关键词: 颈项透明层, 妊娠结局, 孕妇, 高龄

Abstract: 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.

Key words: Nuchal translucency, Pregnancy outcome, Pregnant women, Advanced maternal age