再次剖宫产子宫下段厚度的术前超声检查价值及其高危因素分析

Ultrasonographic value for lower uterine segment thickness in women with previous caesarean section and its risk factors analysis

目的探讨术前超声检查测量再次剖宫产子宫下段厚度的价值及其相关高危因素。方法选择2013年8月-2015年5月在上海市长宁区妇幼保健院行常规产科检查的孕妇，收集有剖宫产史且再次妊娠选择剖宫产的孕妇313例进行回顾性研究。于孕38～39周经腹超声检查测量子宫下段厚度，并与直视下子宫下段的厚度进行比较，观察子宫下段不全破裂的发生情况。根据孕妇的年龄、孕次、既往剖宫产次数、前次剖宫产术后是否感染、前次剖宫产是否临产、两次手术间隔时间和前次新生儿体重进行分组，比较各组孕妇子宫下段的厚度。结果术前经腹超声检查的子宫下段平均厚度显著厚于术中直视下厚度（t=10．169，P〈0．001），两者具有相关性（r=0．682，P=0．000）。术前经腹超声检查子宫下段厚度≥3mm者的子宫下段不全破裂发生率显著低于术前经腹超声检查子宫下段厚度〈3mm者（P〈0．05）。根据不同高危因素分组发现，不同年龄、孕次、既往剖宫产次数，前次剖宫产术后是否感染、前次剖宫产是否临产、两次手术间隔时间不同和前次新生儿体重不同的产妇间子宫下段厚度的差异均无统计学意义（P值均〉O．05）。结论影响剖宫产后再次妊娠时子宫下段厚度的高危因素尚不明确，但术前超声检查监测子宫下段厚度可以作为临床医师判断子宫下段不全破裂的指标。

Objective To evaluate the predictive value of ultrasound in lower uterine segment thickness of women with previous caesarean section and to estimate related risk factors. Methods In this retrospective study, 313 pregnant women who had undergone cesarean section, and took prenatal examination and selected Cesarean section during pregnancy in Shanghai Changning Maternity ＆ Infant Health Hospital from August 2013 to May 2015 were included. The lower uterine segment thickness was measured by abdominal ultrasonography between 38 and 39 weeks＇ gestation and compared with the visual thickness during caesarean section. The occurrence of incomplete rupture of the uterus was observed. All the pregnant women were divided into different groups according to maternal age, gravidity, the number of previous caesarean section, inter-delivery interval and characteristics of the previous caesarean sections including labor status, birth weight and postoperative infections, and the thickness of lower uterine segment of each group were compared. Results The full lower uterine segment thickness observed by transabdominal sonography was significantly greater than that observed during caesarean section （t= 10. 169, P〈0. 001）, and they had a correction （r = 0. 682, P = 0. 000）. A higher incidence of incomplete rupture of uterus in women with a full lower uterine segment thickness 〈 3 mm observed by transabdominal sonography than women with a full lower uterine segment thickness ≥3 mm （P〈0.05）. There were no association between lower uterine segment thickness and the factors including maternal age, gravidity, birth weight, labor at previous cesarean section, interdelivery interval or postoperative infections （all P〉0.05）. Conclusion The risk factors related to lower uterine segment thickness is unclear in pregnant women with repeated caesarean section. Preoperative ultrasound monitoring of the lower uterine segment may be used as an indicator of the incomplete rupture of the uterus.