Lack of a meaningful association between dietary patterns and in vitro fertilization outcome among Japanese women

PURPOSE: The purpose of this study was to examine whether preconception maternal dietary pattern is associated with in vitro fertilization (IVF) outcome among Japanese women. METHODS: This prospective study included 140 Japanese women who underwent conventional‐IVF/intracytoplasmic sperm injection. The patients’ diets during the previous month before egg retrieval were assessed with validated brief‐type self‐administered diet history questionnaire. Dietary patterns from 33 predefined food groups [energy‐adjusted food (g/1000 kcal)] were extracted by factor analysis. The primary outcome measure was clinical pregnancy rate after IVF. RESULTS: Thirty‐six women had confirmed clinical pregnancy. Three dietary patterns were identified: “Vegetable and seafood,” “Western,” and “Rice and miso soup.” The “Vegetables and seafood” dietary pattern (high intakes of green and other vegetables, mushrooms, seasoning, fish, soy products, chicken, and potatoes) was not associated with clinical pregnancy ([odds ratio per one‐quartile increase in dietary pattern: 0.94 (95% confidence interval: 0.67‐1.32), P = 0.73]. This relationship was unaltered after controlling for potential confounders. Furthermore, no association was seen between the other two dietary patterns and clinical pregnancy. CONCLUSIONS: The three maternal preconception dietary patterns identified revealed no meaningful association with IVF outcome in Japanese women. Further studies in various populations with different dietary patterns are needed to confirm these findings.