低置胎盘的分娩方式探讨

The delivery mode of pregnancies complicated with low-lying placenta and marginal placenta previa

目的:探讨低置胎盘的合理分娩方式。方法:选取2012年1月1日至2014年4月30日在我院分娩的单胎头位低置胎盘产妇650例。按是否试产将患者分为试产组和选择性剖宫产组;按分娩前最后一次超声胎盘下缘距离宫颈内口的距离将患者分为低置胎盘1组(下缘距内口≥0mm但<20mm)、低置胎盘2组(下缘距内口≥20mm但<40mm)和低置胎盘3组(下缘距内口≥40mm但<70mm)。分析患者的阴道试产成功率、试产失败原因、产后出血量及分娩期并发症。结果:(1)试产组的试产总成功率为82.64%,低置胎盘1、2、3组的阴道试产成功率分别为62.5%、82.61%和84.65%,其中因产前出血而改行剖宫产的风险分别为31.25%、8.7%和1.49%;(2)低置胎盘1组患者中阴道试产和选择性剖宫产的产后出血量无显著差异[(590.94±382.79)ml vs(465.68±367.83)ml];低置胎盘2组和3组中阴道试产的产后出血量明显少于剖宫产组[(267.17±104.47)ml vs(388.10±205.61)ml,P<0.0001]及[(293.00±263.731)ml vs(348.59±98.68)ml,P<0.0001]。结论:胎盘下缘距宫颈内口≥20mm不应作为孕妇选择性剖宫产的手术指征。

Objective： To discuss the delivery mode of pregnancies complicated with low-lying placenta and marginal placenta previa. Method： A total of 650 singleton pregnancies with placenta previa delivered in Shanghai First Maternity and Infant Hospital from Jan 1st 2012 to Apr 30 th 2014 were studied. All cases were categorized into three groups according to the placental edge from the internal os diagnosed on sonography： Group 1（ the placental edge within 20 mm from the internal os）; Group 2（ the placental edge between 20 ~ 40 mm from the internal os）; Group 3（ the placental edge between 40 ~ 70 mm from the internal os）. The success rate of vaginal birth,postpartum hemorrhage rate and other maternal and perinatal outcomes were analyzed. Results：（ 1） The overall success rate of vaginal birth was 82. 64%,while the rate in three subgroups were 62. 5%,82. 61% and 84. 65% respectively. The rate of an emergent cesarean section for antepartum hemorrhage were 31. 25%,8. 7% and 1. 49% in three subgroups respectively.（ 2） In group 1,the incidence of postpartum hemorrhage did not significantly differ between elective cesarean delivery and vaginal delivery[（ 590. 94 ± 382. 79） ml vs（ 465. 68 ± 367. 83） ml]. In group 2 and group 3,postpartum blood loss was more severe in those delivered with cesarean section than with vaginal birth[（ 267. 17 ± 104. 47） ml vs（ 388.10 ± 205. 61） ml;（ 293. 00 ± 263. 731） ml vs（ 348. 59 ± 98. 68） ml,P 〈0. 0001]. Conclusion：The placental edge more than 20 mm from the internal os is not an indication for cesarean delivery.