Thrombophilic risk factors for placental stillbirth
To define the characteristics of placental stillbirth and the possible contribution of thrombophilic risk factors.A prospective cohort study was performed. Women diagnosed with antenatal stillbirth (>20 weeks) of singleton pregnancies between 2006 and 2008 were referred postpartum for evaluation. Maternal risk factors, fetal, placental and cord abnormalities, and a detailed thrombophilia screening, including inherited and acquired thrombophilia, were evaluated. Fetal autopsy and placental pathology were encouraged. Placental stillbirth was defined as death of a normally-formed fetus with evidence of intrauterine fetal growth restriction, oligohydramnios, placental abruption and/or histological evidence of placental contribution to fetal death. Pregnancy characteristics and thrombophilia profiles were compared between placental and non-placental stillbirth cases.Sixty-seven women with stillbirth comprised the study group. Placental stillbirth was evident in 33/67 (49.3%). Significantly more women with placental stillbirth were nulliparous, when compared with non-placental stillbirth women (21/33 vs. 9/34, p=0.002). Mean gestational age was lower for placental, compared with non-placental stillbirth (31.1 ± 6.1 weeks vs. 33.9 ± 4.8 weeks, p=0.04), as was birth weight. Thirty-six of the 67 women (53.7%) tested positive for at least one thrombophilia. The prevalence of maternal thrombophilia was higher for placental stillbirth women (63.6%), and even higher (69.6%) for women after preterm (<37 weeks) placental stillbirth. Factor V Leiden and/or prothrombin G20210A mutation were much more prevalent in placental versus non-placental stillbirth women (OR 3.06, 95% CI 1.07-8.7).Placental stillbirth comprises a unique subgroup with specific maternal characteristics. Maternal thrombophilia is highly prevalent, especially in preterm placental stillbirth. This may have implications for the management strategy in future pregnancies in this subgroup.