The Mediterranean diet is the best dietary pattern for pregnant women, according to a 2022 US study. (1)
The Med Diet has been shown to be associated with a low risk of contracting adverse outcomes during pregnancy, also called Adverse Outcome of Pregnancy (APO) factors. With its intake of minimally processed, plant-based foods combined with low intake of saturated fats and processed meats, it provides health and longevity and is confirmed as the world’s best diet for the sixth consecutive year in the North American rankings as well (2).
Introduction
A report (3) by the Centers for Disease Control and Prevention’s National Center for Health Statistics in 2022 indicates that pregnancy-related mortality in the United States has steadily increased over the past 30 years with significant disparities by race and maternal age.
APOs emerged as the main factors associated with maternal morbidity and mortality, underscoring the importance of prevention.
APO-Adverse Outcome of Pregnancy
Adverse pregnancy outcomes (APO) occur in 17-20% of pregnancy cases in the US. They include
– hypertensive disorders of pregnancy (HDP), such as preeclampsia and gestational hypertension,
– gestational diabetes mellitus (GDM),
– preterm delivery,
– Infants small for gestational age (SGA).
APOs can cause short-term complications during pregnancy, but they are increasingly found to be associated with long-term complications, particularly cardiovascular disease (CVD-CardiovascularDisease), such as coronary artery disease, stroke, or heart failure (4).
Factors affecting APOs and the U.S. study
In addition to genetic factors (race, ethnicity, age etc.), the role of social determinants of health (level of education, social status) (5) , previously linked to APOs and known to influence dietary habits, is crucial on the likelihood of contracting APOs.
The recent association study between diet and APOs aims to fill this knowledge gap by evaluating the association of an aMed score, which includes foods characteristic of the Mediterranean model but adapted to the U.S. population, and its components, with the likelihood of developing any APO and individual APOs.
The NuMoM2b study
The study is part of a larger prospective research: Nulliparous Pregnancy Outocomes Study, Monitoring Mothers-to-Be or NuMoM2b (6), which is currently underway.
The goal of NuMoM2b is to determine maternal characteristics (genetic, physiological pregnancy response factors) and environmental characteristics that predict adverse pregnancy outcomes: spontaneous preterm delivery, preeclampsia, and fetal growth restriction.
The data collected from the study came from the observation of 10,038 nulliparous women (women with no significant pregnancy history) in the first trimester of geographically, racially and ethnically diverse pregnancies.
Relationship between Mediterranean diet and pregnancy
Compliance with the Mediterranean diet was established using diet data collected through aFood Frequency Questionnaire(FFQ) where women reported details of food intake during the 3 months prior to pregnancy (periconcenational period).
An aMed score was then developed including nine components: vegetables, nuts, dried fruits (7), legumes, whole grains, fish, processed and red meat, ratio of monounsaturated to saturated fat, and alcohol.
The scores set ranged from 0 to 9, based on how well the subject’s diet matched the Mediterranean diet pattern, with nine being the best score.
Results
Among the results obtained, a dose-response relationship was observed, indicating that women who strongly adhered to this diet before conception showed
- -21% chance of contracting any adverse pregnancy outcome (preeclampsia, preterm delivery, gestational hypertension, gestational diabetes mellitus, small-for-gestational-age infant, or stillbirth),
- -28% preeclampsia risk,
- -38% risk of gestational diabetes.
Influence of foods of the Mediterranean diet in the reduction of APOs
The aMed score was used to correlate the foods predicted by the Mediterranean model with the reduction in APO factors:
1 Med Diet correlation with nonspecific APO pathologies.
Plant-based foods were found to be inversely associated with the development of APO disease.
Consumption of fruits, vegetables and legumes has been associated with a lower likelihood of developing any APO, as has fish.
Scores for whole grains, nuts, lipids, alcohol, and red meat were not significantly associated with the risk of developing APO.
2 Med Diet correlation with specific APO pathologies.
In the analyses that assessed the associations of aMed score components with individual APOs, different associations were observed.
Higher consumption of fruits, vegetables, and fish was associated with lower risk of eclampsia and preeclampsia.
In contrast, higher consumption of vegetables and lower consumption of processed and red meat were associated with lower risk of gestational diabetes.
Aging women and benefits
It was also found that the benefits of the Mediterranean diet may be greater for pregnant women aged 35 and older, whose risk of adverse pregnancy outcomes is high.
For women under 35 years of age of all races, ethnicities, and body weights, however, the benefit of the Med Diet does not show significant variation.
Conclusion and future prospects
The role of nutrition is confirmed to be crucial for the healthy development of the fetus and future baby and for women’s health (8).
Dietary recommendations during pregnancy continue to evolve as researchers gain new insights into best nutrition and its impacts. Therefore, collaboration with diabetologists and nutrition experts should not fail to establish healthy eating patterns during pre- and post-pregnancy.
Giulia Pietrollini
Notes
(1) Makarem N, Chau K, Miller EC, et al. Association of a Mediterranean Diet Pattern With Adverse Pregnancy Outcomes Among US Women. JAMA Netw Open. 2022;5(12): e2248165. doi: 10.1001/jamanetworkopen.2022.48165
(2) Best Diets Overall 2023 – Expertly Reviewed – US News Health https://health.usnews.com/best-diet/best-diets-overall
(3) 1. Hoyert DL. Maternal mortality rates in the United States, 2020. Centers for Disease Control and Prevention. February 23, 2022. Accessed June 1, 2022. https://stacks.cdc.gov/view/cdc/113967
(4) Minhas AS, Ying W, Ogunwole SM, Miller M, et al. The Association of Adverse Pregnancy Outcomes and Cardiovascular Disease: Current Knowledge and Future Directions. Curr Treat Options Cardiovasc Med. 2020 Dec;22(12):61. doi: 10.1007/s11936-020-00862-6. Epub 2020 Oct 31. PMID: 35296064; PMCID: PMC8923621.
(5) Premkumar A, Debbink MP, Silver RM, et al. Association of Acculturation With Adverse Pregnancy Outcomes. Obstet Gynecol. 2020 Feb;135(2):301-309. doi: 10.1097/AOG.0000000000003659. PMID: 31923068; PMCID: PMC7054005.
(6) Haas DM, Parker CB, Wing DA, et al. NuMoM2b study. A description of the methods of the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be (nuMoM2b). Am J Obstet Gynecol. 2015 Apr;212(4):539.e1-539.e24. doi: 10.1016/j.ajog.2015.01.019. Epub 2015 Jan 31. PMID: 25648779; PMCID: PMC4387083.
(7) Marta Strinati. Dried fruits in pregnancy, babies with better learning ability. GIFT (Great Italian Food Trade). 14.5.19
(8) Elena Bosani. Organic diet and few pollutants to protect children’s cognitive system. The Human Early-Life Exposome Study. GIFT (Great Italian Food Trade). 27.3.21
Graduated in industrial biotechnology and passionate about sustainable development.
