ABSTRACT
Objective:To investigate the clinical value of isolated fetal echogenic bowel (FEB) as an indicator for invasive prenatal diagnosis.Methods:This retrospective study enrolled 183 pregnant women who were diagnosed with isolated FEB and underwent invasive prenatal diagnosis in Fujian Maternity and Child Health Hospital from August 2013 to January 2021. Clinical data including the results of conventional karyotyping and chromosomal microarray analysis (CMA), cytomegalovirus (CMV) DNA loads in amniotic fluid and pregnancy outcomes were reviewed analyzed. Chi-square test was used for statistical analysis Results:Karyotyping was performed on all of the 183 fetuses and three (1.64%) aneuploidies (one case of trisomy 21, one trisomy 18 and one 47,XYY syndrome) were detected. One trisomy 21 and four pathogenic (P)/likely pathogenic (LP) copy number variation (CNV) were detected among 108 fetuses who received CMA. The detection rate of P/LP chromosomal abnormalities by CMA was higher than that by karyotyping, but there was no significant difference between them [4.63% (5/108) vs 0.93% (1/108), χ 2=1.54, P>0.05]. In addition, three cases of variants of uncertain significance (VOUS) were detected by CMA. CMV DNA loads of fetal cells in the amniotic fluid samples of the 166 cases were determined, and only one (0.6%) was positive (CMV DNA up to 7.01×10 6 copies/ml), and no abnormalities were found in karyotype analysis and CMA detection. A total of 176 cases were followed up, and among them only one case of intrauterine infection and seven cases (three aneuploidies and four P/LP CNV) of chromosomal abnormalities were terminated after genetic counseling. Three fetuses with VOUS and other 165 fetuses without chromosomal abnormalities had a good prognosis after birth. Conclusions:Isolated FEB may be the abnormal ultrasound finding in fetuses with chromosomal abnormalities or CMV infection. Prenatal genetic testing and the exclusion of intrauterine infection are important for management during pregnancy and prognosis assessment of FEB.
ABSTRACT
OBJECTIVE@#To assess the impact of confined placental mosaicism (CPM) on non-invasive prenatal testing (NIPT) and pregnancy outcomes.@*METHODS@#Copy number variation sequencing (CNV-seq) and single nucleotide polymorphism array (SNP-array) were carried out on placental specimen sampled from eight pregnancies with confirmed false-positive NIPT results. The impact of CPM on NIPT and pregnancy outcomes were analyzed based on the laboratory tests and clinical characteristics.@*RESULTS@#Five of the eight cases with false-positive NIPT results were proven to be CPM involving trisomy 9, 13, 21, 22, and X, respectively. The mosaic ratios for different placental regions have varied from 4% to 80%. Two fetuses with confirmed CPM showed fetal growth restriction (FGR) and additional ultrasound abnormalities, 1 fetus showed only FGR. The remaining two fetuses showed normal growth.@*CONCLUSION@#NIPT is highly sensitive to CPM, whilst CPM is an important cause for false-positive NIPT result. CPM may be associated with FGR. Investigation of the presence of CPM is important for both pre- and post-test genetic counseling and management of the pregnancy.
Subject(s)
Female , Humans , Pregnancy , DNA Copy Number Variations , Mosaicism , Pregnancy Outcome , Prenatal Diagnosis , TrisomyABSTRACT
OBJECTIVE@#To determine the origin of supernumerary small marker chromosomes (sSMCs) carried by two fetuses.@*METHODS@#Single nucleotide polymorphism array (SNP-array) and fluorescence in situ hybridization (FISH) analysis were carried out on cells cultured from the amniotic fluid samples.@*RESULTS@#SNP-array analysis showed both fetuses to be arr[hg19]22q11.1q11.21(16 888 899-18 649 190)×4, with a duplicated 1.7 Mb region (16 888 899-18 649 190) leading to partial tetrasomy of 22q11.1-22q11.21. FISH confirmed that both fetuses were 47,XN,+mar.ish idic(22)(q11.2) (RP11-958H20 ++),which suggested a diagnosis of Cat-eye syndrome (CES). The appearance of abortuses were consistent with the diagnosis of CES.@*CONCLUSION@#Two fetuses with CES were diagnosed by genetic testing. The latter has provided a basis for genetic counseling.