Women who undergo balloon cervical ripening at home spend less time in the labor and delivery unit and have fewer cesarean deliveries than those who have the induction procedure in a hospital, researchers have found.
The findings, from a meta-analysis of eight previously conducted randomized clinical trials involving 740 women, should spur hospitals to “create and adhere to evidence-based guidelines” for outpatient balloon use, according to the researchers.
“Outpatient balloon cervical ripening is a safe alternative for low-risk patients and has the potential for significant benefits to patients and labor and delivery units,” the authors reported Jan. 6 in Obstetrics and Gynecology.
The rate of labor induction in the United States rose to 29.4% in 2019, the year following publication of the ARRIVE trial of low-risk nulliparous pregnant women, which found that induction at 39 weeks resulted in fewer cesarean deliveries with no difference in neonatal outcomes compared with expectant management, defined as continuing pregnancy until at least 40 weeks 5 days unless induction was medically indicated. Most women require preparation with a balloon-tipped catheter that slowly inflates to stretch and thin out the cervix, a process that can take many hours.
The devices have been shown to be safe, effective, and inexpensive, but the data on outpatient use are limited, according to the researchers. The new study is the “most comprehensive” examination of randomized clinical trials comparing outpatient and inpatient balloon cervical ripening, they say.
The trials included singleton gestations of at least 37 weeks of primarily low-risk patients. Body mass index was slightly lower in the outpatient group, with no differences in maternal age, gestational age at induction, or parity.
Six studies with 571 patients reported on the primary outcome, defined as time from labor unit admission to delivery. The outpatient group had a mean 16.3 hours compared with 23.8 hours for the inpatient group, a difference of 7.24 hours. However, data from three of the studies showed the inpatient group experienced 5.19 hours on average less between balloon expulsion and delivery, potentially due to more frequent adjustments and evaluation for expulsion.
The researchers observed no differences in adverse maternal or neonatal outcomes, and no stillbirths were reported among 378 patients who had the outpatient procedure. Cesarean delivery occurred less often in the outpatient group (21%) versus the inpatient group (27%) (risk ratio, 0.76; 95% confidence interval, 0.59-0.98).
Corresponding author Vincenzo Berghella, MD, director of the Division of Maternal-Fetal Medicine at Jefferson University Hospitals, Philadelphia, called the data “very assuring.” He said, “We knew induction was good in the hospital for many indications. We now know that induction can be started at home and it’s safe.”
Dr. Berghella added that the lower rate of cesarean delivery in the outpatient group likely reflected less use of fetal heart-rate monitoring, which can produce false-positive predictions of fetal compromise.
Still, too few patients have been studied to completely rule out rare adverse events with use of the balloons in the outpatient setting, the researchers acknowledge.
Aaron B. Caughey, MD, PhD, of Oregon Health and Science University, Portland, who was not involved in the study, said current data do not put to rest all safety concerns with the balloons, and it will be vital for health systems to report outcomes as outpatient use of the devices increases.
“Outcomes such as chorioamnionitis and postpartum hemorrhage will be important to have more data on, though there do not appear to be trends from these data,” Dr. Caughey told this news organization. Rarer outcomes, such as cervical injury, placenta abruption, and fetal injury, he added, “will require much larger studies to examine these potential but unlikely risks.”
The authors and Dr. Caughey have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
*Correction, 1/19/22: An earlier version of the headline of this article misstated a study finding. The study found that women who undergo balloon cervical ripening spend less time in the labor and delivery unit than those who have the induction procedure in a hospital.