Study finds furosemide fails to lower postpartum hypertension risk

Study finds furosemide fails to lower postpartum hypertension risk | Image Credit: © CasanoWa Stutio - © CasanoWa Stutio - stock.adobe.com.

There is insufficient evidence to conclude furosemide reduces the risk of de novo postpartum hypertension (dnPPHTN), according to a recent study published in the American Journal of Obstetrics & Gynecology.¹

Hypertensive disorders of pregnancy (HDP) are a leading cause of maternal death, with 70% of mortalities linked to hypertension occurring after birth. Normotensive antepartum has been estimated in 33% to 69% of patients with postpartum preeclampsia.²

Severe maternal morbidity (SMM) risk is increased among patients with dnPPHTN, defined as high blood pressure (BP) after delivery in normotensive birthing people.¹ Additionally, no antenatal HDP has been reported in 78% of birthing people diagnosed with eclampsia. However, according to researchers, “investigations of postpartum hypertension are limited.”

Data has indicated a reduced need for antihypertensive therapy and a faster normalization of BP through the use of oral loop diuretics after delivery. Therefore, investigators conducted a clinical trial to assess the impact of this therapy toward reducing hypertensive episodes in patients with dnPPHTN.

Participants included pregnant patients in the Columbia University Irving Medical Center Labor and Delivery Unit with no antenatal diagnosis of hypertension, no administration of magnesium sulfate for seizure prophylaxis by delivery, and high risk of developing dnPPHTN. Exclusion criteria included contraindication to diuretic therapy and diuretic use within 2 weeks before delivery.

Risk factors of dnPPHTN were based on American College of Obstetricians and Gynecologists criteria. Participants were assigned 1:1 to receive either 20-mg oral furosemide (Lasix) once per day for 5 days or matching placebo. Treatment began within 8 hours following delivery.

A postpartum nurse administered the study medication, and BP measurements were performed every 6 hours. A voiding hat was used to measure urine output and participants maintained a voiding log until discharge. Trained clinical team members used the pitting edema scale and figure-of-eight girth measurements to determine lower extremity edema.

BP measurements were performed by participants in both groups twice per day for 6 weeks after delivery. Routine postpartum care was provided for all participants.

Mean arterial pressure (MAP) was reported as the primary outcome, measured as an average in the 24 hours before discharge or before antihypertensive initiation. Secondary outcomes included rates of dnPPHTN and preeclampsia, percentage of elevated BPs, magnesium sulfate administration rates, time to discharge, and hypertension-related SMM rates.

There were 82 participants included in the final analysis, with 41 in each group. A median 5 doses of the study drug were completed, with 27% of the furosemide group and 15% of the placebo group having missing adherence survey data. Tolerance was reported in 82% and 93%, respectively, and adverse events were rare.

Mean MAP did not significantly differ in the 24 hours before discharge between groups, at 88.9±7.4 mm Hg in the furosemide group vs 86.8±7.1 mm Hg in the placebo group. This indicated an absolute difference of 2.1 mm Hg.

Ten percent of participants developed dnPPHTN. However, dnPPHTN, antihypertensive therapy initiation, and SMM rates did not significantly differ between groups.

A higher median percentage of elevated BP at discharge was reported in the furosemide group, at 4% vs 0% in the placebo group. These rates did not differ at 2 to 6 weeks postpartum, nor did other secondary maternal outcomes differ between groups.

These results highlighted the need for close monitoring for severe hypertension in other maternal morbidity in the first 2 weeks postpartum. Investigators concluded “There is insufficient evidence to suggest that furosemide reduces mean MAP in the 24 hours before discharge from delivery hospitalization.”

References

1. Emeruwa UN, Azad H, Ona S, et al. Lasix for the prevention of de novo postpartum hypertension: a randomized placebo-controlled trial (LAPP Trial). Am J Obstet Gynecol. 2025;232:125.e1-21. doi:10.1016/j.ajog.2024.04.016
2. Goel A, Maski MR, Bajracharya S, et al. Epidemiology and mechanisms of de novo and persistent hypertension in the postpartum period. Circulation. 2015;132(18):1726-33. doi: 10.1161/CIRCULATIONAHA.115.015721