Ranking the risk factors for cesarean: logistic regression analysis of a nationwide study.

The risk factors that influenced the decision to perform cesarean were ranked in a nationwide census of deliveries conducted in Israel. The study encompassed 22,815 women who gave birth between November 1, 1983 and January 31, 1984 in the 30 maternity departments in the country; 2179 deliveries were by emergency cesarean. Multivariate stepwise logistic regression technique indicated that the most important risk factors affecting the decision were the presentation of the fetus and the presence of a uterine scar, followed in descending order by placenta previa or abruptio placentae, maternal disease, primiparity, low birth weight, twins, and advanced maternal age. The mother's ethnic background and type of hospital played an insignificant role in the decision-making process. The specific statistical method applied in this work permits listing the indicators that constitute risk factors for cesarean and provides the net effect of each factor on the decision-making process.