The Relationship between Prenatal Diagnosis Indications and Abnormal Chromosomal Karyotypes: A Retrospective Cohort of 4646 Cases in Beijing from 2012-2019

Background and Objective: Chromosomal abnormalities are one of the genetic disorders caused by abnormal chromosome number or structure and can endanger multiple organs, morphology and function of the systems in the human body. This study aims to investigate the relationship between prenatal diagnosis indications and abnormal karyotypes to improve prenatal screening. Methods: The karyotype analyses were carried out on 4646 pregnant women with prenatal diagnosis indications referred to the first medical center of Chinese PLA General Hospital from 2012 to 2019. The incidence, distribution, and statistical features of chromosomal abnormality of different prenatal diagnosis indications were analyzed, and the relationships with the prenatal diagnosis indications were assessed. Results: A total of 351 fetal chromosomal abnormalities were detected in 4646 karyotypes, with an incidence of 7.6%. The chromosomal abnormality incidence in the single indication group, two indications group, and three indications group was 5.8%, 16.1%, and 70.0%, respectively, indicating a statistically significant difference (p < 0.05). Advanced maternal age (AMA), high-risk maternal serum screening (MSS), and non-invasive prenatal DNA testing (NIPT) were the important indications for predicting abnormal karyotype. The number of prenatal diagnosis indications was highly correlated with fetal chromosomal abnormalities. The overall incidence of chromosomal abnormalities showed a tendency to increase with age. The incidence of Trisomy 21 was 3.2%, accounting for 42.5% of all chromosomal abnormalities, and the incidence tended to increase with maternal age. Conclusion: Prenatal karyotype analysis of pregnant women with prenatal diagnosis indications can effectively prevent the birth of defective children. AMA, MSS and NIPT were the important indications for predicting abnormal karyotype. In addition, the number of prenatal diagnosis indications is highly correlated with chromosomal abnormalities.