GRAPEVINE, Texas -- Fewer women with hypertensive disorders of pregnancy randomized to receive the loop diuretic, furosemide (Lasix), after delivery experienced consistently elevated post-partum blood pressure compared with women who received placebo, a researcher said here.
Compared to 14% of patients randomized to placebo, 6% of patients randomized to furosemide experienced persistently elevated blood pressure at 7 days after delivery (aRR 0.40, 95% CI 0.20-0.81, P=0.01), reported Joana Lopes Perdigao, MD, of the University of Pennsylvania Perelman School of Medicine in Philadelphia.
Post-partum hypertension can persist in women, can often be severe and accounts for about 30% of readmissions, Perdigao noted in a late-breaking presentation at the Society for Maternal-Fetal Medicine annual meeting.
But scant research exists on post-partum elevated blood pressure in this population, as Perdiago illustrated by citing research that first found that blood pressure can up to 3-6 days postpartum.
"A 1987 study that's as old as me," she quipped.
One theory behind elevated post-partum blood pressure is that there is a "large volume of sodium mobilized into the intravascular compartment in the post-partum period. Loop diuretics have been suggested as methods to accelerate post-partum blood pressure recovery due to their "ability to mobilize sodium and fluid excretions," Perdigao noted.
However, prior studies of loop diuretics have been inconsistent, she said, and limited by small sample size, as well as relying on a one-time blood pressure assessment, not continuous daily outpatient blood pressure monitoring.
This trial examined women with hypertensive disorders of pregnancy, such as gestational hypertension and preeclampsia, who were diagnosed within the first day postpartum after delivery at 20 weeks gestation or higher. They received either 5 days of 20 mg of oral furosemide or placebo, and were sent home with any remaining pills.
Blood pressure measurements were collected up to 14 days post-partum, including inpatient and outpatient blood pressure monitoring through a text-based blood pressure program that gives women a blood pressure cuff on discharge and instructs them to measure their blood pressure twice a day.
The primary outcome was persistently elevated blood pressure at 7 days post-partum, defined as 48 hours of blood pressure still greater than 140/90 mm Hg, as well as the number of days required for blood pressure resolution. Data was adjusted for mode of delivery and randomized by disease severity.
In this intention-to-treat analysis, 384 women were randomized (192 per group). About 75% of women were black, and the rate of cesarean section delivery was significantly higher in the furosemide group, though most baseline characteristics were similar.
Perdigao also noted the median BMI was 35, which was "slightly different than our French colleagues."
While there was a 60% reduction the prevalence of women with elevated blood pressure in the furosemide group versus placebo, there was no difference between groups in days to blood pressure resolution.
However, researchers found a significant difference in time to blood pressure resolution among women with non-severe hypertensive disorders compared with severe hypertensive disorders in the furosemide group (8.5 days vs 10 days, respectively).
Women in the furosemide group had a 40% reduction in the need for additional anti-hypertensive medication versus the placebo group (13% vs 20%, aRR 0.61, P=0.03), although researchers found no difference in hypertension-related readmissions or ER visits.
Perdigao said their results indicate that 13 women would need to be treated with furosemide to prevent one women from having persistent post-partum hypertension, and the authors concluded that "routine use of furosemide should be considered in women with [hypertensive disorders of pregnancy]."
Disclosures
The study was supported by the Maternal and Child Health Research Center.
Perdigao disclosed no relevant relationships with industry.
Primary Source
Society for Maternal-Fetal Medicine
Perdigao JL, et al "Furosemide for Accelerated Recovery of Blood Pressure Postpartum: a randomized placebo controlled trial (FoR BP)" SMFM 2020; Abstract LB4.