Could Adopting a Mediterranean Diet Improve Pregnancy Outcomes?

In a recent study published in Open JAMA Networkresearchers explored the correlation between a Mediterranean diet and adverse pregnancy outcomes (APO).

Background

APOs are major risk factors for maternal morbidity and mortality, highlighting the need for APO prevention to maintain and improve women’s healthy lifespan. A history of APO is considered a risk factor that requires more intensive lifestyle treatments for the primary prevention of cardiovascular disease, which is the leading cause of death among American women. The Mediterranean diet is described by high consumption of plant-based foods like vegetables, fruits, legumes, monounsaturated fats, and nuts, as well as low consumption of processed meats and saturated fats. Greater adherence to the Mediterranean diet has been correlated with a reduced risk of several chronic diseases and mortality.

About the study

In the current study, researchers determined whether adherence to a Mediterranean diet at the time of childbirth is related to a reduced risk of developing specific APOs and APOs.

The present multicenter cohort study was performed at eight medical institutions in the United States between October 1, 2010 and September 30, 2013, recruiting 10,038 nulliparous women with single live births during their first trimester and following them until at childbirth. 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 used the Block 2005 Modified Food Frequency Questionnaire (FFQ) to assess diet at the time of conception. This FFQ investigated the food consumption of the last three months by asking about the quantity and frequency of consumption of approximately 120 drinks and foods to estimate the consumption of 35 food groups and 52 nutrients. The FFQ answered by pregnant women has been validated.

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

The primary endpoint of the study concerned the occurrence of APO, which was the incidence of one or more of the following events: eclampsia or preeclampsia, prenatal hypertension, gestational diabetes, preterm delivery, delivery of a new -born small for gestational age or stillbirth. In a secondary analysis, some APOs were evaluated. All results were evaluated by a team of maternal-fetal medical experts.

Results

The prevalence of low, moderate, and high compliance with a Mediterranean diet at the time of conception was 38.2%, 31.2%, and 30.6%, respectively. Comparison of clinical and sociodemographic characteristics within predefined aMed score categories showed that women with higher aMed scores were more likely to be non-Hispanic white, older, married, non-smokers, and had lower higher education, and a lower chance of having a body mass index (BMI) in the obese category. Compared to participants with a low aMed score, those with a high aMed score had a lower prevalence of APO, as well as a significantly lower incidence of delivering a small-for-gestational-age newborn and preeclampsia.

In multivariate models, people with a high aMed score were 21% less likely to develop POA than those with a low aMed score. Additionally, a high aMed score was linked to a 28% reduction in the risk of eclampsia or preeclampsia and a 37% reduction in the risk of gestational diabetes. The team also found no significant association between the aMed score and the risk of preterm birth, prenatal hypertension, delivery of a small-for-gestational-age child, or stillbirth.

Plant-based foods were inversely related to APOs when assessing the relationship between aMed score components and the primary study outcome. In particular, the consumption of fruits, vegetables and legumes was associated with a reduced risk of developing any APO. Compliance with the guideline for fish showed a significant association with a lower incidence of APO. Scores for whole grains, nuts, fat, alcohol, and red meat were not significantly associated with the risk of developing APO. Higher consumption of fruits, vegetables and fish was associated with a lower risk of eclampsia and preeclampsia. In contrast, higher vegetable intake and lower processed and red meat intake were associated with a lower risk of gestational diabetes.

conclusion

Study results showed that at the time of conception, greater adherence to a Mediterranean diet was correlated with a lower risk of experiencing APO, particularly eclampsia or preeclampsia and gestational diabetes. The team noted a dose-response relationship, suggesting that women who adhered strongly to this diet before conception had the lowest likelihood of developing APO.

Additionally, higher consumption of fruits, vegetables, legumes, whole grains, and fish and lower consumption of processed and red meat were linked to a lower risk of APO. Researchers believe that adopting a Mediterranean diet may be an important lifestyle intervention to prevent OPAs.