Karyotype analysis with amniotic fluid in 12365 pregnant women with indications for genetic amniocentesis and strategies of prenatal diagnosis

Abstract

We explored the strategies of prenatal diagnosis by foetal karyotype analysis in pregnant women with indications for genetic amniocentesis. Karyotype analysis of amniotic fluid was performed on 12365 pregnant women with indications for genetic amniocentesis. The detection rates and distributions of abnormal karyotypes were observed in a variety of indications for genetic amniocentesis. The detection rates of abnormal karyotype were 57.4% in either a mother or father with chromosomal abnormality, 8.5% in the pregnant women with pathological ultrasound finding (PUF), 2.79% in the pregnant women with advanced age (35 years and over) and 2.23% in the women with abnormal maternal serum screening (MSS) tests. Foetal abnormal karyotype was found in 86 pregnant women with PUF; of the 86 pregnant women, 42 had trisomy 13, 18 or 21. Of the 12365 pregnant women, foetal abnormal karyotype was found in 428 (3.46%); of the 428 foetuses, only 154 had trisomy 13, 18 or 21. In the pregnant women with abnormal MSS, 111 foetuses had abnormal karyotype, but only 36 foetuses had trisomy 13, 18 or 21. We conclude that (1) ultrasound is an important approach to prevent the birth of foetuses with chromosomal disease. (2) Non-invasive prenatal DNA detection cannot completely replace invasive prenatal diagnosis and MSS. (3) The strategies of prenatal diagnosis: Genetic amniocentesis is strongly recommended for the pregnant women with indications for genetic amniocentesis. For pregnant women who refuse invasive prenatal diagnosis, non-invasive prenatal DNA detection is first performed. If the results of non-invasive prenatal DNA detection are negative, the pregnant women are followed up by ultrasound; if the results of non-invasive prenatal DNA detection are positive, the pregnant women should undergo invasive prenatal diagnosis.

Keywords: Amniocentesis; chromosome abnormality; prenatal diagnosis; trisomy 21.