Decreasing perinatal mortality in placental abruption.

OBJECTIVE: To study perinatal mortality associated with placental abruption. DESIGN: Retrospective population study using the Finnish Hospital Discharge Register and Medical Birth Register data. SETTING: Finland, 1987-2005. POPULATION: Pregnancies with placental abruption and all other births without placental abruption. METHODS: The national Hospital Discharge Register and Medical Birth Register were used to identify all pregnancies with placental abruption. Demographic data and delivery outcomes were collected retrospectively. Perinatal mortality associated with placental abruption was compared with that in other births. Potential risk factors were analysed. MAIN OUTCOME MEASURES: Perinatal mortality in placental abruption. RESULTS: The study consisted of 618 735 women with 1.14 million pregnancies, 4336 of whom had placental abruption. Overall perinatal mortality with abruption was 119 per 1000 births. Placental abruption explained 7% of all perinatal deaths. The mortality among singleton births (125 per 1000) was higher than among multiple births (40 per 1000). The majority of deaths (77%) occurred in utero. Singleton perinatal mortality with abruption decreased from 173 per 1000 in 1987-1990 to 98 per 1000 in 2000-2005 (p < 0.001). In singleton births at <32 gestational weeks, overall perinatal mortality was high (345 per 1000) and was not increased by placental abruption. Prematurity, low birthweight, male fetal sex and maternal smoking were independent risk factors for placental abruption-related perinatal mortality. CONCLUSIONS: Although mortality associated with placental abruption decreased during the study period, placental abruption still remains an important cause of perinatal mortality.