Lower detectability of non-invasive prenatal testing compared to prenatal diagnosis in high-risk pregnant women

Examination of Risk of Depression and Perception of Social Support in Pregnant Women Undergoing Intrauterine Intervention

BACKGROUND

Interventions during pregnancy might increase the risk of depression becausethey may cause anxiety and stress in the mother. In these cases, it is important to provide social support to pregnant women.

AIM

This study aimed to determine the relationship between the risk of depression and the perception of social support in pregnant women who had undergone intrauterine intervention (IUI).

METHODS

The population of this descriptive study consisted of all pregnant women (n = 267) who attended a state hospital in Izmir between March and September 2022 and who had undergone IUI. Data were obtained using a sociodemographic data form, the Beck Depression Inventory (BDI), and the Multidimensional Scale of Perceived Social Support (MSPSS). Descriptive statistics and the Chi-square test were used in the study.

RESULTS

In this study, of the women, 42.7% had ≥3 pregnancies; the gestational week of 93.6% of the pregnant women was between 13-24 weeks. The mean scores of the pregnant women were 11.12 ± 8.04 on the BDI and 61.06 ± 19.84 on the MSPSS. According to the results of the correlation analysis, there was a weak (<0.05) negative reverse correlation between the scales.

CONCLUSIONS

In the results of this study, it has been determined that as perceived social support increases in pregnant women, symptoms of depression are less likely to occur. This result is important in terms of indicating the need for providing social support to pregnant women. Women should be able to identify depression risk factors during this process to receive appropriate care and support.

Understanding knowledge, perception, and willingness of non-invasive prenatal testing for fetal aneuploidy: a survey among Chinese high-risk pregnant women

Objectives

Non-invasive prenatal testing (NIPT) is utilized for screening the likelihood of fetal aneuploidy, presenting the benefits of non-invasiveness, high sensitivity, and specificity. Its application in prenatal screening has become ubiquitous. The inquiry into how pregnant women comprehend and determine NIPT screening strategies is paramount. Regrettably, there has been a dearth of research on this subject in China. Consequently, this study scrutinizes pregnant women's cognizance and perspectives concerning NIPT, furnishing a foundation for advancing its judicious implementation.

Methods

From February 2021 to December 2022, a questionnaire survey was conducted among pregnant women receiving prenatal care and screening at the Women's Hospital, School of Medicine, Zhejiang University, who were randomly selected from a pool of individuals exhibiting a high risk of fetal aneuploidy on serological screening. The survey aimed to gather data on participant characteristics, knowledge, perception, and willingness concerning NIPT. The study employed chi-square and Kruskal Wallis tests to analyze subgroup differences.

Results

A total of 226 valid questionnaires were obtained. 83.2% of women pregnant women identified as high risk by serological screening would opt for NIPT, with 66.4% indicating that they would prefer NIPT for fetal aneuploidy screening in future pregnancies. These findings suggest a notable willingness among pregnant women to undergo NIPT. Additionally, the results suggest that various factors, including place of residence, educational level, family income, causes of abortion, and conception method, influence pregnant women's knowledge about NIPT Accordingly, the level of NIPT knowledge varies among pregnant women.

Conclusion

The survey generally revealed that pregnant women were strongly inclined to select NIPT; however, expectant Chinese mothers possess limited knowledge and perception regarding this screening method for fetal aneuploidy. Therefore, the government must implement effective measures to augment public awareness of fetal aneuploidy screening and encourage the judicious utilization of NIPT.

Residual risk of noninvasive prenatal screening in pregnancies with ultrasound anomalies

OBJECTIVES

To discuss the residual risk (RR) of noninvasive prenatal screening (NIPS) for the mothers with fetal ultrasound abnormalities.

METHODS

880 pregnant women with fetal ultrasound abnormalities accepted prenatal diagnosis by chromosomal microarray analysis (CMA) after amniocentesis. Furthermore, the detection efficiency of NIPS was evaluated and calculated based on our previous studies and other literatures. The RR of the chromosome abnormality results was then analyzed.

