Dietary patterns and difficulty conceiving: a nested case-control study

Objective: To investigate potential associations between dietary patterns (defined using factor analysis) and difficulty conceiving. Design: Case-control study nested in a Spanish cohort of university graduates (Seguimiento Universidad de Navarra [SUN] Project). Setting: Female university graduates all over Spain participating in the SUN Project. Patient(s): A total of 485 women, aged 20-45 years, reporting having presented with difficulty getting pregnant, and 1,669 age-matched controls who had at least one child. Intervention(s): None. Main Outcome Measure(s): Reported difficulty getting pregnant. Data were collected from baseline and follow-up questionnaires of the SUN Project. Result(s): Two dietary patterns were identified. They were labeled as Mediterranean-type and Western-type patterns. A lower risk of difficulty getting pregnant was apparent in the highest quartile of adherence to the Mediterranean-type pattern compared with the lowest quartile (odds ratio 0.56, 95% confidence interval 0.35-0.95). Greater adherence to the Western-type dietary pattern showed no association with this outcome. Conclusion(s): A greater adherence to the Mediterranean-type dietary pattern may enhance fertility. Further evidence about the relationship between this dietary pattern and fertility is needed to develop nutritional interventions for women desiring to get pregnant. (Fertil Steril (R) 2011;96:1149-53. (C) 2011 by American Society for Reproductive Medicine.)