Cesarean delivery: background, trends, and epidemiology.

OBJECTIVE To examine trends in cesarean delivery for the overall population and for women with "no indicated risk" for cesarean section, and to summarize the available literature on "maternal request" cesarean deliveries. FINDINGS Nearly 3 in 10 births were delivered by cesarean section in 2004 (29.1%), the highest rate ever reported in the United States. The overall rate has increased by over 40% since 1996, reflecting two concurrent trends: an increase in the primary rate (14.6% to 20.6%), and a steep decline in the rate of vaginal birth after cesarean (28.3% to 9.2%). There has been a clear increase in primary cesarean delivery without a medical or obstetrical indication, and studies using hospital discharge data or birth certificate data estimate the rate of primary cesarean deliveries with no reported medical or obstetrical indication to be between 3% and 7% of all deliveries to women who had not had a previous cesarean delivery. However, these studies contain no direct information on whether these cesareans were the result of maternal request or because of physician recommendation. There was little data to support the contention that the rise in the cesarean rate was the result of maternal request. CONCLUSION There are no systematic data available on cesarean delivery by "maternal request." However, the rate of primary cesarean delivery is increasing rapidly for women of all ages, races, and medical conditions, as well as for births at all gestational ages. Since a first cesarean section virtually guarantees that subsequent pregnancies will be cesarean deliveries (the repeat cesarean delivery rate is now almost 91%), research is needed on physician practice patterns, maternal attitudes, clinical outcomes for mother and infant (harms, benefits), and clinical and nonclinical factors (institutional, legal, economic) that affect the decision to have a cesarean delivery.