胎儿颈项透明层增厚的临床咨询及预后分析

Clinical consultation and prognosis analysis of fetus with increased nuchal translucency

目的·研究颈项透明层(nuchal translucency,NT)增厚与胎儿染色体异常、严重结构畸形和其他严重异常的关系,了解其在评估胎儿预后中的价值。方法·对583例妊娠早期(11~13^(+6)周)NT≥2.5 mm的单胎病例进行回顾性分析,其中252例行介入性产前诊断,统计胎儿染色体核型,随访胎儿超声筛查结构异常情况及妊娠结局。按NT厚度将其依次分为5组:组1~4的NT厚度分别为2.5~2.9 mm、3.0~3.4 mm、3.5~4.4 mm和≥4.5 mm;组5为颈部水囊瘤胎儿组。利用趋势χ~2检验和Fisher确切概率法比较几种常见染色体异常胎儿的NT值。结果·583例NT增厚胎儿中,染色体核型异常59例(23.4%,59/252);结构异常38例(6.5%),其中严重心脏畸形13例(2.2%)。产前诊断术后无自然流产及宫内感染,引产86例,死胎6例,难免流产3例,自行终止妊娠8例,出生后死亡2例,活产478例。5组胎儿染色体异常、结构异常及心脏畸形的发生率差异均有统计学意义(P=0.000),发生率具有随着NT增厚而升高的趋势;组1~5存活率分别为96.5%、81.9%、74.0%、35.6%和6.7%,随NT增厚而下降(P=0.000)。结论·NT增厚与胎儿染色体异常、严重心脏畸形等不良妊娠结局有关;随着NT增厚,胎儿染色体异常、结构异常及心脏畸形的发生率升高,不良妊娠结局的风险增加;临床工作中需根据NT不同厚度给予个性化咨询及指导。

Objective To investigate the correlation between increased nuchal translucency（NT） thickness and fetal chromosomal abnormalities, severe structure anomalies and other abnormalities, and its value in assessment of fetal prognosis. Methods Five hundred and eighty-three singleton fetuses with NT ≥ 2.5 mm in the first trimester（11-13-（＋6） week） were retrospectively analyzed, of which 252 had invasive prenatal test for fetal chromosome and genetic tests. They were divided into 5 groups according to the NT thickness, 2.5 - 2.9 mm, 3.0 - 3.4 mm, 3.5 - 4.4 mm, and ≥ 4.5 mm as 1st to 4th group, and cystic hygroma as 5th group.The incidences among groups were analyzed by Cochran-Armitage Trend test. Fisher＇s exact test was used to compare diversities of NT thickness among the major chromosomal abnormalities. Results Among the 583 singleton fetuses, 59 were diagnosed as chromosomal abnormalities（23.4%, 59/252）, 38 with structure anomalies（6.5%）, of which 13 cases with severe cardiac anomalies（2.2%）.There were 6 fetal demise, 3 inevitable abortion, 2 stillborn, 94 terminations of pregnancy（8 for personal factors） and 478 live birth, without spontaneous abortions and congenital infections after invasive prenatal test. The differences among the incidences of chromosomal abnormalities, structure anomalies and cardiac anomalies in five groups were statistically significant（P=0.000） and the incidences all increased with fetal NT thickness. The healthy living rates of fetus were 96.5%, 81.9%, 74.0%, 35.6%, and 6.7% among groups, respectively, and the incidences all decreased with fetal NT thickness（P=0.000）. Conclusion Increased NT thickness is related to fetal chromosomal abnormalities, severe cardiac anomalies and poor pregnant outcome. The incidences of chromosomal abnormalities, structure anomalies, cardiac anomalies and pregnant outcome all increase with fetal NT thickness. In clinical practice, individualized guidance should be conducted according to different thickness of NT.