Detection of copy number variations for chromosome non-numerical abnormality with non-invasive prenatal testing: clinical analysis of 205 cases / 中华围产医学杂志

ABSTRACT

Objective:To evaluate the clinical value of non-invasive prenatal testing (NIPT) in detecting copy number variations (CNVs).Methods:There were 37 845 pregnant women undergoing NIPT in Guangdong Women and Children Hospital from January 1, 2015 to September 1, 2018, of which 205 with CNVs were detected in addition to chromosome numerical abnormality and retrospectively analyzed. Among the 205 cases, 137 received invasive prenatal diagnosis. Pregnant outcomes were followed up and the efficiency of NIPT in detecting CNVs was analyzed by descriptive statistical analysis.Results:The detection rate of NIPT for CNVs was 0.54% (205/37 845). Among the 137 cases undergoing invasive prenatal diagnosis, 110 showed normal karyotype, 27 with abnormal including two having CNVs that were inconsistent with NIPT findings and 25 with consistent results. The positive predictive value, sensitivity and specificity of NIPT for CNVs were 18.2%(25/137), 100.0%(25/25) and 99.7%(37 625/37 737), respectively. Among the 27 pregnant women with positive findings in prenatal diagnosis, five were lost to follow-up; eight terminated their pregnancies; 14 gave birth to alive baby with normal phenotype. While among the 110 pregnant women with negative results in prenatal diagnosis, 87 delivered full-term neonates including two having patent foramen ovale and 85 with normal phenotype; three gave birth prematurely; one terminated pregnancy at 28 +2 gestational weeks due to preeclampsia; two had inevitable abortion; two requested termination and 15 were lost to follow-up. Conclusions:Routine NIPT has high performance in screening CNVs but those pregnant women with positive NIPT results should be counseled after referring to their invasive prenatal diagnosis results, ultrasound scan and clinical information.