RESULTS

A total of 103 cases were confirmed as fetal chromosome abnormalities, including 65 (63.1%) of aneuploidies and 38 (36.9%) of clinical significant copy number variations (CNVs). Of which, based on the estimated NIPS efficacy, 87 cases could also be detected by NIPS. The detection rate (DR) was 84.5%, while 16 cases would be missed. The total of RR of NIPS in the fetuses with ultrasound anomalies was 2.0% (16/793), approximately one in 51. The top three RR of fetal ultrasound abnormalities were echogenic bowel (5.9%), multiple systems of structural anomalies (4.5%), and nervous system anomalies (4.2%).

CONCLUSION

The overall residual risk of NIPS in the fetuses with ultrasound anomalies was approximately 2.0%, especially in echogenic bowel, multiple systems of structural anomalies and nervous system anomalies.

Enrichment of circulating trophoblasts from maternal blood using filtration-based Metacell® technology

In a cell-based non-invasive prenatal test (cbNIPT), intact circulating trophoblasts (CTs) are isolated from maternal blood for subsequent genetic analysis. Enrichment of these CTs from maternal blood is the most challenging step in the cbNIPT workflow. This study aims to assess the suitability of the filtration-based Metacell® technology to enrich CTs from maternal blood at week 10 to 13 of gestation. The Metacell® technology is a novel size-based enrichment technology that combines blood filtration through 8 μm pores with an in vitro culture method. Three protocols were evaluated. First, 8 mL or 16 mL of maternal blood was filtered and subsequently cultured in vitro on the separation membrane for 3 days in RPMI 1640. In addition, 16 mL of maternal blood was filtered, and immediately processed without further culturing. Y-chromosome-specific qPCR or STR analysis was performed to evaluate the enrichment of CTs. A total of 44 samples from pregnant women, out of which 26 were carrying a male fetus, were processed. Although five enriched male fetus samples show detectable male DNA quantities, it cannot be excluded that the obtained positive signal is caused by cell-free fetal DNA sticking to the Metacell® separation membrane. In conclusion, the Metacell® technology, tested as described, is not suitable for consistent enrichment of CTs.

Is Cell-free fetal DNA testing a safe option for women in a high-risk population after combined first-trimester testing?

OBJECTIVES

Our study aimed to examine the relevance of cell-free fetal DNA (cfDNA) testing on the screening of chromosomal defects and the issue of pregnancies in patients with a risk over 1:50 after the first-trimester combined test.

METHODS

This is a retrospective monocentric study. We included all consecutive patients with a singleton pregnancy between January 2015 and December 2020 attending our fetal medicine centre because the estimated risk for trisomy 21 after the first-trimester combined screening was over 1:50. The patients could either choose to have invasive testing or cell-free DNA testing. We collected data about the patient, the tests results (cfDNA, karyotype) and the pregnancy outcome (born alive, medical termination, miscarriage or intrauterine fetal death).

RESULTS

We included 98 patients with an estimated risk for trisomy 21 over 1:50. We found a total of 14 major chromosomal abnormalities (14/98; 14.3%), of which: thirteen trisomies 21 and one triploidy 69, XXY. A cfDNA testing was chosen by 34 (34/98; 34.7%) patients. Among the pathological results of invasive testing, 5 (5/64; 7.8%) couldn't be targeted by cfDNA testing. Two of them were placental mosaicism, one a triploidy 69, XXY, and two defects inherited from a parent and considered benign. There was no miscarriage linked to an invasive test in the population study.

CONCLUSION

In our monocentric cohort, a third of the patients choose cfDNA in a case of a risk over 1:50 after combined testing. Even if this cohort is too small to draw definitive conclusions, cfDNA could be safe in a high-risk population after combined testing. None of the chromosomal abnormalities found at the karyotype and non-detectable by cfDNA was a loss of information that impacted pregnancy follow-up. Further study could explore the input of Genome-Wide cfDNA and chromosomal micro-array in this population.

