Antihypertensive Medications for Severe Hypertension in Pregnancy: A Systematic Review and Meta-Analysis

Background: Hypertension in pregnancy causes significant maternal and fetal mortality and morbidity. A comprehensive assessment of the effectiveness of antihypertensive drugs for severe hypertension during pregnancy is needed to make informed decisions in clinical practice. This systematic review aimed to assess the efficacy and safety of antihypertensive drugs in severe hypertension during pregnancy. Methods: A systematic review using the electronic databases MEDLINE (PubMed) and Cochrane Library was performed until August 2021. The risk-of-bias 2 tool was used to assess the risk-of-bias in each study included. Meta-analysis was conducted to assess heterogeneity and to estimate the pooled effects size. Results: Seventeen studies fulfilled the inclusion criteria and 11 were included in the meta-analysis. Nifedipine was estimated to have a low risk in persistent hypertension compared to hydralazine (RR 0.40, 95% CI 0.23-0.71) and labetalol (RR 0.71, 95% CI 0.52-0.97). Dihydralazine was associated with a lower risk of persistent hypertension than ketanserin (RR 5.26, 95% CI 2.01-13.76). No difference was found in the risk of maternal hypotension, maternal and fetal outcomes, and adverse effects between antihypertensive drugs, except for dihydralazine, which was associated with more adverse effects than ketanserin. Conclusions: Several drugs can be used to treat severe hypertension in pregnancy, including oral/sublingual nifedipine, IV/oral labetalol, oral methyldopa, IV hydralazine, IV dihydralazine, IV ketanserin, IV nicardipine, IV urapidil, and IV diazoxide. In addition, nifedipine may be preferred as the first-line agent. There was no difference in the risk of maternal hypotension, maternal and fetal outcomes, and adverse effects between the drugs, except for adverse effects in IV dihydralazine and IV ketanserin.