Does encouraging concordance to a Mediterranean diet in the periconception period reduce the risk of adverse pregnancy outcomes including preeclampsia or eclampsia, gestational hypertension or diabetes, preterm/stillbirth, or a small-for-gestational-age infant?

A research team from across the United States sought to determine the answer to this question by examining the impact of diet on adverse pregnancy outcomes. For this they included women who were a part of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b). out of the 10 038 women enrolled between October 2010 and September 2013, 7798 women, mean age 27.4 years, with singleton pregnancies were enrolled in the current multicenter study.¹ A food frequency questionnaire was used to obtain information about diet in the 3 months of periconceptional period at the time of the first visit during the first trimester. Based on this data, an Alternate Mediterranean Diet (aMed) score was calculated as low (0-3), moderate (4-5) and high (6-9). High scores were indicative of greater adherence to the Mediterranean diet.

Results published in JAMA Network Open showed that the mean aMed score was estimated to be 4.3. High concordance to a Mediterranean diet around the time of conception was observed in 30.6% or 2388 women. Around 31% or 2430 women had moderate concordance, while the concordance was low in 38% or 2980 participants.

The probability of any adverse pregnancy outcomes decreased by 21% among women with high aMed scores compared to those with low aMed scores (adjusted odds ratio 0.79). Those who scored high on aMed were also at a 37% lower risk of gestational diabetes (aOR 0.63) and 28% reduced risk of preeclampsia or eclampsia (aOR 0.72). Although differences were observed for  race, ethnicity, and prepregnancy body mass index (BMI), the associations were stronger among women aged 35 years or older (aOR 0.54).

This study adds to the evidence that eating a Mediterranean diet reduces the risk of adverse pregnancy outcomes with a dose-response association. The authors advocate long-term intervention trials to study if encouraging women to adopt a Mediterranean-style diet around the time of conception and throughout pregnancy could prevent adverse pregnancy outcomes.

Reference

1. Makarem N, et al. Association of a Mediterranean diet pattern with adverse pregnancy outcomes among US women. JAMA Netw Open. 2022 Dec 1;5(12):e2248165. doi: 10.1001/jamanetworkopen.2022.48165.