【摘要】目的探讨妊娠晚期不同孕周脐动脉血流图S/D 值正常与异常的分界值。方法应用胎儿脐血流检测仪监测妊娠晚期脐动脉血流 1 752 例，计算各孕周S/D的平均值和标准差，分析正常与异常的界限值，设定值以妊娠36周S/D≥3.0为异常值，每小于1孕周，此值增加0.1，每大于1孕周，此值降低0.1。结果各孕周间的异常检出率比较稳定，异常检出率为6.8%。结论应用S/D异常设定值，比单纯以S/D≥3.0或以平均数、标准差计算作为异常值，更有利于临床工作。

    【关键词】脐动脉血流图；异常值

    Investigate the S/D unusual boundary value in navel artery blood flow picture

    ZHANG ZaiqingLI Fasheng

    The Second People's Hospital of Shenzhen518035

    【Abstract】ObjectiveTo investigate the S/D unusual boundary value in navel artery blood flow picture.Methods1752 cases of the navel arteries blood flow in later period gestation were detected by fetus' navel blood flow detector.The average value and standard deviation of S/D of every pregnant weeks were calculated and the unusually demarcation line value were analysed.S/D≥3.0 was regarded as the unusual worth of the 36th pregnant week.This value increased by 0.1 with the pregnant weeks decreasing every one week and thus the opposite.ResultsThe unusual checked-out rate 6.8% was stable.ConclusionIt was more helpful for clinical work with S/D unusual worth than S/D≥3.0 simple or with their average or standard deviation as unusual value. ......