Postpartum health risks among women with hypertensive disorders of pregnancy, California 2008-2012

Abstract

Objectives: The aim of this study was to understand the associations between hypertensive disorders of pregnancy (HDP) and postpartum complications throughout the newly defined 12-week postpartum transition.

Study design: We conducted a retrospective cohort study of the associations of HDP (any/subtype) with postpartum complications among 2.5 million California births, 2008-2012. We identified complications from discharge diagnoses from maternal hospital encounters (emergency department visits and readmissions) in the 12 weeks after giving birth. We compared rates of complications, overall and by diagnostic category, between groups defined by HDP. In survival analyses, we calculated the adjusted hazard ratios of postpartum complications associated with HDP. We adjusted for maternal age, race/ethnicity, prepregnancy obesity, chronic diabetes, gestational diabetes, insurance, delivery mode, gestational age and birth outcome (term and size).

Results: Among women with and without HDP, 12.8 and 7.7%, respectively, had a hospital encounter within 12 weeks of giving birth [adjusted hazard ratio 1.5, 95% confidence interval (95% CI): 1.5-1.5]. HDP was associated with increased risk across all major categories of complications: hypertension-related, adjusted hazard ratio 11.8 (95% CI: 11.2-12.3); childbirth-related, 1.4 (1.3-1.4); and other, 1.4 (1.4-1.4). Risk of any complication differed by hypertensive subtype: chronic hypertension with super-imposed preeclampsia, adjusted hazard ratio 1.8 (95% CI: 1.7-1.8); chronic hypertension, 1.6 (1.6-1.7); preeclampsia/eclampsia, 1.3 (1.3-1.4); and gestational hypertension, 1.2 (1.2-1.3). Over a quarter (28.9%) of maternal hospital encounters occurred more than 6 weeks after giving birth; this did not differ substantially by HDP status.

Conclusion: Women with HDP are at an increased risk for virtually all postpartum complications, including those not related to hypertension, and may benefit from enhanced and comprehensive postpartum care.

FIGURE 1

Time-to-first postpartum hospital encounter by hypertensive disorders of pregnancy status (unadjusted). (b) Zoomed in. Vertical lines denote common postpartum milestones: 1 week, 6 weeks and 12 weeks after delivery.

FIGURE 2

Time-to-first postpartum hospital encounter by hypertensive disorders of pregnancy subtype (unadjusted). (b) Zoomed in. Vertical lines denote common postpartum milestones: 1 week, 6 weeks and 12 weeks after delivery.