Gender of offspring and risk of ovarian cancer: The HOPE study

Objective: To examine the association between gender of offspring and epithelial ovarian cancer (EOC). Methods: We compared gender of offspring between 664 incident EOC cases and 1531 controls participating in a population-based study conducted in Pennsylvania, Ohio, and New York from 2003–2008. Multivariable unconditional logistic regression was used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs) adjusting for potential confounders. Results: Bearing a male offspring was associated with an 8 % lower EOC risk; bearing all boys was associated with an 11 % lower risk. Compared to bearing all girls, bearing all boys was associated with a 14 % decrease risk. Increasing number of male offspring increased the protective effect (adjusted-OR: 0.92, 0.91, 0.84, for 1, 2, and 3+ boys compared to all girls). Results where similar when limiting cases to invasive disease and to the high-grade serous histotype. Conclusion: Fetal sex, which influences maternal hormonal milieu, may impact EOC risk.