A Mediterranean Diet with an Enhanced Consumption of Extra Virgin Olive Oil and Pistachios Improves Pregnancy Outcomes in Women Without Gestational Diabetes Mellitus: A Sub-Analysis of the St. Carlos Gestational Diabetes Mellitus Prevention Study.

AIMS: The aim of the study was to evaluate the effect of a Mediterranean diet (MedDiet), enhanced with extra virgin olive oil (EVOO) and nuts, on a composite of adverse maternofoetal outcomes of women with normoglycemia during pregnancy.

METHODS: This was a sub-analysis of the St Carlos gestational diabetes mellitus Prevention Study. Only normoglycemic women were analysed (697). They were randomized (at 8-12th gestational weeks) to: standard-care control group (337), where fat consumption was limited to 30% of total caloric intake; or intervention group (360), where a MedDiet, enhanced with EVOO and pistachios (40-42% fats of total caloric intake) was recommended. The primary outcome was a composite of maternofoetal outcomes (CMFOs): at least having 1 event of emergency C-section, perineal trauma, pregnancy-induced hypertension and preeclampsia, prematurity, large-for-gestational-age and small-for gestational-age.

RESULTS: Crude relative risk showed that the intervention was associated with a significant reduction in the risk of CMFOs (0.48 [0.37-0.63]; p = 0.0001), with a number-needed-to-treat = 5. Risk of urinary tract infections, emergency C-sections, perineal trauma, large-for-gestational-age and small-for gestational age new-borns were also significantly reduced.

CONCLUSION: A MedDiet, enhanced with EVOO and nuts, was associated with a risk reduction of CMFOs in over 50% in normoglycemic pregnant women. Therefore, it might be a potentially adequate diet for pregnant women.

TRIAL REGISTRATION: Identifier ISRCTN84389045. The study was registered on September 27, 2013. Last edited on September 26, 2018.