CESAREAN-SECTION - ANALYSIS OF THE EXPERIENCE BEFORE AND AFTER THE NATIONAL CONSENSUS CONFERENCE ON ASPECTS OF CESAREAN BIRTH

Objective: To examine the effect of recommendations to reduce the cesa rean section rate issued by the National Consensus Conference on Aspec ts of Cesarean Birth in 1986 on obstetric practices and to identify cu rrent patient factors that predict cesarean section. Design: Descripti ve retrospective cross-sectional study. Setting: A tertiary care perin atal referral centre and a general teaching hospital with a level 2 nu rsery in Hamilton, Ont. Patients: All patients who gave birth at the t wo hospitals in 1982 (4121 women) and 1990 (4431). Main outcome measur es: Cesarean section rates and indications and predictors of cesarean section. Results: Although a trial of vaginal delivery after cesarean section was offered 93% more often in 1990 than in 1982 (p = 0.0002), the rate of vaginal delivery increased only 2.6%, for a reduction of 8 .7% in the total cesarean section rate and of 15% in the repeat cesare an section rate. The incidence rate and treatment of dystocia did not change. The rate of cesarean section for breech presentation remained unchanged, and fetal distress was rarely confirmed with pH measurement in scalp blood before cesarean section. The most important predictors of cesarean section in 1990 were previous cesarean section and labour induction. For the nulliparous women and the multiparous women with n o previous cesarean section labour induction was the most important pr edictor. Conclusions: The rate at which patients with previous cesarea n section are offered a trial of vaginal delivery has increased signif icantly since 1982; however, the total and repeat cesarean section rat es have not decreased proportionally. Induction of labour is currently the most important correctable predictor of cesarean section. The act ive management of dystocia, efforts to increase the rate of vaginal br eech delivery and appropriate methods to diagnose fetal distress need to be improved; such improvements should reduce the cesarean section r ate further.