Abstract
Objective. To identify risk factors for forceps delivery during first pregnancy. Materials and methods. A retrospective case–control study was carried out in a tertiary maternity ward between January 2001 and December 2003. A total of 582 nulliparous women, with full-term (>37 weeks gestation), singleton, cephalic pregnancies, who delivered by the vaginal route with or without instrumental assistance were evaluated. Results. The strongest risk factors for forceps delivery were birth weight greater than 4000 g (OR: 6.5; 95% CI: 1.6, 26.9), the occiput posterior position of the fetal head (OR: 5.8; 95% CI: 2.5, 13.8), and epidural analgesia (OR: 7.7; 95% CI: 4.1, 14.7). Other significant risk factors for forceps delivery were age over 35 years (OR: 2.4; 95% CI: 1.1, 5.1), induction of labor (OR: 2.1; 95% CI: 1.4, 3.1), first stage of labor longer than 420 min (OR: 2.3, 95% CI: 1.3,4.2), and a prolonged second stage of labor (OR: 1.6, 95% CI: 1.1, 2.4). Conclusion. Age over 35 years and induction of labor are risk factors for forceps delivery at admission. Epidural use, fetal head in occiput posterior position, and birth weight >4000 g are strong intrapartum risk factors for instrumental delivery in nulliparous women.