Non-invasive prenatal testing (NIPT) based on fetal free DNA is a non-invasive technique to screen for common fetal aneuploidies by analyzing cell-free fetal DNA (cffDNA) in the peripheral blood of pregnant women. This technique has opened a new era of prenatal screening for its high safety and reliability. In recent years, it has been shown that NIPT can not only screen for fetal aneuploidies, but may also reveal maternal genomic abnormalities. The incidental detection of maternal tumors has aroused widespread concern in the clinical settings. The aim of this review is to systematically summarize the research progress of NIPT technique in incidental detection of maternal tumors, and to discuss its clinical significance, technical challenges, and future development direction. It has been found that multiple chromosome aneuploidies (MCAs) in NIPT detection is one of the important biomarkers suggesting occult maternal malignant tumors. In this paper, the relevant progress of NIPT technique in the incidental discovery of maternal tumors were reviewed in order to provide a reference for individualized and standardized application of NIPT technique in maternal health monitoring.
Humans ; Female ; Pregnancy ; Cell-Free Nucleic Acids/blood* ; Prenatal Diagnosis/methods* ; Incidental Findings ; Neoplasms/genetics* ; Noninvasive Prenatal Testing/methods* ; Aneuploidy ; Fetus/metabolism*

OBJECTIVE: To analyze the chromosome status of pre-implantation embryos from women of different ages, and assess the impact of age on it. METHODS: A retrospective analysis was carried out on the results of PGT-A and PGT-M+PGT-A cycles by whole-genome amplification followed by next generation sequencing at the Second People's Hospital of Nanning between July 2021 and November 2023. The embryos were divided into five groups based on the women's age: ≤ 30 years old group, 31 ~ 34 years old group, 35 ~ 37 years old group, 38 ~ 40 years old group, and ≥ 41 years old group.The chromosomal status of embryos for each group was compared. This study has been approved by the Ethic Committee of the Hospital (Ethics No. Y2024312A). RESULTS: This study has involved 390 couples and 436 PGT cycles, with a total of 1 651 blastocysts biopsied and analyzed. Among these, 835 embryos (50.6%) were found to have chromosomal abnormalities, including 490 (29.7%) with aneuploidies, 154 (9.3%) with chromosomal segment abnormalities, and 264 (16.0%) with chromosome mosaicisms. After adjusting the dosages of Gn, female BMI, male age, PGT indications, infertility type, LH, AMH and other parameters, maternal age appeared to be an independent factor for chromosomal abnormalities and aneuploidies in blastocysts (OR = 1.132, 95%CI = 1.089-1.177, P < 0.001; OR = 1.250, 95%CI = 1.188-1.315, P < 0.001). With the increase in female age, embryonic chromosome abnormalities have significantly increased in each group, with the rates being 32.3% (126/390), 43.1% (189/439), 45.1% (116/257), 66.3% (250/377), and 81.9% (154/188) (P < 0.001). Chromosomal aneuploidies have also significantly increased, with the rates being 8.2% (32/390), 16.6% (73/439), 24.5% (63/257), 49.6% (187/377), and 71.8% (135/188) (P < 0.001). The proportion of embryos with ≥ 2 chromosome abnormalities also significantly increased in abnormal embryos, with the rates being 28.6% (36/126), 30.2% (57/189), 39.7% (46/116), 48.4% (121/250), and 64.9% (100/154) (P < 0.001). Of note, the female age did not affect the prevalence of chromosomal segment abnormalities and mosaicisms (all P > 0.05). CONCLUSION Above findings suggested that along with the increase in female age, there is an increase in the rate and complexity of chromosomal abnormalities, which may contribute to infertility in women with elder age.
Humans ; Female ; Maternal Age ; Adult ; Retrospective Studies ; Chromosome Aberrations ; Preimplantation Diagnosis/methods* ; Pregnancy ; Blastocyst/metabolism* ; Aneuploidy ; Fertilization in Vitro ; Male

