8Ananth CV, Smulian JC, Demissie K, et al. Placental abruption among singleton and twin births in the United States: risk factor profiles [J]. American Journal of Eoidemiology,2001,153(8):771-778.
9Sheiner E, Shoham Vardi I, Hallak M, et al. Placental abruption in term pregnancies: clinical significance and obstetric risk factors [J]. The Journal of Maternal-Fetal & Neonatal Medicine,2003,13(1):45-49.
10Tikkanen M, Nuutila M, Hiilesmaa V, et al. Clinical presentation and risk factors of placental abruption [J]. Acta Obstetriciaet Gynecologica Scandinavica,2006,85(6):700-705.
