PURPOSE: to verify the contribution of maternal age, parity, twin pregnancy, hypertensive syndrome, and premature rupture of membranes as risk factors for cesarean section. METHODS: after approval by the Ethics in Research Committee of the "Maternidade Professor Monteiro de Morais" - Recife, PE - Brazil, for a case control study, the authors analyzed data from 3919 pregnant women, without two or more prior cesarean sections, who gave birth to alive newborns with gestational age equal to or more than 28 weeks, weighing at least 1,000 g, on cephalic presentation, from September 1, 1999 to August 31, 2000. The case group included women submitted to cesarean section and the control group included women submitted to vaginal delivery. With the data collected from obstetric and neonatal reports, the authors performed multivariate analysis by logistic regression to determine a mathematical equation that associates cesarean probability due to more than one independent variable acting as risk factor, determining odds ratio with a confidence interval of 95% (95% CI), for the variables: maternal age, parity, twin pregnancy, hypertensive syndrome, and premature rupture of membranes. RESULTS: the chances for cesarean section significantly increased 8.3 times in twin pregnancy (OR = 8.3; 95% CI: 3.7-19.1), 3.4 in hypertensive syndrome (OR = 3.4; 95% CI: 2.9-4.0), 1.9 in primiparity (OR = 1.9; 95% CI: 1.8-2.0), 1.5 in maternal age over 34 years (OR = 1.5; 95% CI: 1.2-1.8), and 1.2 in the presence of premature rupture of membranes (OR = 1.2; 95 %CI: 1.0-1.4). CONCLUSIONS: the risk for cesarean section was greater in the presence of premature rupture of membranes, maternal age greater than 34 years, primiparity, hypertensive syndrome, and twin pregnancy.
Cesarean section; Hypertension; Premature rupture of membranes; Twin pregnancy