OBJECTIVE: To explore the genetic etiology of two fetuses with Mosaic variegated aneuploidy syndrome (MVA) in a pedigree. METHODS: A 30-year-old pregnant woman, who presented at the Center for Medical Genetics and Prenatal Diagnosis of Shandong Maternal and Child Health Care Hospital on November 16, 2023, was enrolled. Clinical data of the pedigree were collected, and peripheral blood samples from the parents and amniotic fluid samples from the two fetuses were obtained for genomic DNA extraction. Whole exome sequencing (WES) was performed on both fetuses, followed by Sanger sequencing for familial validation and pathogenicity analysis of candidate variants. Chromosomal karyotyping of the parents was conducted to quantify the proportion of premature chromatid separation (PCS). This study was approved by the Medical Ethics Committee of Shandong Maternal and Child Health Care Hospital (Ethics No. 2024-034). RESULTS: Both fetuses exhibited structural brain anomalies and developmental delays during the second trimester. Amniocyte karyotyping revealed low-level mosaic aneuploidy involving multiple chromosomes, while chromosomal microarray analysis (CMA) showed no abnormalities. Pregnancy termination was performed for fetus 1. WES identified compound heterozygous variants in BUB1B, i.e., c.2363_2364del (p.S788Cfs*29) and ss804270619: G>A, in both fetuses. Sanger sequencing confirmed paternal inheritance of c.2363_2364del and maternal inheritance of ss804270619:G>A. According to the American College of Medical Genetics and Genomics (ACMG) and Clinical Genome Resource (ClinGen) Standards and Guidelines for the Interpretation of Sequence Variants, the c.2363_2364del variant was classified as likely pathogenic (PVS1 + PM2_Supporting). Parental karyotyping demonstrated PCS traits, with a higher proportion of abnormal metaphases in the father. CONCLUSION The compound heterozygous variants c.2363_2364del (p.S788Cfs*29) and ss804270619: G>A in BUB1B may constitute the genetic etiology of the two MVA fetuses in this pedigree.
Humans ; Female ; Pregnancy ; Adult ; Mosaicism ; Protein Serine-Threonine Kinases/genetics* ; Chromosome Disorders/diagnosis* ; Pedigree ; Heterozygote ; Prenatal Diagnosis ; Aneuploidy ; Male ; Fetus ; Karyotyping

OBJECTIVE: To analyze the results of prenatal diagnosis for fetuses with a high risk for sex chromosome aneuploidies (SCAs) indicated by non-invasive prenatal testing (NIPT), and to assess the influence of maternal chromosomal factors on the results of NIPT. METHODS: A retrospective analysis was conducted on the clinical data of 454 pregnant women with a high risk for SCAs indicated by NIPT undergoing invasive prenatal diagnosis at the Medical Genetics Center of Northwest Women's and Children's Hospital from January 2022 to September 2024. The data has included prenatal diagnosis indications, results, pregnancy outcomes, and the chromosomal results of pregnant women. RESULTS: Among the 454 women (including 10 with twin pregnancy) with a high risk for SCAs indicated by NIPT, 149 (including 4 twin cases) were diagnosed with SCAs through invasive prenatal diagnosis. These had included 47,XXX (37 cases), 47,XXY (56 cases), 47,XYY (29 cases), 45,X (1 case), 48,XXYY (1 case), mosaicism (20 cases), sex chromosome structural abnormalities (6 cases), and small-scale pathogenic copy number variations (3 cases). 383 pregnant women (including 7 with twin pregnancy) had accepted chromosomal karyotyping analysis. In total 49 cases of SCAs abnormalities were detected. Among them, 41 cases were pregnant women with SCAs but normal fetal chromosomes, which yielded a false positive rate for NIPT caused by maternal factors by 10.7%. In addition, 8 cases (including 1 twin case) had SCAs abnormalities in both the pregnant woman and the fetus. Among the 383 pregnant women, 129 cases (including 3 twin cases) of fetal SCAs were diagnosed, which yielded an overall positive predictive value (PPV) of NIPT for SCAs by 33.7% (129/383). With the 41 false positive cases caused by maternal SCAs abnormalities excluded, the PPV of NIPT for SCAs will be increased to 37.7% (129/342). Among the 454 pregnant women, twin pregnancies have accounted for 2.2% (10/454). Among the confirmed cases of SCAs abnormalities, twin cases accounted for 2.7% (4/149). Among the 383 pregnant women undergoing chromosomal karyotyping, twin cases accounted for 1.8% (7/383). Among the detected cases of chromosomal abnormalities, twin cases accounted for 2.0% (1/49). By calculation, the proportion of singleton pregnant women with a high risk for SCAs indicated by NIPT was approximately 32.1%, and the proportion of twin pregnant women was approximately 38.6%, indicating that twin pregnancies could increase the positive rate of NIPT. CONCLUSION NIPT can improve the screening efficiency for SCAs, but its PPV is limited. Therefore, pregnant women with a high risk for SCAs indicated by NIPT need to undergo invasive prenatal diagnosis for a definite diagnosis, and twin pregnancies can increase the positive rate of NIPT. The study confirmed that chromosomal abnormalities in pregnant women can significantly affect the accuracy of NIPT in detecting fetal SCAs. Therefore, when NIPT indicates SCAs abnormalities, it is recommended to simultaneously conduct chromosomal testing on the pregnant women. The combined application of chromosomal karyotyping analysis, fluorescence in situ hybridization, and copy number variation detection techniques can significantly improve the diagnostic accuracy for SCAs, especially for the detection of mosaicisms.
Humans ; Female ; Pregnancy ; Sex Chromosome Aberrations ; Adult ; Retrospective Studies ; False Positive Reactions ; Prenatal Diagnosis/methods* ; Noninvasive Prenatal Testing/methods* ; Aneuploidy ; Male ; Sex Chromosome Disorders/genetics*

