"Assessing Diverse Periconceptional Dietary Approaches and Their Impact on Postpartum Cardiometabolic Risk: Toward Flexible Dietary Guidelines", School of Public Health Department of Epidemiology. 

Committee: 

• Lisa M. Bodnar (committee chair), EPI
• Malamo E. Countouris, Department of Medicine
• Samaneh Farsijani, EPI
• Marian Jarlenski, HPM

Abstract: 

Cardiometabolic conditions are increasingly common among reproductive-aged women in the US. Diet during the periconceptional period may be an important modifiable factor for prevention, yet its relation to postpartum cardiometabolic risk remains largely unknown. This dissertation examined three dimensions of periconceptional diet, plant-based dietary patterns, dietary diversity, and synergy between fruit and vegetable intake, in relation to postpartum cardiometabolic outcomes. We analyzed data from the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be Heart Health Study, a pregnancy cohort followed to a mean of 3 years postpartum. Usual dietary intake in the 3 months around conception was estimated from a food frequency questionnaire. Using doubly robust estimators with ensemble machine learning algorithms, we quantified associations between each dimension of periconceptional diet and postpartum metabolic syndrome and hypertension while adjusting for sociodemographic, medical, behavioral, and neighborhood confounders.

First compared with a periconceptional dietary pattern characterized as “Animal foods, high refined grains and added sugars”, dietary patterns characterized as “Mediterranean-based” and “Plant forward, high grains” were associated with 2 to 3 fewer cases of metabolic syndrome at a mean of 3 years postpartum. Second, greater periconceptional dietary diversity, measured as the number of distinct food and beverage items consumed that are encouraged for nutritional adequacy in the Dietary Guidelines for Americans, was associated with lower metabolic syndrome risk. The adjusted risk of decreased from 14.2 (95% CI: 10.5, 17.8) cases per 100 participants among those consuming 24 such items to 9.6 (95% CI: 8.1, 11.1) among those consuming 50 such items. Third, high intake of both fruits and vegetables was associated with 3.9 fewer cases of metabolic syndrome (95% CI: -9.8, 2) per 100 participants than expected under additivity. These results point to possible synergy between fruit and vegetable density, but results were imprecise. No associations were observed between any dimension of periconceptional diet and postpartum hypertension.

This dissertation suggests that multiple dimensions of periconceptional diet, including plant-based dietary patterns, and variety among foods recommended for nutritional adequacy, may support postpartum cardiometabolic health.