OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) for the detection of low-level mosaicisms in amniotic fluid samples, and to retrospectively analyze the rare cases of mosaicisms. METHODS: Chromosomal karyotype of the fetus was determined by G-banding analysis of cultured amniotic fluid cells. CMA was used to detect copy number variation of fetal chromosomes, and fluorescence in situ hybridization (FISH) was used to determine the proportion of fetal chromosomal mosaicisms in uncultured amniotic fluid cells. RESULTS: Among 825 prenatal samples, 4 cases of true fetal mosaicisms were detected, which yielded an incidence of 0.48%. Two cases were sex chromosomal mosaicisms, and two were autosomal mosaicisms, which involved chromosomes 8 and 9, respectively. All cases were verified by G-banding analysis of cultured amniotic fluid cells, CMA, and/or FISH. CONCLUSION CMA has a great value for detecting low-level mosaicisms in amniotic fluid samples, though the positive results need to be verified by other techniques and should be interpreted with caution. The review of rare cases can provide a basis for prenatal genetic counseling.
Humans ; Female ; Amniotic Fluid/metabolism* ; Pregnancy ; Mosaicism/embryology* ; Prenatal Diagnosis/methods* ; Adult ; In Situ Hybridization, Fluorescence ; Microarray Analysis/methods* ; Karyotyping ; Retrospective Studies ; Male

OBJECTIVE: To investigate the characteristics of chromosomal abnormalities in amniotic fluid among pregnant women in Liangshan Prefecture and explore strategies for optimizing prenatal diagnosis. METHODS: A retrospective analysis was conducted on 1 024 amniocentesis samples collected at the Prenatal Diagnosis Center of Liangshan Prefecture Maternal and Child Health Care Hospital between February 2022 and December 2024. Chromosome karyotyping analysis (3 cases had failed culture, 1 021 valid samples) was combined with high-throughput chromosome sequencing analysis (CNV-seq) for the detection. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2023-07). RESULTS: The overall detection rate of chromosomal karyotype abnormalities in the amniotic fluid cells was 4.02% (41/1 021), with numerical abnormalities accounting for 80.49% (33/41) and structural abnormalities for 19.51% (8/41). Numerical abnormalities were primarily trisomy 21 (16/41, 39.02%) and 47,XXY (6/41, 14.63%). Structural abnormalities included translocations (6 cases) and mosaicism (2 cases). CNV-seq detected 22 pathogenic or likely pathogenic copy number variations, whilst the undetection rate for balanced translocations reached 100% (7/7). The combined application of karyotyping and CNV-seq, leveraging complementary strengths, can enhance the overall detection rate. CONCLUSION The distribution characteristics of chromosomal abnormalities in amniotic fluid from pregnant women in Liangshan exhibit regional specificity. A combined testing strategy significantly optimizes prenatal diagnosis efficacy, providing crucial evidence for enhancing the effectiveness of prenatal diagnosis in ethnic minority regions.
Humans ; Female ; Pregnancy ; Prenatal Diagnosis/methods* ; Chromosome Aberrations ; Retrospective Studies ; Adult ; Amniotic Fluid ; Karyotyping ; Amniocentesis ; Chromosome Disorders/genetics* ; China ; High-Throughput Nucleotide Sequencing ; DNA Copy Number Variations/genetics*

OBJECTIVES

To validate a method in detecting SARS-CoV-2 via RT-qPCR in pregnant and non-pregnant samples other than nasopharyngeal swabs and/or oropharyngeal swabs such as cervical, rectal, amniotic fluid, placental, umbilical cord blood, and breastmilk.

We performed a validation experiment using MGI easy extraction kits and BGI PCR kits on non-conventional specimens, including cervical, rectal, amniotic fluid, placental, umbilical cord blood, and breastmilk to detect and confirm the presence of SARS-CoV-2. In addition, we tested the validated method on 572 purposively sampled field-collected non-conventional specimens from a cohort of 109 unvaccinated pregnant and 47 unvaccinated non-pregnant women to assess which candidate non-conventional maternal- and fetal-associated specimens may contribute to maternal-fetal viral vertical transmission.

Positive detection of SARS-CoV-2 viral RNA in non-conventional specimens was demonstrated and verified. Of the 572 non-conventional samples tested, 1.8% (10/572) were positively validated by RT-qPCR for SARS-CoV-2 in the maternal-associated specimens particularly the rectal (5), placental (1), and cervical (4) swabs among six pregnant and four non-pregnant individuals. In contrast, no SARS-CoV-2 viral RNA was detected in fetal-associated specimens.

The results of the validation study may serve as an additional diagnostic screening layer to support maternal-child care. Furthermore, viral detection in these non-conventional maternal specimens may also be utilized to provide guidance in the clinical management of neonates, and pregnant women during delivery.