OBJECTIVE: To assess the clinical value of digital PCR (dPCR) for the prenatal diagnosis of common fetal aneuploidies. METHODS: A dPCR-based assay was developed for detecting trisomies 21, 18, and 13. A retrospective analysis was carried out on 173 amniotic fluid samples collected by the Prenatal Diagnosis Center of Taizhou Hospital between January 2017 and December 2023. By using chromosomal karyotyping as the gold standard, the diagnostic performance of the multiplex dPCR system was evaluated in a double-blind manner. This study has been approved by the Ethics Committee of Taizhou Hospital (Ethics No. K20250339). RESULTS: Chromosomal karyotyping has identified 59 cases of trisomy 21, 5 cases of trisomy 18, 2 cases of trisomy 13, 6 cases with chromosomal structural abnormalities or mosaicisms, and 101 cases with a normal karyotype. The dPCR results (Z-score cutoff = 4.0, CI = 99.997%) showed full concordance with karyotyping (sensitivity = 100%, specificity = 100%, Kappa = 1). Among the 6 structurally abnormal or mosaicism samples, dPCR has accurately detected 4 cases, but mis-classified 2 cases of trisomy 21 with very low-level mosaicisms (3.3%, 6.9%, respectively) as normal. CONCLUSION The established multiplex dPCR system demonstrated high diagnostic accuracy for common chromosomal aneuploidies, with results available within 24 hours. It can serve as an efficient supplementary tool to conventional chromosomal karyotyping, providing reliable support for time-sensitive clinical decision-making in prenatal diagnosis.
Humans ; Female ; Pregnancy ; Aneuploidy ; Prenatal Diagnosis/methods* ; Karyotyping ; Retrospective Studies ; Polymerase Chain Reaction/methods* ; Chromosome Disorders/genetics* ; Adult ; Trisomy 13 Syndrome/diagnosis* ; Trisomy 18 Syndrome/genetics* ; Down Syndrome/genetics*

