胎儿颈项透明层厚度与不良妊娠结局

Relationship between nuchal translucency and adverse pregnant outcomes

目的探讨胎儿颈项透明层（nuchal translucency，NT）厚度增加与妊娠结局的关系，以期用NT预测胎儿临床预后。方法研究对象为2009年2月13日至2010年5月16日在昆明医科大学第一附属医院门诊就诊并行超声检查的妊娠早期单胎孕妇1839例。参照英国胎儿医学基金会的指南测量胎儿头臀径及胎儿NT厚度，随访妊娠结局。将预测不良妊娠结局发生高风险的界值分为NT≥2．0、2．5、3．0、3．5、4．5mm，应用不同的界值，通过绘制受试者工作特征曲线评估NT增厚对不良妊娠结局的预测作用，观察NT增厚对临床结局的影响。用卡方检验或Fisher精确概率法分析敏感性和假阳性率之间的差异。结果1839例孕妇发生不良妊娠结局49例，不良妊娠结局发生率为2．7％。NT界值分别为2．0、2．5、3．0、3．5及4．5mm时，预测总不良妊娠结局的阳性似然比分别为1．6、3．4、12．4、51．0及92．0，不同NT范围不良妊娠结局的发生率依次为2．7％、1．0％、4．0％、17．0％及75．0％。正常妊娠结局的比例随着NT增厚而降低。NT预测总不良妊娠结局的受试者工作特征曲线下面积为0．647，95％CI为0．561-0．732。结论妊娠早期胎儿NT增厚与多种不良妊娠结局相关。不同界值下NT预测不良妊娠结局的发生率可为临床咨询提供客观依据，且NT预测不良妊娠结局的效力达中等水平。

Objective To discuss the relationship between pregnant outcomes and increased fetal nuchal translucency （NT）, and to predict adverse outcomes of fetus with NT. Methods One thousand eight hundred and thirty-nine women who had their antenatal visits in the First Affiliated Hospital of Kunming Medical University from February 13, 2009 to May 16, 2010 were admitted into the study. Crown rump length （CRL） and NT of fetus were measured following the guideline of Fetal Medicine Foundation. Pregnant outcomes were followed-up. The cut-off points of high risk of adverse pregnant outcome were set as NT≥2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm or 4.5 mm. Receiver operating characteristics （ROC） curve was drawn at different cut off points to estimate the value of NT to predict adverse pregnancy outcomes. Differences between sensitivity and false positive rate were analyzed by Chi-square test or Fisher＇ s exact test. Results The adverse outcome rate in this population was 2.7% （49/1839）. The positive likelihood ratios of NT≥2.0 ram, 2.5 mm, 3.0 ram, 3.5 mm and 4.5 mm for adverse outcomes were 1.6, 3.4, 12.4, 51.0 and 92.0, respectively; and the incidences of adverse outcomes were 2.7% , 1.0% , 4.0% , 17.0% and 75.0% , which rose with the increase of NT. Area under ROC curve for adverse outcomes was 0. 647 with 95%CI of 0. 561- 0. 732. Conclusions NT increase is related to adverse pregnant outcomes. The predictive value of different NT for the incidence of adverse outcomes might provide evidence for clinical consultation. NT is applicable in predicting adverse outcomes.