超声测量前置胎盘孕妇子宫颈管长度预测阴道出血与早产

应用超声测量前置胎盘孕妇子宫颈管长度,探讨其与阴道出血和早产的关系。方法 将2005年1月至2010年1月在本院产检并分娩的82例前置胎盘孕妇按孕周28～30周、31～33周、34 ～ 36周分为3组,采用超声测量各组孕妇子宫颈管长度,记录3组前置胎盘孕妇子宫颈管长度＞30 mm和≤30 mm例数,观察各组子宫颈管长度＞30 mm和≤30 mm孕妇出现的阴道出血、下腹痛、宫缩临床症状的例数并统计对比早产率、平均分娩孕周、新生儿出生体质量、新生儿窒息率。分别绘制子宫颈管长度预测阴道出血和早产的ROC曲线,计算曲线下面积和最佳临界点。结果 3组前置胎盘孕妇子宫颈管长度＞30 mm和≤30 mm的例数分别为28～30周组:20例、8例,31～33周组:19例、11例,34～36周组:11例、13例。子宫颈管长度≤30 mm的前置胎盘孕妇阴道出血率、早产率均明显高于子宫颈管长度＞30 mm者(28 ～ 30周组:阴道出血率87.50％比20％,早产率75％比15％;31～33周组:阴道出血率72.73％比26.32％,早产率63.64％比21.05％; 34 ～ 36周组:阴道出血率69.23％比27.27％,早产率38.46％比18.18％;均P＜0.05),3组出现下腹痛和官缩临床症状的比例也是子官颈管长度≤30 mm的前置胎盘孕妇高于子宫颈管长度＞30 mm者;3组子宫颈管长度≤30 mm的孕妇平均分娩孕周、新生儿出生体质量则低于子宫颈管长度＞30 mm者(均P＜0.05),新生儿窒息率在28 ～ 30周、31～ 33周组子宫颈管长度≤30 mm的孕妇高于子宫颈管长度＞30mm者(均P＜0.05),而34～36周组的孕妇均未出现新生儿窒息。子宫颈管长度预测阴道出血及早产的ROC曲线下面积分别为73.4％、65.3％,30.5 mm为预测的最佳临界点。结论 超声测量前置胎盘孕妇子宫颈管长度可作为预测阴道出血与早产的一种方法。

Prediction of vaginal bleeding and premature birth by ultrasound-measured cervical length in pregnant women with placenta previa

Objective To measure the cervical length of pregnant women with placenta previa using ultrasound, and to explore the association between cervical length and premature birth or vaginal bleeding. Methods Between January 2005 and January 2010, 82 pregnant women with placenta previa who underwent prenatal examinations and delivery in our hospital were divided into three groups based on gestation weeks 28-30, 31-33 and 34-36. Ultrasound was used to measure the cervical length of pregnant women in three groups. The number of pregnant women with cervical length ＞30 mm or ≤ 30 mm was recorded. Data about vaginal bleeding, abdominal pain, symptomatic uterine contraction, pretmature birth, mean gestation age at delivery, birth weight and neonatal asphyxia rate between pregnant women with cervical length ＞30 mm or ≤30 mm in 3 groups were compared. The ROC curves of vaginal bleeding and premature delivery predicted by cervical length were generated. Area under curve (AUC) and critical point on the ROC were calculated. Results The number of pregnant women with cervical length ＞30 mm or ≤30 mm in three groups were 20, 8 of 28-30 weeks group, 19, 11 of 31-33 weeks group, 11, 13 of 34-36 weeks group respectively. Women with cervical length ≤30 mm were more likely to have vaginal bleeding, premature birth 28-30 weeks group: 87.5％ vs 20％ for vaginal bleeding, 75％ vs 15％ for premature birth; 31-33weeks group: 72.73％ vs 26.32％ for vaginal bleeding, 63.64％ vs 21.05％ for premature birth; 34-36 weeks group: 69.23％ vs 27.27％ for vaginal bleeding, 38.46％ vs 18.18％ for premature birth; all P＜0.05]. The ratio of abdominal pain and symptomatic uterine contraction in pregnant women with cervical length ≤30 mm as compared to those with cervical length ＞30 mm. The mean gestation age and birth weight were lower in pregnant women with cervical length ≤ 30 mm than those in women with cervical length ＞30 mm among three groups (all P＜0.05). In 28-30 and 31-33 weeks groups, the rates of neonatal asphyxia appeared higher in pregnant women with cervical length ≤30 mum as compared to those with cervical length ＞30 mum (all P＜0.05). No neonatal asphyxia was found in 34-36 weeks group. The AUC for vaginal bleeding and premature delivery predicted by cervical length were 73.4％ and 65.3％, with 30.5 mm being the critical point for prediction. Conclusion Measurement of cervical length by using ultrasound can be considered as a method to predict premature birth and vaginal bleeding in pregnant women with placenta previa.