OBJECTIVE: To block family transmission of a small fragment copy number variation (CNV) with combined 1 Mb resolution preimplantation genetic testing for aneuploidy (PGT-A) and target region preimplantation genetic testing for monogenic disease (PGT-M) strategies. METHODS: A couple who attended the Reproductive and Genetic Medicine Center of Dalian Women and Children's Medical Center (Group) in 2024 were selected as the study subject. Upon the woman's two pregnancies, ultrasound examination revealed fetal abnormalities, and CNV-seq based on low-depth whole genome sequencing revealed that both fetuses had carried a maternal 17p12 microduplication of approximately 1.43 Mb. Microduplication in this region has been associated with Charcot-Marie-Tooth disease type 1A. In view of the fact that the resolution of conventional PGT-A detection cannot meet the requirement of small fragment CNV analysis, and conventional PGT-M assay cannot directly determine the CNV, two detection schemes were adopted. On the one hand, PGT-A testing with 1 Mb resolution was performed on the embryo to directly determine whether it carries the above microduplication. At the same time, the couple and their fetus were subjected to chromosomal typing scheme for the 17p12 region to indirectly identify embryos carrying the risk chromosome for microduplication. This study has been approved by the Medical Ethics Committee of the Hospital (Ethics No: FEJT-KY-2025-51). RESULTS: Three embryos were tested after the first PGT cycle, of which 1 was not carrying the pathogenic variant and was euploid, whilst the other 2 embryos were carrying the 17p12 microduplication, and 1 of them was aneuploid. After genetic counseling, the euploid embryo without the 17p12 microduplication was selected for transfer, and prenatal diagnosis based on amniotic fluid sample showed that the fetal chromosomal karyotype was normal and did not carry the 17p12 microduplication. CONCLUSION The combined application of high-resolution PGT-A and PGT-M typing detection of the target region can effectively block family transmission of the CNVs of small fragments.
Humans ; Female ; DNA Copy Number Variations/genetics* ; Preimplantation Diagnosis/methods* ; Pregnancy ; Pedigree ; Genetic Testing/methods* ; Male ; Adult ; Aneuploidy ; Chromosomes, Human, Pair 17/genetics* ; China ; East Asian People

Pregnancy ; Female ; Humans ; Mosaicism ; Prenatal Diagnosis ; Prenatal Care ; Aneuploidy

OBJECTIVE: To assess the clinical efficacy and health economic value of non-invasive prenatal testing (NIPT) for the prenatal screening of common fetal chromosomal aneuploidies. METHODS: 10 612 pregnant women from October 2017 to December 2019 presented at the antenatal screening clinic of the General Hospital of Tianjin Medical University were selected as the study subjects. Results of NIPT and invasive prenatal diagnosis and follow-up outcome for the 10 612 pregnant women were retrospectively analyzed and compared. Meanwhile, NIPT data for two periods were analyzed for assessing the health economic value of NIPT as the second- or first-tier screening strategy for the prenatal diagnosis of fetal trisomies 21, 18 and 13. RESULTS: The NIPT was successful in 10 528 (99.72%) subjects, with the sensitivity for fetal trisomies 21, 18 and 13 being 100%, 92.86% and 100%, and the positive predictive value (PPV) being 89.74%, 61.90% and 44.44%, respectively. The PPV of NIPT for sex chromosome aneuploidies was 34.21%. Except for one false negative case of trisomy 18, the negative predictive value for trisomy 21, trisomy 13 and other chromosomal abnormalities were 100%. For pregnant women with high risk by serological screening, advanced maternal age or abnormal ultrasound soft markers, NIPT has yielded a significantly increased high risk ratio. There was no statistical difference in the PPV of NIPT among pregnant women from each subgroup. NIPT would have higher health economic value as a second-tier screening until 2019, while compared to 2015 ~ 2017, its incremental cost-effectiveness ratio as a first-tier screening had declined clearly. CONCLUSION The screening efficacy of NIPT for trisomies 21, 18 and 13 for a mixed population is significantly better than conventional serological screening, but it is relatively low for sex chromosomal abnormalities. NIPT can also be recommended for populations with relatively high risks along with detailed pre- and post-test genetic counselling. From the perspective of health economics, except for open neural tube defects, it is possible for NIPT to replace the conventional serological screening in the future as its cost continues to decrease.
Pregnancy ; Female ; Humans ; Trisomy/genetics* ; Retrospective Studies ; Prenatal Diagnosis/methods* ; Down Syndrome/genetics* ; Aneuploidy ; Chromosome Aberrations ; Trisomy 18 Syndrome/genetics* ; Sex Chromosome Aberrations ; Fetus

