Pregnant women continue to suffer and die unnecessarily from hypertensive disorders, a leading cause of maternal deaths worldwide. Conditions such as pre-eclampsia and eclampsia (PE/E)—which are unique to pregnancy and the immediate postpartum period—are most often characterized by a rapid and unexpected rise in blood pressure. If not diagnosed and treated promptly, they can lead to seizure, stroke, organ failure as well as maternal and perinatal death.
While treatment with magnesium sulfate and drugs that lower blood pressure can reduce death and disability associated with PE/E, the only definitive way to cure this pregnancy complication is with delivery, preferably vaginal, of the baby. Inducing labor is often a critical component of care for women with pre-eclampsia.
Two low-cost methods for labor induction
The World Health Organization recommends two low-cost methods for labor induction for use in low-resource settings, where the majority of PE/E-related mortality and morbidity occurs:
- Oral misoprostol: a tablet that stimulates uterine contractions
- Foley balloon catheter: a fluid-filled balloon device that is inflated in the cervix to help open the cervix in preparation for delivery
The relative risks and benefits of these two medical interventions were unknown until recently, particularly for women requiring labor induction for pre-eclampsia.
To fill this evidence gap, a group of researchers from the University of Liverpool, Gynuity Health Projects and the Government Medical College, Nagpur designed a randomized controlled trial to compare directly the efficacy, safety and acceptability of these two labor induction methods. This study, called the INFORM trial, was conducted in two high-volume public hospitals in Nagpur, India between 2013 and 2015. More than 600 women who required an induction as a result of pre-eclampsia or high blood pressure received either 25 micrograms of oral misoprostol every two hours or a Foley balloon catheter that remained in place for up to 12 hours.
Study shows oral misoprostol is more effective and preferred by women
The INFORM trial found that low-dose oral misoprostol was more effective than a Foley balloon catheter for inducing labor in women with pre-eclampsia or high blood pressure. Women who received oral misoprostol had a quicker labor, were less likely to have a cesarean section delivery and reported higher satisfaction with their labor induction method than those induced by the Foley catheter. There were no differences in adverse effects for mothers or babies between the two groups of women.
Important clinical implications
Misoprostol is widely available globally and is recommended for a variety of obstetric and gynecologic indications. The results from the INFORM study have important implications for clinical practice, especially in situations where the risk of infection is high and the lack of staff means that women cannot be intensely monitored, and could be helpful for developing clinical guidelines and recommendations for labor induction in low-resource settings.
The use of misoprostol for labor induction has been hampered by a lack of tablets of the correct dosage. However, low-dose oral misoprostol tablets are becoming more widely available and—as this study shows—can provide a highly effective, non-invasive, low-cost way to induce labor, even in the most challenging situations.
Read more about the INFORM study in the full open access article published in The Lancet, “Foley catheterisation versus oral misoprostol for induction of labour in hypertensive women in India (INFORM): A multicentre, open-label, randomised controlled trial,” and a related commentary.
Learn more about misoprostol use in maternal health.
Explore the Maternal Health Task Force’s Obstetric Emergency Drills Training Kit, a set of resources for helping to prevent and manage postpartum hemorrhage and pre-eclampsia/eclampsia.