Pregnant women whose labor stalls while in the active phase of childbirth can reduce health risks to themselves and their infants by waiting out the delivery process for an extra two hours, according to a new study by researchers at the University of California, San Francisco.
By doing so, obstetricians could eliminate more than 130,000 cesarean deliveries – the more dangerous and expensive surgical approach – per year in the United States, the researchers conclude. The study examined the health outcomes of 1,014 pregnancies that involved active-phase arrest – two or more hours without cervical dilation during active labor – and found that one-third of the women achieved a normal delivery without harm to themselves or their child, with the rest proceeding with a cesarean delivery.
The findings appear in the November, 2008 issue of “Obstetrics and Gynecology,” the official journal of the American College of Obstetricians and Gynecologists (ACOG).
While ACOG already recommends waiting at least two hours with adequate contractions in the setting of no progress in active labor, it is routine practice in many clinical settings to proceed with a cesarean for “lack of progress” before those ACOG criteria have been met, according to Aaron Caughey, MD, PhD, an associate professor in the UCSF Department of Obstetrics, Gynecology and Reproductive Sciences, Division of Maternal-Fetal Medicine, and senior author on the paper.
“One third of all first-time cesareans are performed due to active-phase arrest during labor, which contributes to approximately 400,000 surgical births per year,” said Caughey, who is affiliated with the UCSF National Center of Excellence in Women’s Health. “In our study, we found that just by being patient, one third of those women could have avoided the more dangerous and costly surgical approach.”
The cesarean delivery rate reached an all-time high in 2006 of 31.1 percent of all deliveries, according to the UCSF study. Arrest in the active phase of labor has been previously shown to raise the risk of cesarean delivery between four- and six-fold.
“Cesarean delivery is associated with significantly increased risk of maternal hemorrhage, requiring a blood transfusion, and postpartum infection,” Caughey said. “After a cesarean, women also have a higher risk in future pregnancies of experiencing abnormal placental location, surgical complications, and uterine rupture.”
The ten-year study identified all women who experienced what is known as active-phase arrest during their delivery at UCSF from 1991 to 2001. The study only included women with live, singleton deliveries who were delivered full-term.
The researchers examined maternal outcomes such as maternal infection, endomyometritis, postpartum hemorrhage and the need for blood transfusions. It also examined the infant’s Apgar score, rates of infection and frequency of admission to the neonatal intensive care unit, among other health indicators.
The study found an increased risk of maternal health complications in the group that underwent cesarean deliveries, including postpartum hemorrhage, severe postpartum hemorrhage and infections such as chorioamnionitis and endomyometritis, but found no significant difference in the health outcomes of the infants.
It concluded that efforts to continue with a normal delivery can reduce the maternal risks associated with cesarean delivery, without a significant difference in the health risk to the infant.
“Given the extensive data on the risk of cesarean deliveries, both during the procedure and for later births, prevention of the first cesarean delivery should be given high priority,” Caughey said.
Co-authors on the paper were Dana E.M. Henry, MD; Yvonne W. Cheng, MD, MPH; Brian L. Shaffer, MD; Anjali J. Kaimal, MD; and Katherine Bianco, MD, all from the UCSF Department of Obstetrics, Gynecology and Reproductive Sciences, Division of Maternal-Fetal Medicine.
Funding for these studies came from research funds from the National Institutes of Health for Henry and Kaimal. Caughey is supported by a National Institute of Child Health and Human Development grant and the Robert Wood Johnson Foundation. The authors have no potential conflicts of interest to disclose.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. For further information, please visit