Uncultured chorionic villus samples for fetal chromosome karyotype analysis: a retrospective analysis of 438 cases / 中华围产医学杂志

ABSTRACT

Objective:To understand the possible detected mosaicism chromosome karyotyping using uncultured chorionic villus samples.Methods:This study retrospectively analyzed the clinical data of singleton pregnant women who underwent fetal chromosome karyotyping of uncultured chorionic villus samples at the Prenatal Diagnosis Center of Tianjin Central Hospital of Gynecology and Obstetrics from January 2016 to January 2019. Prenatal diagnosis indicators, fetal karyotypes, the incidence of chromosomal mosaicism and subsequent diagnosis, and perinatal outcomes were analyzed. Amniocentesis was performed when chromosomal mosaicism was identified. Descriptive statistical analysis was used for data analysis.Results:(1) A total of 438 pregnant women with available follow-up data were enrolled. Increased nuchal translucency (56.6%, 248/438) was the major indication for prenatal diagnosis. The karyotype analysis indicated that 79.5% (348/438) were normal, and 2.7% (12/428) were mosaicism. (2) Of the 438 cases, 336 cases (76.7%) were delivered at term, of which 327 cases were uncomplicated. There was one case of premature rupture of membranes within one week after amniocentesis and eight cases of abortion/fetal death between one week after the amniocentesis and 28 weeks of gestation. Of these nine cases, four had chromosomal abnormalities, and five had normal karyotypes. Termination of pregnancy was selected in 65 cases (14.8%) and 28 cases (6.4%) delivered before term. (3) Among the 12 (2.7%) cases of chromosomal mosaicism verified by fetal karyotyping through amniocentesis, four were confined placental mosaicism; six were abnormal chromosomal karyotypes in chorionic villous and amniotic fluid; one was true fetal mosaicism; one was a false positive. Among the 12 cases, three continued to term, one was preterm delivered, and eight selected labor induction, including three cases each of trisomy-21 and ultrasonographic structure abnormalities, and one case each of fetal growth restriction and labor induction based on patient preference.Conclusions:Karyotype analysis of uncultured chorionic villus samples may detect a certain proportion of mosaicism. Therefore, combining fluorescence in situ hybridization to achieve an accurate diagnosis and a detailed and systematic ultrasonic scan are recommended.