Maternal Adherence to Healthy Dietary Patterns During Pregnancy and Gestational Weight Gain

Background/Objectives: Suboptimal gestational weight gain (GWG) has been linked to increased risks of adverse maternal outcomes. Evidence linking diet in pregnancy to GWG remains limited. We assessed relationships between adherence to five dietary patterns (Planetary Health Diet [PHD], Dietary Approaches to Stop Hypertension [DASH], Alternate Mediterranean Diet [AMED], Healthy Eating Index [HEI], and Alternate Healthy Eating Index [AHEI]) and 2009 Institute of Medicine GWG categories. Methods: Women expecting singleton pregnancies participated in the NICHD Fetal Growth Studies and completed a food-frequency questionnaire (FFQ) at 8 to 13 weeks of gestation that captured their baseline diet. Adherence to each dietary pattern was calculated, with higher scores indicating greater adherence. Women were categorized into low, moderate or high adherence to each dietary pattern. Using multinomial logistic regression, we estimated adjusted odds ratios and 95% confidence intervals [OR (95% CIs)] of inadequate or excessive GWG (reference category: adequate), for high vs. low adherence to each dietary pattern. Results: In the full cohort, women with high vs. low adherence to DASH, AMED, HEI, or AHEI (but not PHD) had a 13% to 31% lowered odds of inadequate total GWG [ranging from 0.87 (0.58, 1.31) for AMED to 0.69 (0.48, 0.99) for DASH]. High adherence to DASH or HEI was associated with lower odds of inadequate first-trimester GWG, after correcting for multiple testing [DASH: 0.36 (0.22, 0.61), HEI: 0.49 (0.30, 0.79)]. No significant association was observed between any of the dietary patterns and excessive total and trimester-specific GWG. Conclusions: Greater adherence to several dietary patterns was associated with lowered odds of inadequate GWG. Future studies could characterize these diets objectively by identifying metabolite signatures and examining their associations with GWG.