Mediterranean diet and outcomes of assisted reproduction: an Italian cohort study

BACKGROUND: Detrimental lifestyle habits have been indicated as potential causes of reduced fertility. Recently studies have suggested an association between healthy diets and increased live birth rates after assisted reproduction techniques. However, the issue remains under debate, and evidence is still accumulating. OBJECTIVE: The objective of the study was to study the relationship between a Mediterranean diet and outcomes of assisted reproduction techniques in subfertile couples in an Italian population. STUDY DESIGN: This was a prospective cohort study, conducted in an Italian fertility clinic. Couples undergoing in vitro fertilization were interviewed on the day of oocyte retrieval to obtain information on personal and health history, lifestyle habits, and diet. Adherence to a Mediterranean diet was evaluated using a Mediterranean diet score. Relative risks and 95% confidence intervals for embryo transfer, clinical pregnancy, and live birth were calculated. Potential confounders were included in the equation model. RESULTS: Among 474 women (mean age, 36.6 years, range, 27-45), 414 (87.3%) performed embryo transfer, 150 (31.6%) had clinical pregnancies, and 117 (24.7%) had live births. In a model including the potential confounders (age, leisure physical activity, body mass index, smoking, daily calorie intake, and previous failed in vitro fertilization cycles), findings showed that the Mediterranean diet score was not significantly associated with in vitro fertilization outcomes. Adjusted analyses were performed in strata of age, previous assisted reproduction technique cycles, and reasons for infertility, with consistent findings. The only exception was observed in women >35 years old with an intermediate Mediterranean diet score, who showed a lower risk of not achieving clinical pregnancy (adjusted relative risk, 0.84, 95% confidence interval, 0.71-1.00, P =.049). CONCLUSION: No clear association was observed between adherence to a Mediterranean diet and successful in vitro fertilization.