Maternal complications in women with chronic hypertension: a population-based cohort study

BACKGROUND: The aim of the study was to determine if pregnant women with chronic hypertensive disease have an independent risk for preeclampsia, gestational diabetes or placental abruption. To examine if superimposed preeclampsia in this group of women is related to an increased risk of placental abruption. METHODS: This study is a population-based cohort study using the Swedish Medical Birth Register 1992-98. A population of 681 515 women aged between 15-44 years with singleton pregnancies, excluding women with systemic lupus erythematosus (SLE), diabetes mellitus and chronic renal disease were studied. Among these, 3374 women were diagnosed with chronic hypertensive disease. Multiple logistic regression analysis was performed and the outcome measures of crude and adjusted odds ratios (OR) were presented with 95% confidence intervals (CI). RESULTS: Chronic hypertensive disease is associated with multiparity, age, high body mass index and Nordic ethnicity. After controlling for confounders, chronic hypertensive disease is an independent risk factor for preeclampsia (OR 3.8; 95% CI 3.4-4.3), gestational diabetes (OR 1.8; 95% CI 1.4-2.4) and placental abruption (OR 2.3; 95% CI 1.6-3.4). CONCLUSION: Chronic hypertensive disease is independently associated with an increased incidence of preeclampsia, gestational diabetes and placental abruption.