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

OBJECTIVE: To explore the genetic etiology and related factors in 1 065 women with spontaneous abortions. METHODS: All patients have presented at the Center of Prenatal Diagnosis of Nanjing Drum Tower Hospital from January 2018 to December 2021. Chorionic villi and fetal skin samples were collected, and the genomic DNA was assayed by chromosomal microarray analysis (CMA). For 10 couples with recurrent spontaneous abortions but normal CMA results for abortive tissues, non-in vitro fertilization-embryo transfer (IVF-ET) pregnancies and no previous history of live births and no structural abnormalities of the uterus, peripheral venous blood samples were collected. Genomic DNA was subjected to trio-whole exome sequencing (trio-WES). Candidate variants were verified by Sanger sequencing and bioinformatics analysis. Multifactorial unconditional logistic regression analysis was carried out to analyze the factors that may affect chromosomal abnormality in spontaneous abortions, such as the age of the couple, number of previous spontaneous abortions, IVF-ET pregnancy and history of live birth. The incidence of chromosomal aneuploidies in spontaneous abortions during the first trimester was compared in young or advanced-aged patients by chi-square test for liner trend. RESULTS: Among the 1 065 spontaneous abortion patients, 570 cases (53.5%) of chromosomal abnormalities were detected in spontaneous abortion tissues, which included 489 cases (45.9%) of chromosomal aneuploidies and 36 cases (3.4%) of pathogenic/likely pathogenic copy number variations (CNVs). Trio-WES results have revealed one homozygote variant and one compound heterozygote variants in two pedigrees, both of which were inherited from the parents. One likely pathogenic variant was detected in the patient from two pedigrees. Multifactorial unconditional Logistic regression analysis suggested that age of patient was an independent risk factor of chromosome abnormalities (OR = 1.122, 95%CI: 1.069-1.177, P < 0.001), the number of previous abortions and IVF-ET pregnancy were independent protective factors for chromosomal abnormalities (OR = 0.791, 0.648; 95%CI: 0.682-0.916, 0.500-0.840; P = 0.002, 0.001), whilst the age of husband and history of live birth were not (P > 0.05). The incidence of aneuploidies in the abortive tissues has decreased with the number of previous spontaneous abortions in young patients (χ² = 18.051, P < 0.001), but was not significantly correlated with the number of previous spontaneous abortions in advanced-aged patients with spontaneous abortions (P > 0.05). CONCLUSION Chromosomal aneuploidy is the main genetic factor for spontaneous abortion, though CNVs and genetic variants may also underlie its genetic etiology. The age of patients, number of previous abortions and IVF-ET pregnancy are closely associated with chromosome abnormalities in abortive tissues.
Pregnancy ; Humans ; Female ; Aged ; Abortion, Spontaneous/genetics* ; DNA Copy Number Variations ; Chromosome Aberrations ; Chromosome Disorders/genetics* ; Aneuploidy ; Abortion, Habitual/genetics*

OBJECTIVE: To analyze the result of prenatal diagnosis and outcome of pregnancy for fetuses with rare autosomal trisomies (RATs) suggested by non-invasive prenatal testing (NIPT). METHODS: A total of 69 608 pregnant women who underwent NIPT at Genetics and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from January 2016 to December 2020 were selected as study subjects. The result of prenatal diagnosis and outcome of pregnancy for those with a high risk for RATs were retrospectively analyzed. RESULTS: Among the 69 608 pregnant women, the positive rate of NIPT for high-risk RATs was 0.23% (161/69 608), with trisomy 7 (17.4%, 28/161) and trisomy 8 (12.4%, 20/161) being the most common, and trisomy 17 (0.6%, 1/161) being the rarest. For 98 women who had accepted invasive prenatal diagnosis, 12 fetal chromosomal abnormalities were confirmed, and in 5 cases the results were consistent with those of NIPT, which yielded a positive predictive value of 5.26%. Among the 161 women with a high risk for RATs, 153 (95%) were successfully followed up. 139 fetuses were ultimately born, with only one being clinically abnormal. CONCLUSION Most women with a high risk for RATs by NIPT have good pregnancy outcomes. Invasive prenatal diagnosis or serial ultrasonography to monitor fetal growth, instead of direct termination of pregnancy, is recommended.
Pregnancy ; Female ; Humans ; Trisomy/genetics* ; Pregnancy Outcome ; Retrospective Studies ; Prenatal Diagnosis/methods* ; Fetus ; Trisomy 18 Syndrome/genetics* ; Aneuploidy