Infant, Newborn ; Female ; Humans ; Amniotic Fluid ; Perinatal Death ; Pneumonia, Aspiration/etiology* ; Arteries

To explore the application value of whole exome sequencing (WES) in the diagnosis of prenatal and postnatal neurodevelopmental disorders (NDDs). A total of 70 patients diagnosed with NDDs who underwent WES at the Medical Genetics Center of the Maternal and Child Health Hospital of Hubei Province between June 2020 and July 2021 were retrospectively analyzed. Genomic DNA was extracted from peripheral blood samples and amniotic fluid. WES-based copy number variant (CNV) analysis was integrated into the routine WES data analysis pipeline. The results showed that a molecular diagnosis rate could be made in 21/70 (30%) cases. Of 21 positive cases, 14 (23%) cases were detected by single-nucleotide variant/small insertion/deletion (SNV/Indel) analysis, of which 12 variants were novel, 6 (9.8%) cases were detected by WES-based CNV analysis, and 1 (1.6%) case was detected by a combination of both. The diagnostic yield of WES combined with CNV analysis was higher than that of SNV/Indel analysis alone (30%, 21/70 vs. 20%, 14/70). Of the 28 prenatally diagnosed cases, 6 cases were found to have inherited parental variation for NDDs, 10 cases were found not to have the same pathogenic variation as the proband, and the remaining 12 cases were found to have no pathogenic or likely pathogenic variation that could explain the NDDs phenotype. Clinical follow-up showed that 5 families opted for abortion and the remaining had no current abnormalities. In conclusion, WES may be an effective method to clarify the genetic etiology and prenatal diagnosis of NDDs, which is helpful in assessing the prognosis to aid clinical management and reproductive guidance.
Pregnancy ; Humans ; Female ; Exome Sequencing ; Retrospective Studies ; Prenatal Diagnosis ; Amniotic Fluid ; Phenotype

OBJECTIVE: To explore the genetic basis for a fetus with club foot detected upon mid-pregnancy ultrasonography. METHODS: Amniotic fluid of the fetus and peripheral blood samples of its parents were collected and subjected to G-banding karyotype analysis and copy number variation sequencing (CNV-seq). The result was verified by fluorescence in situ hybridization (FISH). RESULTS: The fetus and its parents all had a normal karyotype. CNV-seq analysis revealed that the fetus has harbored a 23.12 Mb on chromosome 5 and a 21.46 Mb duplication on chromosome 7. FISH assay has verified that its mother has carried a cryptic t(5;7)(p14.3;q33) translocation. CONCLUSION CNV-seq combined with FISH can effectively detect cryptic chromosome aberrations, and can help to reduce severe birth defects and provide a basis for prenatal genetic counseling.
Pregnancy ; Female ; Humans ; Cri-du-Chat Syndrome ; In Situ Hybridization, Fluorescence ; DNA Copy Number Variations ; Prenatal Diagnosis ; Fetus ; Amniotic Fluid ; Chromosome Deletion

Neonates born through meconium-stained amniotic fluid (MSAF) may develop complications including meconium aspiration syndrome, persistent pulmonary hypertension of newborn and death. The approach to the resuscitation of these neonates has significantly evolved for the past few decades. Initially, under direct visualization technique, neonates with MSAF were commonly suctioned below the vocal cords soon after delivery. Since 2015, Neonatal Resuscitation Program (NRP^®) of the American Academy of Pediatrics has recommended against "routine" endotracheal suctioning of non-vigorous neonates with MSAF but favored immediate resuscitation with positive pressure ventilation via face-mask bagging. However, the China neonatal resuscitation 2021 guidelines continue to recommend routine endotracheal suctioning of non-vigorous neonates born with MSAF at birth. This review article discusses the differences and the rationales in the approach in the resuscitation of neonates with MSAF between Chinese and American NRP^® guidelines over the past 60 years.
Female ; Infant, Newborn ; Humans ; Child ; Meconium Aspiration Syndrome/therapy* ; Meconium ; Resuscitation ; Amniotic Fluid ; Intubation, Intratracheal/methods* ; Infant, Newborn, Diseases ; China

