The preconception Mediterranean dietary pattern in couples undergoing in vitro fertilization/intracytoplasmic sperm injection treatment increases the chance of pregnancy.

OBJECTIVE To investigate associations between preconception dietary patterns and IVF/intracytoplasmic sperm injection (ICSI) outcomes validated by biomarkers of the homocysteine pathway. DESIGN Observational prospective study. SETTING A tertiary referral fertility clinic at the Erasmus University Medical Centre, Rotterdam, The Netherlands. PATIENT(S) One hundred sixty-one couples undergoing IVF/ICSI treatment. INTERVENTION(S) No interventions other than the Dutch governmental recommendation of folic acid. MAIN OUTCOME MEASURE(S) Dietary patterns, blood and follicular fluid concentrations of folate, vitamin B12, vitamin B6, homocysteine, and fertilization rate, embryo quality, and pregnancy. RESULT(S) In women, two dietary patterns were identified. The "health conscious-low processed" dietary pattern (variation explained 12.1%) was characterized by high intakes of fruits, vegetables, fish, and whole grains and low intakes of snacks, meats, and mayonnaise, and positively correlated with red blood cell folate (β=0.07). The "Mediterranean" dietary pattern (variation explained 9.1%), that is, high intakes of vegetable oils, vegetables, fish, and legumes and low intakes of snacks, was positively correlated with red blood cell folate (β=0.13), and vitamin B6 in blood (β=0.09) and follicular fluid (β=0.18). High adherence by the couple to the "Mediterranean" diet increased the probability of pregnancy, odds ratio 1.4 (95% confidence interval 1.0-1.9). CONCLUSION(S) A preconception "Mediterranean" diet by couples undergoing IVF/ICSI treatment contributes to the success of achieving pregnancy.