Risk of gestational hypertension-preeclampsia in women with preceding endometriosis: A nationwide population-based study

To investigate the association between preceding endometriosis and gestational hypertension-preeclampsia (GH-PE). In this nationwide population-based longitudinal study, data from 1998-2012 Taiwan National Health Insurance Research Database were used. We used ICD9-CM codes 617.X and 642.X respectively for the diagnoses of endometriosis and GH-PE, which were further confirmed by examining medical records of surgeries, blood pressure and urine protein to ensure the accuracy of the diagnoses. The study excluded women diagnosed with endometriosis at < 15 or > 45 years of age, chronic hypertension, and GH-PE prior to endometriosis. Each pregnant woman with a prior diagnosis of endometriosis was matched to 4 pregnant women without endometriosis by age. Logistic regression analysis was used to calculate odds ratios (ORs) for the risk of GH-PE with adjustment for age, occupation, urbanization, economic status and comorbidities. Among 6,300 women with a prior endometriosis diagnosis who were retrieved from a population of 1,000,000 residents, 2,578 (40.92%) had subsequent pregnancies that were eligible for further analysis and were compared with 10,312 pregnant women without previous endometriosis. GH-PE occurred more in women with prior endometriosis as compared to those without endometriosis (3.88% vs. 1.63%, p