Pregnancy Outcomes Associated with Maternal Adherence to Mediterranean Diet During Pregnancy in an Urban, Low-Income and Multiethnic US Population

Abstract

Abstract Objectives To evaluate associations between maternal adherence to Mediterranean-style diet during pregnancy and pregnancy outcomes. Methods The data originate from the Boston Birth Cohort (BMC), an urban, low-income, multiethnic cohort study which enrolled mother-infant dyads upon delivery at Boston Medical Center (Boston, MA) beginning in 1998. Demographic information and health history of mothers were obtained via interviewer-administered questionnaires, which also captured the maternal food and beverage intake during pregnancy using a food frequency questionnaire (FFQ). Pregnancy outcomes and other health information were extracted from medical records. A Mediterranean-style diet score (MSDS) was formulated based on the reported intake history, wherein each respondent was scored depending on their consumption of select food groups listed in the FFQ. MSDS was transformed into quintiles for analyses. Linear regression, logistic regression and multinomial logistic regression were performed to assess associations between MSDS quintiles and pregnancy outcomes, both overall and stratified by race. Results Among 7068 mother-infant dyads, 46.2% were black, 27.4% had preterm birth and 26.3% had low birth weight. Adjusting for eleven maternal sociodemographic and clinical factors, lowest MSDS quintile was associated with shorter gestation (−0.21 wk; 95% CI, −0.38– −0.04 wk) and lower birth weight (−63.4 g; 95% CI, −102.8– −24.0 g), compared to the other quintiles combined. This translated to higher relative risk (RR) of preterm delivery (1.18; 95% CI: 1.04–1.34) and of low birth weight (RR, 1.22; 95% CI, 1.07–1.39). When the analyses were limited to black mother-infant dyads, the associations were similar: lowest MSDS quintile was associated with shorter gestation (−0.28 wk; 95% CI, −0.54– −0.02 wk) and lower birth weight (−82.2 g; 95% CI, −141.1– −23.2 g), and greater risk of preterm delivery (RR, 1.19; 95% 0.99–1.44) and low birth weight (RR, 1.31; 95% CI, 1.08–1.58). Conclusions In this urban, low-income and multi-ethnic sample, lower adherence to Mediterranean-style diet was statistically significantly associated with adverse birth outcomes including preterm delivery and low birth weight. Funding Sources BMC (the parent study) is supported by the National Institutes of Health (NIH) grants (R01HD086013, 2R01HD041702 and R01HD098232).