Postpartum Diuretics for Hypertensive Disorders of Pregnancy: A Systematic Review and Meta-analysis.

OBJECTIVE To systematically review the use of diuretics to reduce postpartum hypertension among individuals with hypertensive disorders of pregnancy. DATA SOURCES MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials were searched through June 2024 (PROSPERO CRD42021288277). METHODS OF STUDY SELECTION Randomized controlled trials investigating postpartum diuretic use in individuals with hypertensive disorders of pregnancy with 20 or more participants per arm were included. Primary outcomes were hypertension within 2 weeks postpartum and mean systolic or diastolic blood pressure after treatment. Secondary postpartum outcomes included severe maternal morbidity, use of additional antihypertensives, readmission, hypertension at 6 weeks postpartum, and breastfeeding. Risk of bias was assessed with the Cochrane handbook. A random-effects meta-analysis model used the restricted maximum-likelihood estimated treatment effects with relative risk (RR)/mean difference and 95% CIs. TABULATION, INTEGRATION, AND RESULTS Of 469 records reviewed, 10 randomized controlled trials were included (1,815 individuals: 906 intervention, 909 control). Interventions included furosemide (five trials, N=958), torsemide (one trial, N=118), combined furosemide-antihypertensive drug (three trials, N=670), and combined thiazide-angiotensin-converting enzyme inhibitor (one trial, N=67). Seven trials were at high risk of bias. Diuretic use was associated with a reduction in hypertension within 2 weeks postpartum (five trials, N=1,055, pooled RR 0.54, 95% CI, 0.39-0.74; number needed to treat [NNT] 4). There was no difference in mean systolic or diastolic blood pressure after treatment with diuretics; there was also no difference in severe maternal morbidity, readmissions, or any other secondary outcomes. When analysis was restricted to trials at low risk of bias, the reduction in postpartum hypertension was not significant (two trials, N=502, RR 0.62, 95% CI, 0.36-1.09). CONCLUSION Diuretics were associated with a reduction in immediate postpartum hypertension in individuals with hypertensive disorders of pregnancy (NNT 4), although this reduction was not observed when analysis was restricted to trials at low risk of bias. Further studies are needed to assess the role of diuretics in treating postpartum hypertension. SYSTEMATIC REVIEW REGISTRATION PROSPERO, CRD42021288277.