8, 95% CI 0.7-1.0) were at decreased risk of instrumental-assisted vaginal births; otherwise, there were no major differences in mode of delivery.

Risk of preterm birth was increased in women with all subtypes of eating disorders (anorexia nervosa: RR 1.6, 95% CI 1.4-1.8; bulimia nervosa: RR 1.3, 95% CI 1.0-1.6; EDNOS: RR 1.4, 95% CI 1.2-1.6). Risk of delivering an infant with microcephaly also was increased (anorexia nervosa: RR 1.9, 95% CI 1.5-2.4; bulimia nervosa: RR 1.6, 95% CI 1.1-2.4; EDNOS: RR 1.4, 95% CI 1.2-1.9).

Conclusions
The authors noted that their analysis was insufficient to determine whether body mass index is mediating the outcomes in the women with eating disorders. They said that “other and more specific measurements of nutritional status, including maternal weight gain throughout pregnancy, would be of interest to investigate as potential mediators.”

The findings, the researchers believe, should be generalizable to similar populations with similar demographic factors and health care settings. They emphasize “the importance of developing a reliable antenatal routine enabling identification of women with ongoing or previous eating disorders and considering extended pregnancy screening.”