Hill D J, Beischer N A
Aust N Z J Obstet Gynaecol. 1980 Feb;20(1):21-3. doi: 10.1111/j.1479-828x.1980.tb00889.x.
The incidence of placenta praevia praevia in a series in a series of 26,155 patients was 0.9%; in 81 of the 238 patients (34%) there was no antepartum haemorrhage. Placenta praevia was known to be present before delivery in only 12 of the latter group, the condition being diagnosed after vaginal delivery in 17 and at Caesarean section in 52. Approximately 40% of patients with placenta praevia who deliver vaginally have had no antepartum haemorrhage.
在26155例患者的系列研究中，前置胎盘的发生率为0.9%；在238例患者中的81例（34%）没有产前出血。在后者这组中，只有12例在分娩前已知存在前置胎盘，17例在阴道分娩后诊断出该情况，52例在剖宫产时诊断出。约40%经阴道分娩的前置胎盘患者没有产前出血。
