Severe pre-eclampsia treated safely with nifedipine during labour, delivery

Women with severe pre-eclampsia (severe high blood pressure) during pregnancy may be treated with extended-release nifedipine, a blood pressure-lowering medicine, daily during the labour and delivery process, according to new research published in Hypertension, an American Heart Association journal.

Women treated with the medicine were less likely to experience dangerously high blood pressure that would require treatment with fast-acting medicines including intravenous (IV) medications.

The study examined whether treatment with nifedipine, an extended-release blood pressure-lowering medication, leading up to labour and delivery may prevent severe blood pressure levels from developing, and, as a result, avoid the need to administer fast-acting IV medications.

According to the American Heart Association, pre-eclampsia is typically diagnosed after 20 weeks of pregnancy and indicates high blood pressure measures with symptoms such as headaches, vision changes and swelling of the hands, feet, face or eyes.

A diagnosis of pre-eclampsia with severe features typically includes systolic blood pressure (the top number in a blood pressure measurement) of 160 mm Hg or higher and/or diastolic blood pressure (the lower number in a blood pressure measurement) of 110 mm Hg or higher and high protein levels in the urine.

It affects up to eight per cent of pregnancies and increases the risk of stroke, liver or kidney damage and pre-term delivery (delivery before 40 weeks).

Delivery of the baby is the only way to start to cure pre-eclampsia, and symptoms usually go away within days of delivery. However, some women continue to need blood pressure medication for six weeks after delivery or longer.

Severe high blood pressure also raises the risk for complications such as placental abruption, where the placenta, which supplies the baby developing in the uterus with nutrients and oxygen from the mother, detaches from the uterus before the baby is born. This may lead to serious complications for the mother and/or the baby.

The researchers also examined the impact of nifedipine treatment on delivery, if and how long the baby may have needed care in the neonatal intensive care unit (NICU) and other adverse outcomes for the mother and/or baby.

The study found:
•34 per cent of women in the nifedipine group needed acute hypertension therapy (immediate reduction in blood pressure) compared to 55.1 per cent of those in the placebo group.

•There were fewer Cesarean deliveries among the women treated with nifedipine: 20.8 per cent of women in the nifedipine treatment group had a Cesarean section, compared to 34.7 per cent of women in the placebo group.
•The rate of NICU admission for the newborns was lower if the mother was treated with nifedipine (29.1 per cent) compared to the placebo group (47.1 per cent).