Nielsen T F, Hagberg H, Ljungblad U
Department of Obstetrics and Gynecology, Central Hospital, Borås, Sweden.
Gynecol Obstet Invest. 1989;27(2):88-90. doi: 10.1159/000293625.
A prospective study was conducted to determine the risk of placenta previa and unexplained antepartum hemorrhage after a previous cesarean section (CS). Of a total of 24,644 patients, 81 (0.33%) had a placenta previa which demanded abdominal delivery. The risk of placenta previa was 0.25% with an unscarred uterus and 1.22% in patients with one or more previous CS (the difference was statistically significant p less than 0.001). The corresponding figures for unexplained antepartum hemorrhage were 0.40% and 3.81%, respectively (p less than 0.001). Patients presenting with a placenta previa and a scarred uterus had a 16% risk of undergoing cesarean hysterectomy because of placenta accreta and severe hemorrhage compared to 3.6% in patients with placenta previa and an unscarred uterus. In conclusion, cesarean deliveries predispose to placenta previa, placenta accreta and antepartum hemorrhage during subsequent pregnancies. This relationship has to be considered in the cost-benefit equation for decision of route of delivery.
进行了一项前瞻性研究，以确定既往剖宫产术后前置胎盘和不明原因产前出血的风险。在总共24644例患者中，81例（0.33%）发生前置胎盘，需要经腹分娩。子宫无瘢痕者前置胎盘的风险为0.25%，有一次或多次既往剖宫产史的患者为1.22%（差异有统计学意义，p<0.001）。不明原因产前出血的相应数字分别为0.40%和3.81%（p<0.001）。与子宫无瘢痕的前置胎盘患者相比，有前置胎盘且子宫有瘢痕的患者因胎盘植入和严重出血而接受剖宫产子宫切除术的风险为16%，而子宫无瘢痕的前置胎盘患者为3.6%。总之，剖宫产分娩易导致后续妊娠发生前置胎盘、胎盘植入和产前出血。在决定分娩方式的成本效益方程中必须考虑这种关系。
