Retrospective Analysis Of The Relationship Between Abnormal Fetal Ultrasonic Markers And Chromosomal Abnormalities

Objective:To retrospectively analyze the fetal ultrasound signs of 15831 pregnant women(singleton)screened by systematic antenatal ultrasound,and to analyze the ultrasonic indexes(including soft markers and structural malformations)and the occurrence of chromosome abnormalities.To explore the correlation between various ultrasonic abnormalities detected by screening and non-invasive preparturient gene detection(NIPT)and chromosome abnormalities confirmed by amniotic fluid puncture and their relationship with pregnancy outcome.The basical purpose of this paper is to provide objective and scientific evidence-based and clinical guidance for antenatal counseling for pregnant women.Methods The fetal ultrasound signs of 15831 pregnant women(singleton)screened by systematic antenatal ultrasound(about 20-25 weeks),from January 1st,2017 to December 31st,2018 in our hospital were analyzed retrospectively.The abnormal ultrasound markers(including soft index and structural malformation)and the occurrence of chromosome abnormalities were statistically analyzed.A comprehensive examination of the fetus was performed by abdominal ultrasound.The sensitivity,specificity,negative and positive predictive value of single and multiple abnormal ultrasound markers in the diagnosis of fetal chromosome abnormalities were recorded and analyzed respectively,and the sensitivity,specificity,negative and positive predictive value of each structural malformation in the diagnosis of fetal chromosome abnormalities were analyzed.The relevance between different ultrasound soft markers and fetal structural abnormalities was analyzed at the same time.Telephone-followed pregnancy outcomes were performed in 376 patients with fetal structural malformation and 903 patients with soft markers systematically screened.Results 1.Among the 15831 pregnant women(singletons)who underwent systematic antenatal ultrasound screening during the data acquisition period,a total of 1279 cases of abnormal ultrasound markers were detected.Among them,903 fetuses with abnormal soft index were found(including partial structural deformities),with an abnormal incidence of 5.70%.There were 894 fetuses with abnormal single soft index,accounting for 99.00%of the total soft index abnormality,and 24 among them were with chromosome abnormalities.The sensitivity and specificity of diagnosing chromosome abnormality were 46.15%and 94.49%,respectively.There were 9 cases with soft index and 4 cases with chromosome abnormality.The sensitivity and specificity of diagnosing chromosome abnormality were 7.69%and 99.97%,respectively.A total of 376 fetuses with fetal structural malformations were detected(soft index combined with nonrepeated count of structural deformity),and the rate of fetal structural malformations was 2.37%.It covered almost all systems in fetuses in the second trimester of pregnancy,including cardiovascular system,maxillofacial region,nervous system,skeletal system,urinary system,digestive system and so on.Among them,127 cases were single structural malformations and 5 cases were complicated with chromosome abnormalities.The sensitivity and specificity of diagnosing chromosome abnormalities were 9.62%and 99.23%.There were 249 cases of multiple structural malformations and 19 cases of chromosome abnormalities.The sensitivity and specificity of diagnosing chromosome abnormalities were 36.54%and 98.54%.2.NIPT detection was performed in 4845 cases in our hospital.The results showed that the risk of aneuploid chromosome abnormality was low in 4761 cases(98.27%)and high in 84 cases(1.73%).Amniotic fluid puncture examination was performed in 74 of 84 non-invasive high-risk pregnant women.22 cases(29.73%)were diagnosed as normal chromosomes by karyotype analysis,and 52 cases(70.27%)were diagnosed as chromosome abnormalities.3.The follow-up results showed that among the 22 fetuses with normal chromosomes diagnosed by amniotic fluid puncture,1 case of renal sinus separation aggravated labor induction in the third trimester of pregnancy,and 2 cases of lateral ventricle dilatation aggravated labor induction.The other 5 women chose to continue pregnancy.Among the 8 fetuses with single non-fatal structural malformation,2 women chose to continue pregnancy and the follow-up results were consistent with the ultrasonic diagnosis.And the other 6 women chose to terminate pregnancy,3 women with normal ultrasound markers continued to pregnancy until delivery,and the follow-up results indicated that all babies developed normally.4 pregnant women with multiple fetal structural malformations chose to terminate pregnancy.52 pregnant women with chromosome abnormalities diagnosed by amniotic fluid puncture were accompanied by abnormal ultrasonic markers.1 with facial fissure and 1 with small jaw accompanied with ventricular septum defect chose to continue pregnancy,and all the rest chose to terminate pregnancy.Conclusion1.In this study,the structural malformations detected by systematic ultrasound screening covered almost all fetal systems,and the screening of severe structural malformations and all kinds of soft markers in the second trimester of pregnancy could indicate the outcome of pregnancy.Ultrasound examination of cardiovascular system should be used as an important site for targeted examination.2.In this study,single and multiple ultrasound soft markers and single and multiple structural abnormalities can be used to diagnose chromosome abnormalities to a certain extent,and the predictive values of multiple soft index abnormalities in chromosome abnormalities are higher.Among them,nasal bone abnormality,choroid plexus cyst and intestinal echo enhancement accounted for a higher proportion in all trisomy fetuses,followed by slight broadening of lateral ventricle,thickening of posterior cervical skinfold and single umbilical artery.However,no fetus with trisomy syndrome was found in mild pyelectasis and short humerus/femur.3.The results of follow-up showed that the abnormal screening results of fetal aneuploidy by NIPT were in good agreement with those of amniotic fluid puncture,which could greatly reduce the puncture rate of invasive antenatal diagnosis.