Comparison of Chromosomal Microarray Analysis and Noninvasive Prenatal Testing in Pregnant Women with Fetal Ultrasonic Soft Markers

Chromosomal Microarray Analysis and Karyotype Analysis for Prenatal Diagnosis of Fetuses With Abnormal Ultrasound Soft Markers

OBJECTIVE

To explore and evaluate the value of chromosomal microarray analysis (CMA) in fetuses with abnormal ultrasound soft markers.

METHODS

A retrospective study was conducted on 193 fetuses with abnormal ultrasound soft markers who received prenatal diagnosis at Meizhou People's Hospital, between October 2022 and February 2024. Genetic detection of fetal specimens obtained by ultrasound-guided puncture was carried out. The detection rates of karyotype analysis and CMA for chromosomal abnormalities in different ultrasonic abnormalities were analyzed.

RESULTS

Of the 193 fetuses, there were 77 (39.9%) fetuses with increased nuchal translucency(NT) thickness, 33 (17.1%) with ventriculomegaly, 29 (15.0%) with nasal bone hypoplasia, followed by choroid plexus cyst, pyelic separation, echogenic bowel, single umbilical artery, with persistent left superior vena cava, and persistent right umbilical vein. Aneuploidy was mainly found in fetuses with increased NT thickness or and nasal bone hypoplasia, while P/LP CNVs were mainly concentrated in fetuses with increased NT thickness or ventriculomegaly. The detection rate of karyotype was 5.7% (11/193), the detection rate of aneuploidy plus P/LP CNVs in fetuses with abnormal ultrasonic soft markers by CMA was 10.9% (21/193), and the additional detection rate of CMA was 5.2%.

CONCLUSIONS

CMA can significantly improve the detection rate of chromosomal abnormalities in fetuses with abnormal ultrasonic soft markers compared with karyotype analysis. There was a significant difference in detection rates of chromosomal abnormality between CMA and karyotype analysis in the single ultrasonic abnormality group, but none in the multiple ultrasonic abnormalities group.

Clinical value of screening prenatal ultrasound combined with chromosomal microarrays in prenatal diagnosis of chromosomal abnormalities

OBJECTIVE

To evaluate the clinical value of ultrasound findings in the screening of fetal chromosomal abnormalities and the analysis of risk factors for chromosome microarray analysis (CMA) abnormalities.

METHODS

We retrospectively analyzed the datasets of 15,899 pregnant women who underwent prenatal evaluations at Affiliated Maternity and Child Health Care Hospital of Nantong University between August 2018 and December 2022. Everyone underwent ultrasound screening, and those with abnormal findings underwent CMA to identify chromosomal abnormalities.

RESULTS

The detection rates for isolated ultrasound anomalies and combined ultrasound and CMA anomalies were 11.81% (1877/15,899) and 2.40% (381/15,899), respectively. Among all ultrasound abnormalities, detection rates for isolated ultrasound soft marker anomalies, isolated structural abnormalities, and both ultrasound soft marker anomalies with structural abnormalities were 82.91% (1872/2258), 15.99% (361/2258), and 1.11% (25/2258), respectively. The detection rate of abnormal chromosomes in pregnant women with abnormal ultrasound results was 16.87% (381/2258). The detection rates were 13.33% in cases with two or more ultrasound soft markers anomalies, 47.37% for two or more structural anomalies, and 48.00% for concomitant ultrasound soft marker and structural anomalies.

CONCLUSIONS

Enhanced detection rates of chromosomal anomalies in fetal malformations are achieved with specific ultrasound findings (NT thickening, cardiovascular abnormalities, and multiple soft markers) or when combined with high-risk factors (advanced maternal age, familial history, parental chromosomal anomalies, etc.). When the maternal age is over 35 and with ≥2 ultrasound soft marker anomalies accompanied with any high-risk factors, CMA testing can aid in the diagnosis of prenatal chromosomal abnormalities.