The use of loop diuretics in the context of hypertensive disorders of pregnancy: a systematic review and meta-analysis

Aims: Addressing volume expansion may improve the management of hypertension across the pregnancy continuum. We conducted a systematic review to summarize the evidence on the use of loop diuretics in the context of hypertensive disorders during pregnancy and the postpartum period. Methods and results: Medline, Embase, Cochrane library, ClinicalTrials.gov, and Google Scholar were searched for original research articles published up to 29 June 2021. Of the 2801 results screened, 15 studies were included: eight randomized controlled trials, six before–after studies, and one cohort study. Based on random effects meta-analysis of before–after studies, antepartum use of loop diuretics was associated with lower DBP [mean difference −17.73 mmHg, (95% confidence intervals −34.50 to −0.96); I2 = 94%] and lower cardiac output [mean difference −0.75 l/min, (−1.11 to −0.39); I2 = 0%], with no difference in SBP, mean arterial pressure, heart rate, or total peripheral resistance. Meta-analysis of randomized controlled trials revealed that postpartum use of loop diuretics was associated with decreased need for additional antihypertensive patients [relative risk 0.69, (0.50–0.97); I2 = 14%], and an increased duration of hospitalization [mean difference 8.80 h, (4.46–13.14); I2 = 83%], with no difference in the need for antihypertensive therapy at hospital discharge, or persistent postpartum hypertension. Conclusion: Antepartum use of loop diuretics lowered DBP and cardiac output, while their postpartum use reduced the need for additional antihypertensive medications. There was insufficient evidence to suggest a clear benefit. Future studies focusing on women with hypertensive pregnancy disorders who may most likely benefit from loop diuretics are required.