Hendricks M S, Chow Y H, Bhagavath B, Singh K
Department of Obstetrics and Gynaecology, National University Hospital, Singapore.
J Obstet Gynaecol Res. 1999 Apr;25(2):137-42. doi: 10.1111/j.1447-0756.1999.tb01136.x.
To determine the risk of subsequent occurrence of placenta previa in women with a history of previous cesarean sections and/or spontaneous and induced abortions.
A retrospective analysis of all single gestation deliveries at National University Hospital of Singapore from 1993-1997 was done. Women with placenta previa were identified by clinical or ultrasonographic diagnosis.
Of the 16,169 singleton deliveries, 164 women (1.0%) had placenta previa. Women with placenta previa had a significantly higher incidence of previous cesarean sections (p < 0.001). Among the 164 women with placenta previa, women with 1, 2, and 3 previous cesarean sections had 2.2 (95% CI 1.4, 3.4), 4.1 (95% CI 1.9, 8.8) and 22.4 (95% CI 6.4, 78.3) times increased risk of developing placenta previa respectively. Similarly, women with 2 or more previous abortions had a 2.1 (95% CI 1.2, 3.5) times increased risk of subsequently developing placenta previa.
There is a strong association between previous cesarean section and risk of subsequent development of placenta previa. This risk increased with the number of previous cesarean sections. Increasing frequency of abortions was also found to predispose a woman to placenta previa.
确定有剖宫产史和/或自然流产及人工流产史的女性随后发生前置胎盘的风险。
对新加坡国立大学医院1993年至1997年所有单胎分娩进行回顾性分析。通过临床或超声诊断确定前置胎盘的女性。
在16169例单胎分娩中，164例女性（1.0%）发生前置胎盘。前置胎盘女性既往剖宫产的发生率显著更高（p<0.001）。在164例前置胎盘女性中，既往有1次、2次和3次剖宫产的女性发生前置胎盘的风险分别增加2.2倍（95%可信区间1.4, 3.4）、4.1倍（95%可信区间1.9, 8.8）和22.4倍（95%可信区间6.4, 78.3）。同样，既往有2次或更多次流产的女性随后发生前置胎盘的风险增加2.1倍（95%可信区间1.2, 3.5）。
既往剖宫产与随后发生前置胎盘的风险之间存在密切关联。这种风险随着既往剖宫产次数的增加而增加。流产频率增加也被发现使女性易患前置胎盘。