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) and trio-whole exome sequencing (trio-WES) for fetuses with increased nuchal translucency (NT) thickness. METHODS: Sixty two pregnant women who had visited Urumqi Maternal and Child Care Health Hospital between June 2018 and June 2020 for NT ≥ 3.0 mm at 11 ~ 13⁺⁶ gestational weeks were selected as study subjects. Relevant clinical data were collected. The patients were divided into 3.0 ~ ＜3.5 mm (n = 33) and ≥3.5 mm groups (n = 29). Chromosome karyotyping analysis and chromosomal microarray analysis were carried out. And trio-WES analysis was performed on 15 samples with NT thickening but negative CMA results. The distribution and incidence of chromosomal abnormalities in the two groups were compared by using chi-square test. RESULTS: The median age of the pregnant women was 29 years old (22 ~ 41 years old), the median thickness of NT was 3.4 mm (3.0 ~ 9.1 mm), and the median gestational age at the detection was 13⁺⁴ weeks (11⁺⁵ ~ 13⁺⁶ weeks). Chromosome karyotyping analysis has detected 12 cases of aneuploidies and 1 case of derivative chromosome. The detection rate was 20.97% (13/62). CMA has detected 12 cases of aneuploidies, 1 case of pathogenic CNV and 5 cases of variant of uncertain significance (VUS), with a detection rate of 29.03% (18/62). The aneuploidy rate for the NT ≥ 3.5 mm group was higher than that for the 3.0 ≤ NT < 3.5 mm group [3.03% (1/33) vs. 41.38% (12/29), χ² = 13.698, P < 0.001]. There was no statistically significant difference between the two groups in the detection rate of fetal pathogenic CNV and VUS (χ² = 0.028, P > 0.05). Trio-WES analysis of 15 samples with negative CMA result and no structural abnormality has identified 6 heterozygous variants, including SOS1: c.3542C>T (p.A1181V) and c.3817C>G (p.L1273V), COL2A1: c.436C>T (p.P146S) and c.3700G>A (p.D1234N), LZTR1: c.1496T>C (p.V499A), and BRAF: c.64G>A (p.D22N), respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), all of the variants were rated as VUS. CONCLUSION NT thickening can indicate chromosome abnormality, and CMA and trio-WES may be used for the prenatal diagnosis.
Pregnancy ; Humans ; Female ; Adult ; Infant ; Nuchal Translucency Measurement/methods* ; Prenatal Diagnosis/methods* ; Chromosome Aberrations ; Aneuploidy ; Fetus/diagnostic imaging* ; Ultrasonography, Prenatal ; DNA Copy Number Variations ; Transcription Factors

Chromosomal mosaicism (CM) is a common phenomenon in preimplantation genetic testing (PGT). In embryos with CM, genetic contents of trophoblastic ectodermal (TE) cells may be different from that of the inner cell mass (ICM) which will develop into the fetus. Embryos with low mosaic proportion could give rise to healthy live births after transplantation, but are accompanied with high pregnancy risks such as high abortion rate. In order to provide a more comprehensive understanding for CM embryos, this article has systematically summarized the recent progress of research on the definition, mechanism, classification, PGT techniques, self-correction mechanism, transplantation outcome and treatment principles for CM embryos.
Pregnancy ; Female ; Humans ; Preimplantation Diagnosis/methods* ; Mosaicism ; Aneuploidy ; Genetic Testing/methods* ; Blastocyst