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.