Prenatal diagnosis of 2193 pregnant women with invasive indications for chromosomal abnormalities in southern China: a retrospective study

Abstract

Background: Although a variety of non-invasive techniques are used for prenatal genetic screening and diagnosis, our knowledge remains limited regarding the relationship between high-risk prenatal indications and fetal chromosomal abnormalities.Methods: We retrospectively investigated the prenatal genetic screening and karyotype analysis results of pregnant women who had undergone invasive prenatal testing in Prenatal Diagnosis Department of Meizhou People’s Hospital during Jan. 1, 2015 to Dec. 31, 2019. We analyzed the frequencies of chromosome abnormalities in women with high-risk indications.Results: A total of 2,193 pregnant women who had underwent invasive prenatal testing were included in our analysis. Chromosomal abnormalities occurred in 10.3% of these women, and rate increased with maternal age (P < 0.001). The frequencies of chromosome abnormalities varied for women with different high-risk indications, which was 10.3% (226/2193) for abnormal ultrasound results, 3.3% (31/938) for positive serum screening test results, 61.4% (78/127) for positive NIPT results, 9.3% (13/140) for AMA and 11.1% (10/90) for obstetric/family history. Follow up data showed that 380 pregnant women opted for termination the pregnancy, including 211 (55.5%) due to karyotype abnormalities and 169 (45.5%) due to abnormal ultrasonic outcomes.Conclusion: Our data suggested that the prenatal screening methods have high false positive rates. NIPT is the most accurate non-invasive prenatal screening. Apart from karyotype abnormality, abnormal ultrasound results alone accounted for a big part of pregnancy termination.