The Agency for Healthcare Research and Quality (AHRQ)
Research Activities Online Newsletter, October 2003
The rate of cesarean deliveries in the United States declined from 1989 to 1996, but it increased after 1996 and reached a new high of 24 percent in 2001. A higher cesarean delivery rate is not necessarily associated with better perinatal outcomes. In fact, this rate could be lowered without an increase in infant mortality, concludes a study supported in part by the Agency for Healthcare Research and Quality (HS10795).
According to the researchers who conducted the study, obstetricians who performed a low, medium, and high rate of cesarean deliveries had comparable perinatal mortality rates. Also, higher cesarean delivery rates for low or very low birthweight infants did not improve their survival. The rate of uterine rupture was 44 percent lower in patients attended by physicians who performed a lower rate of c-sections compared with medium-rate physicians, partly because fewer women in the low-rate group had a prior cesarean delivery. However, infants delivered by low-rate doctors had a 53 percent greater risk of intracranial injury compared with those delivered by medium- or high-rate physicians. More women labored before cesarean delivery in the low-rate group, and low-rate physicians probably allowed more prolonged labor.
These results are consistent with the conclusions of some studies which found that long labor contributes to the risk of intracranial injury, says Tong Li, Ph.D., of the University of Medicine and Dentistry of New Jersey. Dr. Li and colleagues linked vital birth certificate data to corresponding hospital discharge records on 171,295 singleton births in New Jersey in 1996 and 1997. They divided obstetricians into three groups based on their cesarean delivery rates during the study period: low (less than 18 percent of deliveries), medium (18-27 percent), and high (more than 27 percent). They compared group rates of perinatal mortality, birth injury, and uterine rupture, after adjusting for differences in patient risks.
See "Physician cesarean delivery rates and risk-adjusted perinatal outcomes," by Dr. Li, George G. Rhoads, M.D., M.P.H., John Smulian, M.D., M.P.H., and others in the June 2003 Obstetrics & Gynecology 101(6), pp. 1204-1212.