536: Obesity during pregnancy: a risk factor for future development of ovarian and breast cancer

To investigate whether patients with a history of obesity during pregnancy have an increased risk for subsequent maternal female malignancies. A population-based study compared the incidence of long-term female malignancies in a cohort of consecutive women with and without a diagnosis of obesity during pregnancy. Deliveries occurred between the years 1988-2013, with a mean follow-up duration of 12 years. Excluded from the study were women with known malignancies prior to index pregnancy. Female malignancies were divided according to specific type including ovary, uterine, breast and uterine cervix. Kaplan-Meier survival curve was used to estimate cumulative incidence of malignancies. Cox proportional hazards models were used to estimate the adjusted hazard ratios (HR) for female malignancy. During the study period 106,251 deliveries met the inclusion criteria; 2.2% (n=2360) occurred in patients with a history of obesity during past pregnancy. During the follow-up period patients with obesity during pregnancy had a significantly increased risk for hospitalizations due to female malignancies as a group and specifically ovarian and breast cancer (table). Using a Kaplan-Meier survival curve, patients with a previous diagnosis of obesity during pregnancy had a significantly higher cumulative incidence of female malignancies (Figure). Using a Cox proportional hazards model, adjusted for confounders such as diabetes mellitus, parity and maternal age, obesity during pregnancy remained independently associated with long-term risk for female malignancies (adjusted HR 1.4; 95% CI 1.1-1.9; P=0.045). Obesity during pregnancy is an independent risk factor for long-term female malignancies such as ovarian and breast cancer. Pregnancy is a unique window of opportunity that has an important role in promoting life style modifications. As obstetricians we should remember to consult our patients not only regarding obstetrical issues but also about long term consequences.