探讨早孕期胎儿颈项透明层(NT)增厚与鼻骨缺失的产前诊断价值。

选择2016年10月至2019年4月，于东莞市人民医院进行早孕期胎儿超声检查发现胎儿NT增厚和(或)鼻骨缺失的488例单胎妊娠胎儿为研究对象。回顾性分析其孕母的临床病例资料。对单纯NT增厚、单纯鼻骨缺失、NT增厚+鼻骨缺失、NT增厚+其他结构畸形、NT增厚+鼻骨缺失+其他结构畸形5种情况胎儿的染色体病发生率，采用χ²检验进行统计学比较。本研究遵循的程序符合2013年修订的《世界医学协会赫尔辛基宣言》要求。

①本组接受产前诊断的NT增厚、鼻骨缺失胎儿的染色体病发生率分别为17.6%(46/262)和14.3%(29/203)。②本组单纯NT增厚、单纯鼻骨缺失、NT增厚+鼻骨缺失、NT增厚+其他结构畸形、NT增厚+鼻骨缺失+其他结构畸形5种情况胎儿的染色体病发生率分别为8.5%(17/200)、3.9%(3/77)、53.5%(23/43)、43.5%(10/23)、42.9%(6/14)。单纯NT增厚与单纯鼻骨缺失胎儿染色体病发生率比较，差异无统计学意义(χ²＝1.759，P＝0.090)；NT增厚+鼻骨缺失、NT增厚+其他结构畸形、NT增厚+鼻骨缺失+其他结构畸形3种情况胎儿染色体病发生率比较，差异无统计学意义(χ²＝0.837，P＝0.658)；但是这3种情况的胎儿染色体病发生率，均显著高于单纯NT增厚胎儿，并且差异均有统计学意义(χ²＝52.080、23.716、16.101，均为P<0.001)。

建议对早孕期孕妇进行胎儿超声检查时，将鼻骨缺失筛查列为胎儿染色体病筛查的有价值指标之一，中孕期对鼻骨缺失胎儿的影像学追踪亦很重要。早孕期胎儿NT增厚合并鼻骨缺失和(或)其他结构畸形时，强烈建议孕妇进行产前诊断，以了解胎儿染色体病发生情况。

To investigate prenatal diagnosis value of increased nuchal translucency (NT) thickness and absence of nasal bone of fetal in first trimester.

From October 2016 to April 2019, a total of 488 cases of singleton pregnancy fetus who were screened by ultrasound to confirm the increased NT thickness and/or absence of nasal bone in first trimester in Dongguan People′s Hospital were selected as research subjects. The clinical date of pregnant women of fetus were analyzed retrospectively.Chi-square test was used to compare the incidence of chromosomal abnormalities under 5 ultrasound conditions, including isolated increased NT thickness, isolated absence of nasal bone, increased NT thickness + absence of nasal bone, increased NT thickness + other structure abnormalities, and increased NT thickness + absence of nasal bone + other structure abnormalities. The procedure followed in this study was consistent with World Medical Association Declaration of Helsinki revised in 2013.

①The incidence of chromosomal abnormalities of fetuses who received prenatal diagnosis and diagnosed with increased NT thickness and absence of nasal bone were 17.6% (46/262) and 14.3% (29/203), respectively. ②The incidence of chromosomal abnormalities of fetus with isolated increased NT thickness, isolated absence of nasal bone, increased NT thickness + absence of nasal bone, increased NT thickness + other structure abnormalities, and increased NT thickness + absence of nasal bone + other structure abnormalities were 8.5% (17/200), 3.9% (3/77), 53.5% (23/43), 43.5% (10/23), 42.9% (6/14), respectively. Among them, there was no significant difference of incidence of chromosomal abnormalities between fetus with isolated increased NT thickness and isolated absence of nasal bone (χ²=1.759, P=0.090). There was no significant difference of incidence of chromosomal abnormalities among fetus with the rest of 3 ultrasound conditions (χ²=0.837, P=0.658). But the incidence of chromosomal abnormalities of fetus with these 3 ultrasound conditions were all higher than that of fetus with isolated increased NT thickness, and the differences were statistically significant(χ²=52.080, 23.716, 16.101; all P<0.001).

Nasal bone screening should be included as a screening index of chromosomal abnormality in first trimester, and fetus with nasal bone abnormality should be followed up in second trimester. It is highly recommended that pregnant women take prenatal diagnosis while ultrasound scan showed fetus with increased NT thickness combined with absence of nasal bone and/or with other structure abnormalities to identify fetus condition of occurrence of chromosomal abnormality.