Abstract
INTRODUCTION: Epidemiological studies have linked prenatal maternal diet to fetal growth, but whether diet affects placental outcomes is poorly understood. METHODS: We collected past month dietary intake from 148 women in mid-pregnancy enrolled at University of California Los Angeles (UCLA) antenatal clinics from 2016 to 2019. We employed the food frequency Diet History Questionnaire II and generated the Healthy Eating Index-2015 (HEI-2015), the Alternate Healthy Eating Index for Pregnancy (AHEI-P), and the Alternate Mediterranean Diet (aMED). We conducted T(2)-weighted magnetic resonance imaging (MRI) in mid-pregnancy (1st during 14-17 and 2nd during 19-24 gestational weeks) to evaluate placental volume (cm(3)) and we measured placenta weight (g) at delivery. We estimated change and 95 % confidence interval (CI) in placental volume and associations of placenta weight with all dietary index scores and diet items using linear regression models. RESULTS: Placental volume in mid-pregnancy was associated with an 18.9 cm(3) (95 % CI 5.1, 32.8) increase per 100 gestational days in women with a higher HEI-2015 (≥median), with stronger results for placentas of male fetuses. We estimated positive associations between placental volume at the 1st and 2nd MRI and higher intake of vegetables, high-fat fish, dairy, and dietary intake of B vitamins. A higher aMED (≥median) score was associated with a 40.5 g (95 % CI 8.5, 72.5) increase in placenta weight at delivery, which was mainly related to protein intake. DISCUSSION: Placental growth represented by volume in mid-pregnancy and weight at birth is influenced by the quality and content of the maternal diet.