探讨产程中转剖宫产及临产前择期剖宫产对再次妊娠合并前置胎盘患者临床结局的影响。

回顾分析2016年10月至2021年10月在广州医科大学附属第三医院住院分娩的既往单次剖宫产史、本次妊娠诊断合并前置胎盘的658例单胎患者的临床资料，依据前次剖宫产时机将患者分为临产前择期剖宫产组(择期组，505例)及中转剖宫产组(中转组，153例)，追溯前次剖宫产指征，比较两组患者的临床特征及本次妊娠结局。

两组患者的年龄、体重指数、人工流产次数及生殖助孕率等差异无统计学意义；择期组与中转组比较，合并胎盘植入性疾病比例(69.9% vs 55.6%, χ²＝10.858)、术中出血量(<1000 ml：57.6% vs 75.8%，1000～2000 ml：31.7% vs 20.3%，>2000 ml：10.7% vs 3.9%，χ²＝17.466)、输注血制品量(>0且≤400 ml：10.1% vs 11.1%，>400且≤1200 ml：15.4% vs 11.1%，>1200 ml：12.3% vs 5.2%, χ²＝9.083)、转重症监护病房比例(3.2% vs 0)、术后住院时长(5 d vs 4 d，Ζ＝－2.528)、总住院时长(9 d vs 8 d，Ζ＝－2.260)及足月分娩率(32.3% vs 45.1%，χ²＝8.448)，差异均有统计学意义(P<0.05)。

临产前择期剖宫产是再次妊娠发生前置胎盘合并胎盘植入的高危因素，其母儿不良结局发生率高。

To evaluate the effect of the timing of previous cesarean section on outcomes of subsequent pregnancy complicated with placenta previa.

This was a retrospective cohort study. 658 women with placenta previa, who were all singleton pregnancies and had only one previous cesarean section, were analyzed in Third Affiliated Hospital of Guangzhou Medical University from October 2016 to October 2021. According to the timing of the previous cesarean section, the patients were divided into Elective cesarean (EC group) and Intrapartum cesarean (IC group). The two groups′ clinical characteristics and maternal and neonatal outcomes were analyzed.

There were 505 cases in the EC group and 153 cases in the IC group. No significant differences were found in age, BMI, abortion frequency, reproductive-assisted pregnancy rate and distance from the previous cesarean section between the two groups. The rates of placenta accrete spectrum disorders (69.9% vs 55.6%, χ²=10.858), intraoperative hemorrhage volume (<1000ml: 57.6% vs 75.8%, 1000~2000 ml: 31.7% vs 20.3%, >2000 ml: 10.7% vs 3.9%, χ²=17.466), blood transfusion volume (>0 but ≤400 ml: 10.1% vs 11.1%, >400 but ≤1200 ml: 15.4% vs 11.1%, >1200 ml: 12.3% vs 5.2%, χ²=9.083), the rates of ICU occupancy (3.2% vs 0), postoperative hospitalization days (5 vs 4, Ζ=-2.528), total hospitalization days (9 vs 8, Ζ=-2.260) and the term delivery rate (32.3% vs 45.1%, χ²=8.448) between the EC group and the IC group were statistically significant (P<0.05).

Elective caesarean section before labor onset is a high-risk factor for placenta previa complicated with PAS in a subsequent pregnancy, and maternal and neonatal adverse outcomes are higher.