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Objective To investigate the value and safety of first-trimester chorionic villus sampling (CVS) in prenatal diagnosis.Methods This study retrospectively analyzed the clinical data of 985 cases undergoing CVS and prenatal diagnosis with karyotyping and fluorescence in situ hybridization (FISH) in the Department of Obstetrics and Gynecology of Peking University First Hospital from January 2012 to December 2017.The success rate of cell culture,indications for prenatal diagnosis,karyotyping results,and complications of CVS were described.Results Among the 985 cases,970 (98.48％) underwent FISH and 893 (90.66％) received karyotyping,and 878 (89.14％) accepted both.After CVS,the success rate of cell culture was 96.64％ (863/893).Abnormal ultrasonographic findings (42.64％,420/985) were the most common indications for prenatal diagnosis.In this study,181 cases of chromosomal abnormalities were detected,including numerical and structural abnormalities,accounting for 18.38％ of all 985 cases.Those cases with abnormal ultrasonographic images had the highest detection rate of chromosomal abnormalities (31.90％,134/420),followed by those with adverse pregnant history (11.83％,20/169) and advanced maternal age (8.21％,11/134).In addition,there was a discrepancy between karyotyping and FISH results,which might due to 16 cases of placental mosaicism and 13 cases of maternal cell contamination (MCC).Embryonic demises were reported in six cases (0.61％,6/985),including four with chromosomal numerical abnormalities within four weeks after CVS.No other short-or long-term postoperative complications were found in the rest 979 cases (99.39％).Conclusions CVS in the first trimester is a safe and reliable invasive method for prenatal diagnosis,which can help to obtain an earlier diagnosis in a certain population such as those with abnormal ultrasonographic findings,thus improve the pertinence and efficiency of prenatal diagnosis.However,the potential influences of placental mosaicism and MCC on the diagnostic results should not be ignored.
ABSTRACT
Objective@#To investigate the value and safety of first-trimester chorionic villus sampling (CVS) in prenatal diagnosis.@*Methods@#This study retrospectively analyzed the clinical data of 985 cases undergoing CVS and prenatal diagnosis with karyotyping and fluorescence in situ hybridization (FISH) in the Department of Obstetrics and Gynecology of Peking University First Hospital from January 2012 to December 2017. The success rate of cell culture, indications for prenatal diagnosis, karyotyping results, and complications of CVS were described.@*Results@#Among the 985 cases, 970 (98.48%) underwent FISH and 893 (90.66%) received karyotyping, and 878 (89.14%) accepted both. After CVS, the success rate of cell culture was 96.64% (863/893). Abnormal ultrasonographic findings (42.64%, 420/985) were the most common indications for prenatal diagnosis. In this study, 181 cases of chromosomal abnormalities were detected, including numerical and structural abnormalities, accounting for 18.38% of all 985 cases. Those cases with abnormal ultrasonographic images had the highest detection rate of chromosomal abnormalities (31.90%, 134/420), followed by those with adverse pregnant history (11.83%, 20/169) and advanced maternal age (8.21%, 11/134). In addition, there was a discrepancy between karyotyping and FISH results, which might due to 16 cases of placental mosaicism and 13 cases of maternal cell contamination (MCC). Embryonic demises were reported in six cases (0.61%, 6/985), including four with chromosomal numerical abnormalities within four weeks after CVS. No other short- or long-term postoperative complications were found in the rest 979 cases (99.39%).@*Conclusions@#CVS in the first trimester is a safe and reliable invasive method for prenatal diagnosis, which can help to obtain an earlier diagnosis in a certain population such as those with abnormal ultrasonographic findings, thus improve the pertinence and efficiency of prenatal diagnosis. However, the potential influences of placental mosaicism and MCC on the diagnostic results should not be ignored.
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Objective To investigate the detection rate,clinical indications and pregnancy outcomes of pregnancies with prenatally diagnosed small supernumerary marker chromosome (sSMC) to provide a theoretical foundation for prenatal diagnosis and genetic counseling of sSMC.Methods This study retrospectively analyzed the clinical data of 20541 cases who underwent prenatal diagnosis at the Prenatal Diagnostic Center in the Department of Obstetrics and Gynecology in Peking University First Hospital from January 2007 to May 2018.The detection rate,diagnostic indications and pregnancy outcomes of the cases with sSMC were analyzed after cell culture and karyotyping.Array comparative genomic hybridization (aCGH) was used to analyze the origin of fetal abnormal chromosome in some cases.Results Prenatal diagnostic samples of 20486 cases were successfully cultured,among which 20 (sSMC) were detected giving an detection rate of 0.98‰,while the figures in samples obtained through chorionic villus sampling,amniocentesis and umbilical cord blood sampling were 2.20 ‰ (2/910),0.74 ‰ (14/18824) and 5.32 ‰ (4/752),respectively.Twelve cases of mosaic karyotype were also found.In gravidas for prenatal diagnosis indicated by maternal or paternal chromosomal abnormality,fetal structural anomalies on ultrasonography,adverse pregnant history,advanced maternal age and high risk of Down's syndrome,the detection rates of sSMC were 10.42 ‰ (1/96),2.65 ‰ (4/1507),1.89 ‰ (5/2 643),0.83‰ (8/9 624) and 0.49‰ (2/4013),respectively.Eleven cases were further analyzed with aCGH,four of which showed pathogenic copy number variants involving 2q11.1-q12.1,2p12-p11.1 and 2q11.1-q12.1,7q 11.21-q 11.23 and 15q11.1-q 13.3 dup1ications and terminated the pregnancies.Seven cases carried nonpathogenic marker chromosomes,of which one terminated the pregnancy,while the other six continued to fullterm with uneventful outcomes until follow-ups.Conclusions sSMC is hard to detect in prenatal diagnosis,but maternal or paternal chromosomal abnormalities,fetal structural anomalies on ultrasonography and adverse pregnancy and childbirth history are strong indications.Cytogenetics and molecular diagnosis combined can clarify the character,origin and pathogenicity of sSMC,and is of great clinical importance in prenatal genetic counseling and maternal decision making.