Treating Mild Chronic Hypertension During Pregnancy

Abstract

OBJECTIVE: To assess the cost effectiveness of targeting a blood pressure of less than 140/90 mm Hg compared with 160/105 mm Hg. METHODS: A decision-analytic model was constructed to compare the treatment of chronic hypertension in pregnancy at mild-range blood pressures (140/90 mm Hg) with the treatment of chronic hypertension before 20 weeks of gestation at severe-range blood pressures (160/105 mm Hg) in a theoretical cohort of 180,000 patients with mild chronic hypertension. Probabilities, costs, and utilities were derived from literature and varied in sensitivity analyses. Primary outcomes included incremental cost per quality-adjusted life-year (QALY), cases of preeclampsia, preeclampsia with severe features, severe maternal morbidity (SMM), preterm birth, maternal death, neonatal death, and neurodevelopmental delay. The cost-effectiveness threshold was $100,000 per QALY. RESULTS: Treating chronic hypertension in a population of 180,000 pregnant persons at mild-range blood pressures, compared with severe-range blood pressures, resulted in 14,177 fewer cases of preeclampsia (43,953 vs 58,130), 11,835 of which were cases of preeclampsia with severe features (40,530 vs 52,365). This led to 817 fewer cases of SMM (4,375 vs 5,192), and 18 fewer cases of maternal death (102 vs 120). Treating at a lower threshold also resulted in 8,078 fewer cases of preterm birth (22,000 vs 30,078), which led to 26 fewer neonatal deaths (276 vs 302) and 157 fewer cases of neurodevelopmental delay (661 vs 818). Overall, treating chronic hypertension at a lower threshold was a dominant strategy that resulted in decreased costs of $600 million and increased effectiveness of 12,852 QALYs. CONCLUSION: Treating chronic hypertension at a threshold of mild-range blood pressures is a dominant (lower costs, better outcomes) and cost-effective strategy that results in fewer neonatal and maternal deaths compared with the standard treatment of treating at severe range blood pressures.