Clinical Presentation and Risk Factors of Placental Abruption

Background: To study the risk factors of placental abruption during the index pregnancy.

Methods: One hundred and ninety-eight women with placental abruption and 396 control women were identified among 46,742 women who delivered at a tertiary referral university hospital between 1997 and 2001. Clinical variables were compared between the groups. Multivariate logistic regression analysis was applied to identify independent risk factors. The clinical manifestations of placental abruption were also studied.

Results: The overall incidence of placental abruption was 0.42%. The independent risk factors were maternal (adjusted OR 1.8; 95% CI 1.1, 2.9) and paternal smoking (2.2; 1.3, 3.6), use of alcohol (2.2; 1.1, 4.4), placenta previa (5.7; 1.4, 23.1), pre-eclampsia (2.7; 1.3, 5.6), and chorioamnionitis (3.3; 1.0, 10.0). Vaginal bleeding (70%), abdominal pain (51%), bloody amniotic fluid (50%), and fetal heart rate abnormalities (69%) were the most common manifestations. Neither bleeding nor pain was present in 19% of the cases. Overall, 59% had preterm labor (OR 12.9; 95% CI 8.3, 19.8), and 91% were delivered by cesarean section (34.7; 20.0, 60.1). Of the newborns, 25% were growth restricted. The perinatal mortality rate was 9.2% (OR 10.1; 95% CI 3.4, 30.1). Retroplacental blood clot was seen by ultrasound in 15% of the cases.

Conclusions: Maternal alcohol consumption and smoking, and smoking by the partner turned out to be independent risk factors for placental abruption. Smoking by both partners multiplied the risk. The liberal use of ultrasound examination contributed little to the management of women with placental abruption.