Is use of multiple antihypertensive agents to achieve blood pressure control associated with adverse pregnancy outcomes?

OBJECTIVE: We assessed whether requiring >1 medication for blood pressure control is associated with adverse pregnancy outcomes. STUDY DESIGN: Retrospective cohort of 974 singletons with chronic hypertension at a tertiary care center. Subjects on >1 antihypertensive agent were compared with those on one agent <20 weeks gestational age with results stratified by average blood pressure (< 140/90 and >= 140/90 mm Hg) from prenatal visits. The primary maternal outcome was preeclampsia; the primary neonatal outcome was small for gestational age (< 10th percentile). RESULT: Among women with blood pressure >= 140/90 mm Hg, women on multiple agents had the greatest risk of preeclampsia, severe preeclampsia, antenatal admissions to rule out preeclampsia, preterm birth < 35 weeks and composite neonatal adverse outcomes. CONCLUSION: Compared with use of a single agent when blood pressure is >= 140/90 mm Hg, use of multiple agents increases adverse risks, while no such finding exists when blood pressure is controlled below 140/90 mm Hg.