Exploration on the Clinical Significance of the Ultrasonographic Measurement of Nuchal Translucency in Early Pregnancy
|School||Hebei Medical University|
|Course||Medical Imaging and Nuclear Medicine|
|Keywords||ultrasound nuchal translucency crown-rump length prenatalDiagnosis trisomy21syndrome|
Objective：By using ultrasonographic measurement in fetal nuchaltranslucency （referred to as NT） at the1113+6weeks of gestation toinvestigate clinical significance of NT. The relationship of normal fetalgestational age and NT thickness, maternal age and NT thickness wereanalyzed, furthermore the NT thickness cutting value were analyzed by ROC.and pregnancy outcomes in abnormal fetal were discussed.Methods：1283pregnant women from October2011to August2012in the FourthHospital of Hebei Medical University Maternity Ultrasound Division werechose randomly. pregnant women age were18to41,average27.17±3.67yearsold.2Fetal crown to rump length （referred to CRL） were measured byabdominal ultrasound, gestational age were calculated by combining with thelast menstrual projections. NT measurement was recommended by the FetalMedicine Foundation in accordance with British standards.3Through accessing obstetric medical record and telephone follow-upthe pregnancy outcomes. Statistical analysis was performed with SPSS13.0software.Results：1Total of283pregnant women,274cases were normal fetuses,including one case of NT value was3.7mm whose confirmed normalkaryotype by amniocentesis, and it was no obvious abnormalities byfollowed-up to the post-natal. Nine cases of abnormal fetuses including onecase of Trisomy21syndrome, one case of lymphatic hygroma, five cases ofstructural abnormalities, one case of single umbilical artery associated withintrauterine growth retardation and one case the spectrum of the umbilical artery S/D ratio continued to increase.2The NT values of274normal fetuses were divided into three groups byfetal pregnant week,11to11+6weeks,12to12+6weeks and13to13+6weeks of pregnancy. The three groups NT values were compared respectively,p<0.01was considered statistically significant. The NT values were alsodivided into four groups by Maternal age,<25years old,25to29years old,30to34years old,≥35years old. The four groups NT values were comparedrespectively, p=0.995was considered no statistically significant.3NT threshold was showed as2.4mm after the NT values were analyzedby ROC. The sensitivity and the specificity were97.1%and77.8%respectively.Conclusions：1the NT values in normal fetuses of1113+6 weeks were increasedfollowed with the gestational week. The maternal age was not correlated withNT value.2The NT value≥2.4mm was considered as ideal threshold, the risk offetal chromosomal abnormalities and structural abnormalities were increased,the abnormal fetuses can be detected effectively.3Thickened NT was considered as an important indicator in earlypregnancy screen increased，the NT screen showed a significant tool to checkout fetal malformation.4In the cases of Thickened NT, the fetuses should be carried out furtherprenatal diagnosis, in order to check out chromosome abnormalities orstructural abnormalities in pregnancy line system.