Factors Associated with the Recent Increasing Cesarean Delivery Rate at a Japanese Perinatal Center

Objective. We examined which specific factors contributed to the increase in Cesarean delivery rate at our hospital over a 10-year period. Methods. From January 2002 to December 2012, data on the Japanese singleton deliveries at ≥22-week gestation managed at Japanese Red Cross Katsushika Maternity Hospital were collected. Potential factors associated with the increasing Cesarean delivery rate were selected according to previous studies. In this study, the incidences of intrauterine fetal demise, umbilical artery pH 7.1, and severe perineal laceration were calculated for each year. Results. The Cesarean delivery rate at our institution increased significantly during the study period (17.3% in 2002 versus 23.4% in 2012, ). During the study period, the Cesarean delivery rates in the cases of nulliparity, preterm delivery, low birth weight ( 2,500？g), previous Cesarean deliveries and breech presentation were increased significantly. The incidence of intrauterine fetal demise and low umbilical artery pH was significantly decreased, and a negative correlation was found between the Cesarean delivery rate and the incidence of low umbilical artery pH for each year ( , ). Conclusion. At our institute, the neonatal outcomes seemed to be improved associated with the increased Cesarean delivery rate between 2002 and 2012. 1. Introduction Recently, the Cesarean delivery rate has been reported to be steadily increased in the United States [1–3]. Approximately, one-third of births in the United States are now via Cesarean delivery. The increase has been observed to be among women of all ages and race/ethnicities, in every state, and across all gestational ages. Many theories have been proffered to explain this trend, including a decrease in vaginal births after Cesarean delivery (VBAC), decreased vaginal births of breech presentation, and increased prevalence of high risk pregnancies such as advanced maternal age and some subjective indications during labor such as nonreassuring fetal status and arrest of dilation [1, 2]. Although Cesarean delivery rates that are too low are associated with increased adverse events, Cesarean delivery rates higher than the risk-adjusted expected rate for an institution have not been shown to improve maternal or neonatal outcomes, but they do add cost and unnecessary intervention [4]. Therefore, the examination of Cesarean delivery rate concerning perinatal outcomes is very important for obstetricians. To date, however, there have not been sufficient observations concerning the Cesarean delivery rate in Japanese populations. In this