Safe treatment of severe preeclampsia with nifedipine during labor

According to a new study published today in Hypertension, Journal of the American Heart Association. Women who received the medication were less likely to experience dangerously high blood pressure that required treatment with fast-acting drugs, including intravenous (IV) drugs.

The study looked at whether treatment with nifedipine, a long-acting blood pressure-lowering drug, could lead to labor and delivery can prevent the development of serious blood pressure levels and consequently avoid the need for rapid-acting IV drugs.

According to the American Heart Association, preeclampsia is usually diagnosed after 20 weeks of pregnancy and shows high blood pressure measures with symptoms such as headache, vision changes and swelling of the hands, feet, face or eyes. The diagnosis of preeclampsia with severe symptoms usually includes systolic blood pressure (top number in blood pressure measurement) 160 mm Hg. or above and/or diastolic blood pressure (lower number when measuring blood pressure) 110 mm Hg. or higher and high levels of protein in the urine. It affects up to 8% of pregnancies and increases the risk of stroke, liver or kidney damage, and preterm birth (birth before 40 weeks). Giving birth is the only way to start treatment for preeclampsia, and symptoms usually disappear within a few days after delivery. However, some women continue to need blood pressure medication for six weeks or longer after giving birth.

“We know that lowering very high blood pressure to a safer range will help prevent complications for the mother and the fetus. However, other than rapid-acting intravenous drugs for severe hypertension during pregnancy, there has been no optimal treatment for hypertension during labor and delivery. ” said lead study author Erin M. Cleary, MD, who was a research fellow in fetal medicine at Ohio State University in Columbus, Ohio, when the study was conducted.

Severe high blood pressure also increases the risk of complications such as placental abruption, when the placenta, which provides the developing baby with nutrients and oxygen from the mother, separates from the uterus before the baby is born. This can lead to serious complications for the mother and/or baby.

“Some of these complications can include emergency delivery, blood loss for the mother, and can be life-threatening for both mother and baby,” Cleary said. “Approximately 10% of patients treated for very high blood pressure with a rapid IV can have a rapid drop in blood pressure. If the blood pressure gets too low, too fast, it can lead to other serious complications.”

The study was conducted from June 2020 to April 2022 at Ohio State University Wexner Medical Center in Columbus and included 110 women who were at least 22 weeks pregnant, diagnosed with severe preeclampsia, and who underwent induction of labor. Half of the participants were randomly assigned to take one nifedipine extended-release 30 mg tablet each day until delivery, and the other half of the participants were randomly assigned to take a placebo tablet daily until delivery. Neither the study investigators, the clinical care team, nor the women knew whether they had been assigned to receive nifedipine or a placebo. Participants were followed at hospital discharge, and chart reviews were conducted for 6 weeks postpartum to monitor for any postpartum readmissions along with reasons for readmission.

The researchers also looked at the effects of nifedipine treatment on delivery, when and how long the baby might need care in neonatal intensive care unit (NICU) and other adverse maternal and/or infant outcomes.

The study found:

• 34% of women in the nifedipine group needed therapy for acute hypertension (immediate lowering of blood pressure), compared with 55.1% in the placebo group.
• Among women treated with nifedipine, there were fewer cesarean sections: 20.8% of women in the nifedipine treatment group had a cesarean section compared with 34.7% of women in the placebo group.
• The rate of neonatal admission to the intensive care unit was lower when the mother received nifedipine (29.1%) compared to the placebo group (47.1%).
• Poor infant outcomes, such as a lower Apgar score, low blood sugar, high bilirubin, or need for supplemental oxygen, were not significantly different between the two treatment groups.

However, it is important to note that the number of participants in this study was too small to determine whether the differences in the rates of intensive care and cesarean section may be true or may be due to chance or other factors. The researchers plan to conduct larger studies with more participants to better understand whether these differences are true.

American Heart Association Scientific Statement March 2021 Adverse pregnancy outcomes and cardiovascular disease risk: unique opportunities for cardiovascular disease prevention in womendescribes pregnancy-related complications that increase a woman’s risk of developing cardiovascular disease after childbirth: high blood pressure, gestational diabetes, premature birth, small-for-term birth, pre-eclampsia, pregnancy loss or placental abruption. The statement calls for vigorous primary prevention of cardiovascular disease (CVD), prevention of CVD risk factors during pregnancy, and lifelong surveillance of CVD risk.

Co-authors are Nicholas W. Rachi, DO; K. Grace Patton, MD; Meghana Kudrimotti, BS; Maged M. Konstantin, MD; and Cara M. Rood, MD Author disclosures are listed in the manuscript.