Reproductive risk factors of fetal asphyxia at delivery: a population based analysis.

To investigate reproductive maternal risk factors of intrapartum fetal asphyxia, we analyzed 556 women with singleton pregnancies complicated by intrapartum fetal asphyxia who gave birth at Kuopio University Hospital from January 1990 to December 1998. The general obstetric population (N=21746) was selected as the reference group and logistic regression analysis was used to identify independent reproductive risk factors. The incidence of intrapartum fetal asphyxia was 2.5%. Placental abruption, primiparity, alcohol use during pregnancy, low birth weight, preeclampsia, male fetuses, and small-for-gestational age births were independent risk factors of intrapartum asphyxia, with adjusted relative risks of 3.74, 3.10, 1.75, 1.57, 1.49, 1.48 and 1.33, respectively. Most cases of intrapartum fetal asphyxia occur in low-risk pregnancies and, therefore, risk screening in antenatal care cannot accurately predict which women will eventually need emergency care for fetal asphyxia.