Results of a randomized controlled trial suggest that women with preeclampsia with severe features benefit from treatment with oral nifedipine during labor and delivery.
The study showed that intrapartum administration of extended-release oral nifedipine was safe and reduced the need for acute intravenous (IV) or immediate-release oral hypertension therapy. There was a trend towards fewer caesarean deliveries and less need for neonatal intensive care.
The results suggest that providers “consider initiating long-acting nifedipine every 24 hours in individuals with preeclampsia with severe features undergoing labor induction,” said Erin M. Cleary, MD, of The Ohio State University, Columbus. theheart.org | Cardiology Medscape.
“There is no need to wait for patients to require one or more acute doses [antihypertensive] therapy before starting long-acting nifedipine if they otherwise meet criteria for preeclampsia with severe features,” Cleary said.
The study was published online on October 3 Hypertension.
Clear benefits for mom and baby
Preeclampsia complicates up to 8% of pregnancies and often leads to significant maternal and perinatal morbidity.
“We know that lowering very high blood pressure to a safer range will help prevent maternal and fetal complications. Other than fast-acting, IV drugs for severe hypertension during pregnancy, however, the optimal treatment for hypertension during labor has not been studied,” Cleary explains in a news release.
In a randomized, triple-blind, placebo-controlled trial, researchers evaluated whether treatment with long-acting nifedipine could prevent severe hypertension in women with singleton or twin pregnancies and preeclampsia with severe features, as defined by the American College of Obstetrics and Gynecology criteria.
During induction of labor between 22 and 41 weeks’ gestation, 55 women were assigned 30 mg of oral nifedipine extended-release and 55 received matching placebo administered every 24 hours until delivery.
The primary outcome was administration of one or more doses of acute hypertensive therapy for a blood pressure of at least 160/110 mm Hg that persisted for 10 minutes or longer.
The primary outcome occurred in significantly fewer women in the nifedipine group than in the placebo group (34% vs. 55%; relative risk [RR]0.62; 95% CI, 0.39–0.97; number needed to treat, 4.7).
Fewer women in the nifedipine group than in the placebo group required cesarean delivery, although this difference did not reach statistical significance (21% vs. 35%; RR, 0.60; 95% CI, 0.31–1.15).
There was no difference between the groups in the rate of hypotensive episodes, including symptomatic hypotension requiring phenylephrine as pressure support after neuraxial anesthesia (9.4% vs 8.2%; RR, 1.15; 95% CI, 0.33–4.06) .
After delivery, there was no difference in the rate of persistently severe blood pressure requiring acute therapy and maintenance therapy at the time of discharge home.
Birth weight and small-for-gestational-age delivery rates were similar in both groups. There was a trend towards a lower rate of neonatal intensive care unit admissions in infants born to mothers receiving nifedipine (29% vs. 47%; RR 0.62; 95% CI, 0.37–1.02).
Neonatal composite outcome was also similar in the nifedipine and placebo groups (36% vs. 41%; RR, 0.83; 95% CI, 0.51–1.37). The composite outcome included Apgar score <7 at 5 minutes, hyperbilirubinemia requiring phototherapy, hypoglycemia requiring intravenous therapy or supplemental oxygen therapy after the first 24 hours of life.
“Our findings support a growing trend toward more active management of hypertension in pregnancy with daily maintenance medications,” Cleary and colleagues note in their paper.
“Even in the absence of preeclampsia, new research suggests that pregnant individuals may benefit from initiation and titration of antihypertensive therapy to targets similar to the nonpartum population,” they add.
Potentially practice change
Asked for comment, Vesna Garovic, MD, PhD, with the Mayo Clinic, Rochester, Minn., said this is “an important introductory paper to start a very important conversation about blood pressure treatment targets in preeclampsia.”
Garovic noted that for chronic hypertension in pregnancy, the treatment goal is now blood pressure ≤140/90 mm Hg.
“However, this does not apply to preeclampsia, where relatively high blood pressures, such as 160/110 mm Hg or higher, are still allowed before treatment is considered,” Garovic said. theheart.org | Cardiology Medscape.
“This study shows that once you reach this level, treatment with oral nifedipine should be started and that early initiation of oral nifedipine can optimize blood pressure control and reduce the need for subsequent intravenous therapy, which has good effects on the mother without adversely affecting the baby,” said Garovic .
“This is potentially a practice change,” Garovic added. “But the elephant in the room is why we wait until blood pressure reaches such dangerous levels before starting treatment, and whether starting treatment at blood pressure of 140/90 or higher can prevent blood pressure from reaching these high levels and in women who develop complications that result from severe hypertension.”
The Ohio State University Department of Obstetrics and Gynecology funded the study. Cleary and Garovic have disclosed no relevant financial relationships.
Hypertension. Published online 3 October 2022. Abstract
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