OBJECTIVE: To carry out preimplantation genetic testing for monogenic/single gene disorders (PGT-M) for a Chinese family affected with Molybdenum co-factor deficiency due to pathogenic variant of MOCS2 gene. METHODS: A family with molybdenum co-factor deficiency who attended to the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region in April 2020 was selected as the research subject. Trophoblast cells were biopsied from blastocysts fertilized by intracytoplasmic sperm injection. Embryos carrying the MOCS2 gene variant and chromosome copy number variation (CNV) of more than 4 Mb were detected by single-cell whole genome amplification, high-throughput sequencing and single nucleotide polymorphism typing. Embryos without or carrying the heterozygous variant and without abnormal chromosome CNV were transplanted. During mid-pregnancy, amniotic fluid sample was collected for prenatal diagnosis to verify the results of PGT-M. RESULTS: Eleven oocytes were obtained, among which three blastocysts were formed through culturing. Results of genetic testing suggested that one embryo was heterozygous for the maternally derived MOCS2 gene variant and without chromosomal CNV. Following embryo transfer, intrauterine singleton pregnancy was attained. Prenatal diagnosis by amniocentesis at 18 weeks of gestation revealed that the MOCS2 gene variant and chromosomal analysis results were both consistent with that of PGT-M, and a healthy male infant was born at 37⁺⁵ weeks of gestation. CONCLUSION PGT-M has helped the couple carrying the MOCS2 gene variant to have a healthy offspring, and may become an important method for couples carrying other pathogenic genetic variants.
Female ; Humans ; Pregnancy ; Aneuploidy ; China ; DNA Copy Number Variations ; Genetic Testing/methods* ; Preimplantation Diagnosis/methods* ; Metal Metabolism, Inborn Errors/genetics*

OBJECTIVE: To assess the value of single sperm sequencing in preimplantation genetic testing for monogenic disease (PGT-M). METHODS: A Chinese couple with two children whom had died of Spinal muscular atrophy (SMA) and attended the Jiangxi Provincial Maternal and Child Health Care Hospital in June 2020 was selected as the subject. Eleven single sperm samples were isolated by mechanical immobilization and subjected to whole genome amplification. Real-time PCR and Sanger sequencing were used to detect the SMN1 variants in the single sperm samples. Genomic DNA of the wife, her parents and the husband, as well as one single sperm sample harboring the SMN1 variant and two single sperm samples without the variant were used for the linkage analysis. Targeted capture and high-throughput sequencing were carried out to test 100 single nucleotide polymorphisms distributed within 2 Mb up- and downstream the variant site. The haplotypes linked with the SMN1 variants were determined by linkage analysis. Blastocyst embryos were harvested after fertilizing by intracytoplasmic sperm injection. Cells from the trophoblasts of each embryo were biopsied and subjected to whole genome amplification and targeted capture and high-throughput sequencing to determine their carrier status. Chromosomal aneuploidy of wild-type embryos was excluded. An euploid embryo of high quality was transferred. Amniotic fluid sample was taken at 18 weeks of gestation to confirm the status of the fetus. RESULTS: Genetic testing showed that the couple both had deletion of exons 7 ~ 8 of the SMN1 gene. The wife has inherited the deletion from her father, while the husband was de novo. The haplotypes of the husband were successfully constructed by single sperm sequencing. Preimplantation genetic testing has indicated that 5 embryos had harbored the heterozygous variant, 4 embryos were of the wild type, among which 3 were euploid. Prenatal diagnosis during the second trimester of pregnancy has confirmed that the fetus did not carry the deletion. CONCLUSION By single sperm sequencing and PGT-M, the birth of further affected child has been successfully avoided.
Humans ; Pregnancy ; Female ; Child ; Male ; Preimplantation Diagnosis ; East Asian People ; Semen ; Genetic Testing ; Muscular Atrophy, Spinal/genetics* ; Aneuploidy ; Blastocyst/pathology* ; High-Throughput Nucleotide Sequencing ; Spermatozoa