ObjectiveTo investigate the coincidence rate of chromosomal abnormalities in pregnant women with different prenatal diagnosis indications, and evaluate the clinical application value of noninvasive prenatal testing(NIPT) of maternal peripheral blood fetal free DNA as a first-line prenatal screening technology.

MethodsThe chromosome karyotype of amniotic fluid cells from ultrasound-guided amniocentesis in 1134 pregnant women with different prenatal diagnosis indications from January 2017 to March 2019 were analyzed.

ResultsA total of 91 cases with abnormal karyotypes were detected, and the abnormal detection rate was 8.02%(91/1134).The abnormal chromosome number(including chimera) in 79 cases(86.81%) was found, which included 21 trisomy in 46 cases, 18 trisomy in 13 cases, 13 trisomy in 4 cases, sexual chromosome abnormality in 6 cases and chimera in 10 cases.The abnormal chromosome structure in 12 cases was identified, and the abnormal detection rate of which was 13.19%(12/91).The coincidence rate of the abnormal amniotic fluid karyotype with different prenatal diagnosis indications included that the positive NIPT of which was 88.24%(the highest)(P < 0.01), the abnormal ultrasound screening of which was 9.73%(the second)(P < 0.01).The differences of the coincidence rates of abnormal amniotic fluid karyotype among the serological screening with high risk(3.81%), high age(3.42), abnormal ultrasound screening(9.73%) and other(2.38%) were not statistically significant(P>0.05).

ConclusionsThe high risk of prenatal serological screening(Down's screening) is the main indication of amniocentesis, which is the highest coincidence rate.The NIPT test in the second trimester can provide more accurate screening and eugenics guidance for pregnant women.