Maternal, Perinatal and Pediatric Nutrition
Objectives : Vegetarian diets appear to reduce risk of chronic disease in the general population, but the possible effect on fetal growth is understudied. Our aim was to examine associations of gestational vegetarianism (self-defined and operationalized) with neonatal anthropometry.
Methods : We studied 1964 women who had a singleton livebirth in a diverse multi-site cohort of U.S. pregnant women (2009-2013). To assess peri-conception and first trimester diet, women completed a 145-item self-administered Food Frequency Questionnaire at enrollment (8-13 weeks’ gestation). Self-defined vegetarians said “yes” to the question “For all of the past 3 months, did you follow a vegetarian diet?”. Operationalized vegetarianism was defined based on servings of first trimester meat, poultry, and fish (MPF) intake (vegetarian = MPF < 1 month; pesco-vegetarian = MP < 1 month and fish ≥ 1 month; semi-vegetarian= MPF ≥ 1 month and < 1 week). Birthweight was abstracted from medical records and neonatal anthropometrics (upper-arm length, upper-thigh length, head circumference, abdominal circumference, skinfold thickness) were measured post-delivery using a standard protocol. Linear regression was used to model neonatal outcomes. To assess the association of vegetarianism with gestational age, we also used cox proportional hazards models to estimate time to delivery.
Results : There were 99 (6.03%) self-defined, 32 (1.91%) operationalized, 7 (0.42%) pesco- and 321 (19.12%) semi-vegetarians. Neonates of vegetarians had significantly lower birth weight and birth length than nonvegetarians in adjusted models (Figure). Associations with all other measures of neonatal anthropometrics were null. Time to delivery HR (95% CI) was 1.08 (0.88, 1.34), 0.94 (0.65, 1.24), 0.68 (0.32, 1.45), and 0.96 (0.84, 1.10) for self-defined, operationalized, pesco- and semi-vegetarians respectively.
Conclusions : Both self-defined and operationalized vegetarianism was significantly associated with decreased birth weight and birth length. Further work is needed to better understand the impact of this maternal diet on the neonate.
Funding Sources : Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development