Fatty acids intake and outcomes of assisted reproduction in women referring to an Italian Fertility Service: cross-sectional analysis of a prospective cohort study

Background: Infertility affects 15% of couples in Italy and approximately 10%–12% of couples worldwide. Focusing on female fertility, there are multiple causes, among which diet has a great influence. Methods: We investigated whether the consumption of certain fatty acids affects four outcomes of the assisted reproduction techniques. From September 2014 to December 2016, women referring to our Italian fertility unit, eligible for assisted reproduction techniques, were invited to participate. Information on diet was recorded through a validated food frequency questionnaire. Results: Four hundred and ninety-four women were included, of whom 95% achieved good quality oocytes, 87% achieved embryo transfer, 32.0% achieved clinical pregnancies and 24.5% achieved pregnancy at term. The fourth quartile of saturated fatty acids consumption, compared to the first one, showed an association with clinical pregnancy (adjusted relative risk 0.67, 95% confidence interval 0.45–1.00, p = 0.0491). Some associations emerge accounting for confounders. Age was associated with clinical pregnancy and pregnancy at term in the models considering all fatty intakes and food groups variables but was not associated with oocytes quality and embryo transfer. Physical activity was associated with clinical pregnancy. Conclusions: There is biological plausibility for the effect of omega-3 and omega-6 polyunsaturated fatty acids on oocyte development via synthesis of eicosanoids, even if only limited associations are shown in the present study. Future research should aim to measure the serum levels of fatty acids and investigate the outcomes of assisted reproduction techniques