高龄孕妇胎儿颈项透明层增厚的临床价值研究

目的　探讨高龄孕妇（≥35岁）产前超声诊断胎儿颈项透明层（NT）增厚的临床价值。方法　查阅2015年7月—2016年12月于浙江省立同德医院行胎儿NT测定的1 053例单胎高龄孕妇的病历资料，以NT≥2.5 mm为截断点，选取其中经产前超声诊断胎儿NT增厚的51例高龄孕妇为NT增厚组，随机选取同期经产前超声诊断胎儿NT正常的204例高龄孕妇为NT正常组。比较两组异常妊娠结局、胎儿结构畸形、染色体畸形的发生情况。结果　高龄孕妇胎儿NT增厚的发生率为4.84％（51/1 053）。NT正常组204例孕妇中因胎儿畸形而采取医疗性终止妊娠1例（引产后发现胎儿系水囊样淋巴瘤），胎死宫内1例，失访2例；NT增厚组51例孕妇中发现重大胎儿畸形而采取医疗性终止妊娠21例，胎死宫内5例，出生后发现胎儿水囊样淋巴瘤1例，失访1例。NT增厚的高龄孕妇异常妊娠发生率为54.0%（27/50），NT正常的高龄孕妇异常妊娠的发生率为1.0%（2/202），差异有统计学意义（χ2=105.450，P<0.001）。NT正常组1例终止妊娠的胎儿系孕18+周B超发现水囊状淋巴瘤，随后行羊膜腔穿刺检查提示22号染色体结构异常，故采取医疗性终止妊娠；NT增厚组医疗性终止妊娠的21例胎儿中术前均经过羊膜腔穿刺和产前B超诊断，9例为染色体异常，12例胎儿有严重结构畸形（其中含染色体异常7例），9例水囊状淋巴瘤（其中含染色体异常2例）。NT增厚的高龄孕妇胎儿染色体异常发生率20.0%（9/45），NT正常的高龄孕妇胎儿染色体异常的发生率0.5%（1/202），差异有统计学意义（χ2=101.589，P<0.05）。结论　高龄孕妇胎儿NT增厚组异常妊娠、染色体异常发生率高于NT正常组，胎儿NT测定对于不良妊娠、染色体异常具有一定的预测价值。

Clinical Value of the Detection of Fetal Nuchal Translucency Thickening in Pregnant Women with Advanced Maternal Age

Objective　To evaluate the clinical value of prenatal ultrasound in detecting the thickening of fetal nuchal translucency（NT） in women of advanced maternal age（≥35 years）．Methods　The data from 1 053 pregnant women of advanced maternal age with singleton pregnancies who underwent NT determinations in Tongde Hospital of Zhejiang Province between July 2015 and December 2016 were collected.With a NT ≥ 2.5 mm as the cut-off point，51 pregnant women diagnosed with NT thickening by ultrasound were selected as the NT thickening group.The NT normal group consisted of 204 pregnant women randomly selected from the women who were diagnosed with normal NT by ultrasound during the same period.Abnormal pregnancy outcomes，fetal malformations，and chromosome abnormalities were compared between the two groups.Results　The incidence of fetal NT thickening in this cohort was 4.84%（51/1 053）．In the NT normal group，among 204 pregnant women，there was 1 gravida who underwent medical termination of pregnancy due to a fetal malformation（a cystic hygroma was detected after induction of labor），1 intrauterine fetal death，and 2 gravidas lost to follow-up.Among the group of 51 with NT thickening，there were 20 gravidas who underwent medical termination of pregnancy due to major fetal malformations，5 intrauterine fetal deaths，1 fetal cystic hygroma，and 1 gravida lost to follow-up.The incidence of abnormal pregnancies in the pregnant women with NT thickening and advanced age was 54.0%（27/50），and the incidence in pregnant women with normal NT and advanced age was 1.0%（2/202）；the difference was significant（χ2=105.450，P<0.001）．The medical termination of pregnancy in the NT normal group was shown to have a cystic hygroma by ultrasound at 18+ weeks gestation.A subsequent amniocentesis indicated a structural abnormality of chromosome 22，thus medical termination of pregnancy was performed.In the NT thickened group，21 gravidas who underwent medical terminations of pregnancy had amniocenteses and prenatal ultrasound examinations；9 fetuses had chromosomal abnormalities，12 had severe structural malformations（7 cases also had chromosomal abnormalities），and 9 had cystic hygromas（2 also had chromosomal abnormalities）．The incidence of chromosomal abnormalities in the NT thickening group was 20.0%（9/45），and the incidence of chromosornal abnormalities in the NT normal group was 0.5%（1/202），which was significantly lower than the NT thickening group（χ2=101.589，P<0.05）．Conclusion　The incidence of abnormal pregnancies，and chromosomal abnormalities in the women of advanced maternal age and NT thickening was higher than the incidence in the NT normal women.Fetal NT thickness examinations have a predictive value for abnormal pregnancies and chromosomal abnormalities.