Ultrasound Screening In The Application Of Fetal Chromosomal Diseases In Second And Third Trimester

Objective:This study was to investigate the application and significance of ultrasound in detecting the fetal chromosomal diseases in pregnant women with isolated abnormal serum marker on second serum trimester triple screen,and provide an important basis for fertility.Methods:From June 2007 to April 2009,among 8469 pregnant women underwent second trimester serum triple screen at the Xiangtan Central Hospital and the Third Xiangya Hospital attached to Central South University,1217 patients whose Down syndrome risk was lower than 1:270 and trisomy 18 risk lower than 1:350 had isolated abnormal serum marker(AFP MoM≥2.5,AFP MOM＜0.7,HCG MoM＞2.5,HCG MoM＜0.25,uE3 MoM＜0.7).Subsequently,all 1217 patients had complete color Doppler ultrasound examination at 18-32 weeks.99 of the 1217 patients had abnormal ultrasound findings designed as patient group and underwent for chromosomal karyotyping.Among the remaining patients who had normal ultrasound,95 patients were recruited as a control group and underwent for chromosomal karyotyping.The rate of chromosomal abnormalities were compared in both groups.Maternal obstetric histories were collected for patient group.Comparisons of the rate of anomaly of chromosome in cases which have different abnormal ultrasound or have different histories of pregnancy.Neonatal outcomes were also collected. Autopsy examinations were conducted on terminated pregnancies.Results:1.In the patient group,97 of 99 patients had successfully karyotyping.9 of the 97 cases had abnormal karyotyping,the detection rate is 9.28% (9/97).In the control group,91 of 95 patients had successfully karyotyping,and no chromosomal abnormality was found(0%,0/91). The proportion of anomaly of chromosome of fetus was higher in cases than in controls sufficiently(P＜0.01 ).2.For patient group,the rate of fetal chromosomes in pregnant women having bad outcome in previous pregnancy is 18.42%.The rate of fetal chromosomes in pregnant women without bad outcome in previous pregnancy is 3.39%.The proportion of anomaly of chromosome of fetus was high in cases who had bad.outcome in previous pregnancy(P3.In fetus with multiple ultrasound abnormalities,the rate of chromosomal abnormality is 17.5%.In contrast,the rate of chromosomal abnormality in fetus with single ultrasound abnormality is 3.51%.The difference between the two groups is statistically significant(P＜0.05).Conclusion:1.Patients with Down syndrome risk lower than 1:270 and trisomy 18 risk lower than 1:350 but with isolated abnormal serum marker should undergo complete ultrasound examination.If there is abnormal ultrasound finding,the risk for chromosome abnormality is higher. These patients should be consulted for karyotyping.2.To screen Down's syndrome and other anomaly of chromosome of fetus using ultrasound examination in those pregnant women having abnormal individual serum indicators.The tests prove ultrasound screening for fetal chromosomal is feasible in the second and third trimester.3.Whether the pregnant women have bad outcome in previous pregnancy or not is closely related to the possibility of chromosomal abnormality of her offspings.4.The fetus with multiple ultrasound abnormalities is closely related to the possibility of chromosomal abnormality.5.To study no-invasive screening and diagnosis for fetus of chromosome anomalies plays a great role to detect the cause,diagnosis and termination of pregnancy.That is high clinical value to reduce birth defects and raise the quality of the population.