Pregnancy complications and endometrial cancer in women with polycystic ovarian syndrome: a Korean National Health Insurance Service study.

Objective: Polycystic ovarian syndrome is associated with diverse pregnancy related complications and endometrial cancer. However, research on the relationship between pregnancy complications and endometrial cancer in women with polycystic ovarian syndrome is scarce. We aimed to examine the association between gestational diabetes mellitus, pregnancy induced hypertension, and preterm birth and the risk of endometrial cancer in women with polycystic ovarian syndrome.

Methods: We analyzed data from the National Health Information Database established by the Korean National Health Insurance Service between January 2002 and December 2019. We included women with gestational diabetes mellitus, pregnancy induced hypertension, preterm birth, and endometrial cancer from among the polycystic ovarian syndrome population. All conditions were diagnosed according to the Korean Informative Classification of Diseases, 10th revision codes. Age, area of residence, income, body mass index, waist circumference, total cholesterol, high density lipoprotein, low density lipoprotein, triglycerides, fasting blood sugar, and creatinine levels were included as covariates in the multiple logistic regression analysis.

Results: Of 467 221 women with polycystic ovarian syndrome included, 5099 had endometrial cancer. Age, residence, income, body mass index, waist circumference, total cholesterol, high density lipoprotein, low density lipoprotein, triglycerides, fasting blood sugar, and creatinine levels differed significantly between the endometrial cancer and non-endometrial cancer groups (p≤0.001-0.032). Among the polycystic ovarian syndrome population, the odds ratios (ORs) of endometrial cancer were 1.50, 1.43, and 1.23 in women with a history of gestational diabetes mellitus, pregnancy induced hypertension, and preterm birth, respectively, compared with those without a history of these conditions (OR 1.50, 95% confidence interval (CI) 1.32 to 1.69, p<0.001; 1.43, 1.04 to 1.97, p=0.027; and 1.23, 1.05 to 1.45, p=0.011, respectively).

Conclusion: Our results suggest that a history of pregnancy complications (gestational diabetes mellitus, pregnancy induced hypertension, and preterm birth) increases the risk of endometrial cancer in women with polycystic ovarian syndrome.