应用阴道B超观察临产前宫颈的变化

目的探讨应用阴道Ｂ超,观察临产前宫颈变化对预测分娩结局的临床价值。方法对８３例单胎足月分娩的初产妇自妊娠３６周起,应用阴道Ｂ超测量宫颈长度、宽度及颈管直径,每周１次至临产前。观察以上指标与孕周及距临产时间的关系。按分娩方式分为两组,阴道分娩组５２例,剖宫产组３１例。比较两组间宫颈变化及临产所需时间的差异。结果自孕３６周至临产,宫颈长度逐渐缩小,而颈管直径逐渐增大,与孕周呈明显的相关关系（ｒ＝－０．３７,Ｐ＜０．００００１;ｒ＝０．１６,Ｐ＝０．００２）。距临产时间与宫颈长度和颈管直径呈明显的相关关系（ｒ＝０．３２,Ｐ＜０．００００１;ｒ＝－０．１９,Ｐ＝０．０２）。两组的宫颈长度及距临产所需时间比较,差异无显著性（Ｐ＞０．０５）。在临产前２～３周,宫颈长度＞３．５ｃｍ者,剖宫产率明显大于宫颈长度≤３．５ｃｍ者。结论阴道Ｂ超可以准确地测量宫颈长度、宽度及颈管直径。临产前测量宫颈长度可反映宫颈的成熟状况,并对产程进展和分娩结局有一定的预测意义。

Transvaginal ultrasound assessment of cervical changes before onset of labor

OBJECTIVE: To study the clinical value of cervical measurement by transvaginal ultrasound after 36 weeks of gestation. METHODS: Eighty three normal nulliparous woman were studied from 36 weeks of gestation until delivery prospectivelly. Transvaginal ultrasound examinations were performed and cervical length (CL), cervical width (CW) and the diameter of cervical canal were measured weekly. 52 cases were delivered naturelly and 31 cases by cesarean sections (CS). RESULTS: From 36 weeks of gestation until delivery, there was a significant correlation between gestation age (GA) and CL and the diameter of cervical canal (r = -0.37, P < 0.00001; r = 0.16, P = 0.002). The time from examination to initiation of labor was significantly correlated with CL and the diameter of cervical canal (r = 0.32, P < 0.00001; r = -0.19, P = 0.02). The regressive formulas were CL (cm) = 13.77 - 0.27 x GA, the time to beginning of labor (week) = 0.64 + 0.54 x CL (cm). The cases with CL > or = 3.5 cm at 2-3 weeks before labor had a significant higher CS rate than those with CL < or = 3.5 cm (P = 0.002). CONCLUSIONS: Transvaginal ultrasonographic measurement of CL, CW and the diameter of cervical canal could reflect the maturity of cervix accurately. It could be used as predictors of labor course and outcome of delivery.