OBJECTIVE: To validate a fetus with high risk for trisomy 13 suggested by non-invasive prenatal testing (NIPT). METHODS: The fetus was selected as the study subject after the NIPT detection at Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences on February 18, 2019. Clinical data of the pregnant woman was collected. Fluorescence in situ hybridization (FISH), chromosomal karyotyping analysis and chromosomal microarray analysis (CMA) were carried out on amniotic fluid and umbilical cord blood and the couple's peripheral blood samples. Copy number variation sequencing (CNV-seq) was also performed on the placental and amniotic fluid samples following induced labor. RESULTS: The pregnant woman, a 38-year-old G4P1 gravida, was found to have abnormal fetal development by prenatal ultrasonography. NIPT test suggested that the fetus has a high risk for trisomy 13. Chromosomal karyotyping analysis of fetal amniotic fluid and umbilical cord blood were 46,XN,add(13)(p10). The result of CMA was arr[hg19]1q41q44(223937972_249224684)×3, with the size of the repeat fragment being approximately 25.29 Mb, the fetal karyotype was thereby revised as 46,XN,der(13)t(1;13)(q41;p10). Chromosomal karyotyping analysis and CMA of the parents' peripheral blood samples showed no obvious abnormality. The CNV-seq analysis of induced placenta revealed mosaicisms of normal karyotype and trisomy 13. The CNV-seq test of induced amniotic fluid confirmed a duplication of chr1:22446001_249220000 region spanning approximately 24.75 Mb, which was in keeping with the CMA results of amniotic fluid and umbilical cord blood samples. CONCLUSION NIPT may yield false positive result due to placenta mosaicism. Invasive prenatal diagnosis should be recommended to women with a high risk by NIPT test. And analysis of placenta can explain the inconsistency between the results of NIPT and invasive prenatal diagnosis.
Humans ; Female ; Pregnancy ; Trisomy 13 Syndrome/genetics* ; DNA Copy Number Variations ; Placenta ; Chromosomes, Human, Pair 1 ; In Situ Hybridization, Fluorescence ; Prenatal Diagnosis/methods* ; Fetus ; Amniotic Fluid ; Chromosome Aberrations ; Trisomy/genetics*

OBJECTIVE: To delineate the origin and content of a mosaicism small supernumerary marker chromosome (sSMC) in a fetus with combined chromosomal karyotyping, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH). METHODS: The fetus of a 31-year-old pregnant woman who had presented at the Maternal and Child Health Care Hospital of Longhua District of Shenzhen City in 2022 was selected as the study subject. Non-invasive prenatal testing suggested that the fetus has harbored a 8.75 Mb duplication in 4q12q13.1. With informed consent, amniotic fluid and peripheral blood samples were taken from the couple for chromosomal karyotyping analysis. The origin and content of a sSMC was identified by CMA, and its proportion in amniotic fluid was determined with a FISH assay. RESULTS: The karyotypes of the pregnant woman, her husband and the fetus were respectively determined as 46,XX, 46,XY,inv(9)(p12q12), and 47,XY,inv(9)(p12q12)pat,+mar[75]/ 46,XY,inv(9)(p12q12)pat[25]. CMA test of the amniotic fluid sample was arr[hg19]4p11q13.1(48978053_63145931)×3, which revealed no mosaicism. However, FISH analysis showed that 59% of interphase cells from the cultured amniotic fluid sample had contained three signals for the centromere of chromosome 4, whilst 65% of interphase cells from the re-sampled amniotic fluid had three such signals, which confirmed the existence of trisomy 8 mosaicism. CONCLUSION Chromosomal structural abnormality combined with mosaicism can be delineated with combined chromosomal karyotyping and molecular techniques such as FISH and CMA, which has enabled more accurate counseling for the family.
Humans ; Child ; Female ; Pregnancy ; Adult ; In Situ Hybridization, Fluorescence ; Mosaicism ; Genetic Techniques ; Amniotic Fluid ; Chromosomes, Human, Pair 4

OBJECTIVE: To assess the value of using flat-sided culture tubes for preparing chromosomes through chorionic villi (CV) and amniotic fluid (AF) cell cultures during prenatal diagnosis. METHODS: From February to March 2020, 157 CV samples and 147 AF samples subjected to prenatal diagnosis at the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region were selected as the study subjects. For each sample, one flat-sided tube and one flask culture were set up by following the standard protocols. The methods were evaluated by comparing the cell growth, experimental process, quality of chromosome preparation and costs. RESULTS: The success rates for the culturing of CV and AF samples by the flat-sided culture tube method were 97.45% (153/157) and 97.96% (144/147), respectively. By contrast, the success rates for the conventional flask method were 98.72% (155/157) for CV and 98.64% (145/147) for AF samples. No significant difference was found between the two methods (P > 0.05). The average harvest time required by the flat-sided culture tube method was 8.45 days for CV and 9.43 days for AF cultures, whilst the average harvest time for conventional flask method was 9.05 days and 9.54 days, respectively. The flat-sided culture tube method for CV had required significantly shorter average harvest time than the conventional method (P < 0.001). No statistical significant difference was found in the average harvest time for AF by the two methods (P > 0.05). The conventional culturing method had required three containers with two sample transfers. By contrast, the flat-sided culture tube method was carried out in one tube without any sample transfer. The average total amount of medium used was 3.91 mL for each flat-sided culture tube and 6.26 mL for each conventional flask. CONCLUSION The flat-sided culture tube method can provide a simple, cost-effective and error-reducing procedure for the CV and AF samples culture during prenatal diagnosis.
Child ; Female ; Pregnancy ; Humans ; China ; Prenatal Diagnosis ; Chorionic Villi Sampling ; Amniotic Fluid ; Cell Proliferation