The new research was published in the Journal of the American Medical Association’s Nutrition Obesity and Exercise publication. It was the work of a large group of researchers associated with medical schools and hospitals across the US, including New York, California, Pennsylvania, Indiana, Illinois and North Carolina.
The study used data culled from a larger effort called the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be, which enrolled more than 10,000 subjects who were followed in the 2010-2013 timeframe. Almost 7,800 women completed the study, making up a cohort that was racially, ethnographically and geographically diverse. The cohort averaged about 27 years of age, with only 9.7% being older than 35.
The researchers noted that suboptimal diets are common among pregnant women in the US. Improving those diets is a primary target for reducing averse pregnancy outcomes (APOs), they said.
The researchers defined a Mediterranean diet as “characterized by high intake of plant-based foods, such as vegetables, legumes, fruits, nuts, and monounsaturated fats, coupled with a low intake of saturated fats and processed meats.” They noted that many studies have linked the diet pattern with health and longevity.
Few studies have looked at Med diet in relation to pregnancy
However, there is less information regarding its effect on pregnancy. While there is as wealth of information on the health effects of the dietary approach generally, the authors said there are only three studies that look at it specifically in connection to APOs.
The researchers defined an APO as “gestational hypertension, preeclampsia or eclampsia, gestational diabetes, preterm birth (medically indicated or spontaneous live birth at <37 weeks’ gestational age; assessed as both a composite and as spontaneous or iatrogenic preterm birth), delivery of a small-for-gestational-age infant (<5th percentile by Alexander nomogram), or stillbirth.”
Coming up with a diet scorecard
To assess the study cohort’s exposure to the Mediterranean diet, the researchers came up with a score. This was adapted from previous research dating back to as far as 2003. The score is based on the relative intakes of nine components: vegetables (excluding potatoes), fruits, nuts, whole grains, legumes, fish, monounsaturated to saturated fat ratio, red and processed meats, and alcohol. The scores ranged from 0 to 9, based on how closely the subject’s diet matched the ‘ideal,’ with nine being the best score.
The researchers found the average diet score of the 7,798 women was 4.3. For statistical purposes, the researchers divided the group up into three subgroups: low, medium and high scorers. The high scoring group tended to be older and skewed more heavily toward being non-Hispanic White, married, having higher incomes and being less likely to be obese, and none of them were smokers.
When associating the subgroups’ diet preferences with the prevalence of APOs the researchers found that the high scoring group was 21% less likely to suffer these complications either for themselves or their offspring.
Risk of some complications cut by more than half
When matching individual APOs with an analysis of the cohort by quintiles, the researchers found that those in the highest vs lowest quintile had 35% lower odds of any preeclampsia or eclampsia and 54% lower odds of gestational diabetes.
"A Mediterranean diet pattern is associated with lower risk of developing any APO and multiple individual APOs in US women, with evidence of a dose-response association. Our findings add to the growing body of evidence demonstrating that the Mediterranean diet pattern may play an important role in preserving the health of women across the lifespan, including during pregnancy. Long-term intervention studies are needed to assess whether promoting a Mediterranean-style diet pattern around the time of conception and throughout pregnancy can prevent APOs or reduce their downstream associations with future CVD risk. This may be particularly useful to study in pregnant persons at high risk for APOs,” the authors concluded.
Source: Nutrition, Obesity and Exercise
doi: 10.1001/jamanetworkopen.2022.48165
Association of a Mediterranean Diet Pattern With Adverse Pregnancy Outcomes Among US Women
Authors: Makarem N, et al.
