Could the adoption of a Mediterranean diet improve pregnancy outcomes?

By Bhavana KunkalikarReviewed by Aimee MolineuxDec 29 2022

In a recent study published in JAMA Network Open, researchers explored the correlation between a Mediterranean diet pattern and adverse pregnancy outcomes (APOs).

Background

APOs are primary risk factors for maternal morbidity and mortality, highlighting the need for APO prevention to conserve and improve women's healthy lifespan. An APO history is regarded as a risk factor that necessitates more intensive lifestyle treatments for the primary prevention of cardiovascular disease, which is the primary reason for mortality among US females. The Mediterranean diet is described by the high consumption of plant-based foods like vegetables, fruits, legumes, monounsaturated fats, and nuts, as well as the low consumption of processed meats and saturated fats. Higher compliance with the Mediterranean diet has been correlated with a reduced risk of several chronic illnesses and mortality.

About the study

In the present study, researchers determined whether adherence to a Mediterranean diet around the time of delivery is connected with a reduced chance of developing any APO and specific APOs.

The present multicenter cohort study was performed at eight medical facilities in the United States between 1 October 2010 and 30 September 2013, enrolling 10,038 nulliparous females with single live births in their initial trimester and following them until delivery. Sociodemographic, medical, and lifestyle data were obtained at the first study visit. At the initial study visit between six and 13 weeks plus two days of gestation, the team employed the altered Block 2005 Food Frequency Questionnaire (FFQ) to evaluate the diet at the time of conception. This FFQ investigated dietary consumption over the past three months by questioning the quantity and the frequency of intake of around 120 beverages and food items to estimate the consumption of 35 food groups and 52 nutrients. The FFQ answered by the pregnant women was validated.

The conformance to a Mediterranean diet was established using the periconceptional diet data provided by the Block FFQ to calculate an alternate Mediterranean diet (aMed) score. All dietary factors were adjusted for optimal energy intake with the nutritional density method. The aMed score included nine components: vegetables, nuts, nuts, legumes, whole grains, fish, processed and red meats, the ratio of monounsaturated to saturated fat, and alcohol.

The primary study outcome involved APO occurrence which was the incidence of one or more events of the following: eclampsia or preeclampsia, prenatal hypertension, gestational diabetes, delivery before term, delivery of a newborn who is small-for-gestational-age, or stillbirth. In a secondary analysis, certain APOs were assessed. All results were evaluated by a team of maternal-fetal medical experts.

Results

The predominance of low, moderate, and high compliance to a Mediterranean diet around the time of conception was 38.2%, 31.2%, and 30.6%, respectively. Comparison of clinical and sociodemographic features across predefined aMed score categories showed that females having a higher aMed score had a higher chance of being non-Hispanic White, older, married, non-smokers, and have a higher level of education, and a lesser chance of having an obese category body-mass index (BMI). Compared to participants with a low aMed score, those with a high aMed score displayed lower APO prevalence, along with a significantly lower incidence of delivery of a newborn who is small for gestational age, and preeclampsia.

In multivariable models, those with a high aMed score were 21% less likely to develop any APO than those having a low aMed score. Furthermore, a high aMed score was related to a 28% risk reduction for eclampsia or preeclampsia and a 37% risk reduction for gestational diabetes. The team also noted no significant association between the aMed score and the chance of premature birth, prenatal hypertension, delivery of child who is small for gestational age, or stillbirth.

Plant-based foods were inversely related with APOs when evaluating the relationship between the components of the aMed score and the primary study outcome. Particularly, fruit, vegetable, and legume consumption were associated with a reduced chance of the development of any APO. Complying with the fish guideline displayed a significant association with a lower incidence of APO. The scores for whole grains, nuts, lipids, alcohol, and red meat were not considerably associated with the risk of developing APO. Greater consumption of fruits, vegetables, and fish were associated with a decreased risk of eclampsia and preeclampsia. In contrast, greater consumption of vegetables and lower consumption of processed and red meat were associated with a lower risk of gestational diabetes.

Conclusions

The study findings showed that at the time of conception, higher compliance to a Mediterranean diet was correlated to a lower risk of experiencing any APO, particularly eclampsia or preeclampsia and gestational diabetes. The team noted a dose-response relationship, suggesting that women who strongly adhered to this diet before conception exhibited the lowest probability of developing APOs.

Furthermore, higher consumption of fruits, vegetables, legumes, whole grains, and fish and lower consumption of processed and red meat was related to a lower risk of APOs. The researchers believe that adopting a Mediterranean diet may be a significant lifestyle intervention for preventing APOs.