Anorexia nervosa in pregnancy linked to adverse neonatal outcomes

Key takeaways:

• Anorexia was linked to preterm labor, small for gestational age, low birth weight and preterm birth.
• Having underweight mediated preterm births and small for gestational age deliveries.

Anorexia nervosa during pregnancy was associated with several adverse neonatal outcomes, such as preterm and small for gestational age birth, compared with women without eating disorders, researchers reported.

“People with a diagnosis of anorexia nervosa during pregnancy have a higher risk of adverse live-born birth outcomes — such as severe maternal morbidity, a small for gestational age or low birth weight infant, and a baby born preterm — compared with people without an eating disorder diagnosis. A large amount of this excess risk is mediated by less than the recommended weight gain during pregnancy,” Rebecca J. Baer, MPH, senior statistician in the department of pediatrics at the University of California, San Diego, and the California Preterm Birth Initiative at the University of California, San Francisco, told Healio. “Treating anorexia nervosa prior to and during pregnancy and counseling patients about healthy weight gain during pregnancy may improve live-birth pregnancy outcomes among people with anorexia nervosa.”

Baer and colleagues evaluated a sample of live-born singletons born from 2007 to 2021 from the Study of Outcomes in Mothers and Infants database. Anorexia nervosa diagnosis was obtained from the ICD codes on hospital discharge records. Adverse pregnancy outcomes included gestational diabetes, gestational hypertension, preeclampsia, anemia, antepartum hemorrhage, premature rupture of the membranes, premature labor, cesarean delivery, oligohydramnios, placenta previa, chorioamnionitis, placental abruption, severe maternal morbidity, small for gestational age, large for gestational age, low birth weight and preterm birth.

For all included live-born singletons, 241 were born to women with an anorexia nervosa diagnosis and 6,418,236 were born to women without an eating disorder diagnosis. Of those with anorexia nervosa, 7.88% had a co-occurring eating disorder.

In adjusted models, women with anorexia nervosa during pregnancy had a higher likelihood of having anemia (adjusted RR = 1.45; 95% CI, 1.13-1.85), preterm labor with term birth (aRR = 1.82; 95% CI, 1.34-4.49), oligohydramnios (aRR = 2.52; 95% CI, 1.62-3.9), severe maternal morbidity (aRR = 1.85; 95% CI, 1.1-3.13), small for gestational age infants (aRR = 1.9; 95% CI, 1.43-2.51), low birth weight infants (aRR = 1.7; 95% CI, 1.2-2.42) and delivery at 32 to 36 weeks gestation (aRR = 2.55; 95% CI, 1.63-4) compared with women without an eating disorder.

Having an underweight prepregnancy BMI mediated 7.78% of excess preterm births and 18% of excess small for gestational age infants. Gestational weight gain below the ACOG recommendation mediated 38.89% of excess preterm births and 40.44% of excess low birth weight infants. In addition, having both underweight prepregnancy BMI and gestational weight gain below what is recommended by ACOG mediated 24.91% of excess preterm births and 20.13% of excess small for gestational age infants.

“It will be important to test interventions to support adequate weight gain and to examine if a prepregnancy weight and weight gain during pregnancy can reduce or eliminate the excess risk of adverse outcomes among people with anorexia nervosa,” Baer said.

For more information:

Rebecca J. Baer, MPH, can be reached at rjbaer@health.ucsd.edu.