Reproductive risk factors, Doppler findings, and outcome of affected births in placental abruption: a population-based analysis.

Placental abruption complicates about 1% of all singleton pregnancies and the aim of this study is to assess the reproductive maternal risk factors associated with placental abruption, and the outcome of affected births. We analyze 170 women with singleton pregnancies complicated by placental abruption who gave birth at Kuopio University Hospital from March 1989 to December 1999. The general obstetric population ( n = 22,905) was selected as the reference group and logistic regression analysis was used to identify independent reproductive risk factors. Furthermore, Doppler ultrasonographic results and pregnancy outcome measures in the two groups were also recorded. The incidence of placental abruption was 0.57% in the referral area. Preeclampsia, grand multiparity, velamentous umbilical cord insertion, cigarette smoking, prior fetal demise, advanced maternal age (>35 years), and previous miscarriage were independent risk factors of placental abruption, with adjusted relative risks of 4.39, 3.60, 2.53, 2.46, 2.02, 1.62, and 1.55, respectively. Most cases of placental abruption occur before the onset of labor in low-risk pregnancies and are not predictable with regard to maternal reproductive risk factors. Current antepartum methods of detecting uteroplacental problems, including Doppler ultrasonography, are not effective in prenatal prediction of placental abruption. The outcome of affected births is still poor.