Mittelstaedt C A, Partain C L, Boyce I L, Daniel E B
Radiology. 1979 May;131(2):465-8. doi: 10.1148/131.2.465.
A prospective study was performed on 98 patients to determine the risk of a second trimester placenta praevia remaining until term. The presence and degree of anterior or posterior praevia were scored for each patient. Follow-up data were obtained at delivery on 58 patients. A greater fraction (63.8%) of second trimester praevia was implanted posteriorly. The overall incidence of a second trimester praevia persisting until term was 8.8%.
对98例患者进行了一项前瞻性研究，以确定孕中期前置胎盘持续至足月的风险。对每位患者的前置胎盘（前位或后位）的存在情况和程度进行评分。对58例患者在分娩时获得了随访数据。孕中期后置胎盘的比例更高（63.8%）。孕中期前置胎盘持续至足月的总体发生率为8.8%。