Assessment and Clinical Utility of a Non-Next-Generation Sequencing-Based Non-Invasive Prenatal Testing Technology

Background: Rolling-circle replication (RCR) is a novel technology that has not been applied to cell-free DNA (cfDNA) testing until recently. Given the cost and simplicity advantages of this technology compared to other platforms currently used in cfDNA analysis, an assessment of RCR in clinical laboratories was performed. Here, we present the first validation study from clinical laboratories utilizing RCR technology. Methods: 831 samples from spontaneously pregnant women carrying a singleton fetus, and 25 synthetic samples, were analyzed for the fetal risk of trisomy 21 (T21), trisomy 18 (T18) and trisomy 13 (T13), by three laboratories on three continents. All the screen-positive pregnancies were provided post-test genetic counseling and confirmatory diagnostic invasive testing (e.g., amniocentesis). The screen-negative pregnancies were routinely evaluated at birth for fetal aneuploidies, using newborn examinations, and any suspected aneuploidies would have been offered diagnostic testing or confirmed with karyotyping. Results: The study found rolling-circle replication to be a highly viable technology for the clinical assessment of fetal aneuploidies, with 100% sensitivity for T21 (95% CI: 82.35-100.00%); 100.00% sensitivity for T18 (71.51-100.00%); and 100.00% sensitivity for T13 analyses (66.37-100.00%). The specificities were >99% for each trisomy (99.7% (99.01-99.97%) for T21; 99.5% (98.62-99.85%) for T18; 99.7% (99.03-99.97%) for T13), along with a first-pass no-call rate of 0.93%. Conclusions: The study showed that using a rolling-circle replication-based cfDNA system for the evaluation of the common aneuploidies would provide greater accuracy and clinical utility compared to conventional biochemical screening, and it would provide comparable results to other reported cfDNA methodologies.

The Optimal Cutoff Value of Z-scores Enhances the Judgment Accuracy of Noninvasive Prenatal Screening

Objective

To evaluate the accuracy of Z-scores of noninvasive prenatal screening (NIPS) in predicting 21, 18 trisomy, and X chromosome aneuploidy.

Methods

A total of 39,310 prenatal women were recruited for NIPS from September 2015 to September 2020. Interventional prenatal diagnosis was applied to verify the diagnosis of NIPS-positive results. Logistic regression analysis was employed to relate the Z-scores to the positive predictive value (PPV) of NIPS-positive results. Using receiver operating characteristic (ROC) curves, we calculated the optimal cutoff value of Z-scores to predict fetal chromosome aneuploidy. According to the cutoff value, NIPS-positive results were divided into the medium Z-value (MZ) and high Z-value (HZ) groups, and PPV was calculated to access the accuracy of Z-scores.

Results

A total of 288 effective values of Z-scores were used as the final data set. The logistics regression analysis revealed that Z-scores were significantly associated with true-positive results for 21 trisomy (T21) and 18 trisomy (T18) (P < 0.05), whereas the same was not observed for X chromosome aneuploids (P > 0.05). The optimal cutoff value of the Z-score for T21, T18, XO, XXX, and XXY indicated by ROC curve analysis were 5.79, 6.05, −9.56, 5.89, and 4.47, and the area under the curve (AUC) were 0.89, 0.80, 0.48, 0.42, and 0.45, respectively. PPV in the HZ group was higher than that in the MZ group, and the application of the cutoff value reduced the false discovery rate (FDR), which was only 2.9% in the HZ group compared with 61.1% in the MZ group for T21 and T18. The difference in total PPV between the MZ and HZ groups for X chromosome aneuploids was statistically significant. Moreover, the PPV for XXX and XXY seemed to increase with Z-scores but not for XO.

Conclusion

The Z-score is helpful for the accurate judgment of NIPS results and for clinical prenatal counseling. Especially for T21 and T18, Z-scores have an excellent clinical association, which is superior to that seen with X chromosome aneuploids. In addition, using Z-scores to judge NIPS results offers a certain reference value for XXX and XXY but not for XO.

Prenatal diagnosis of cri-du-chat syndrome by SNP array: report of twelve cases and review of the literature

Background

Cri-du-chat syndrome (CdCS; OMIM#123450) is a classic contiguous gene syndrome caused by chromosome 5p terminal deletion (5p-), which characterized by a high-pitched cat-like cry, developmental delay, severe psychomotor, mental retardation, and dysmorphic features in infancy. Prenatal diagnosis of CdCS is difficult due to the non-specific ultrasound features. And reports using array analysis are rare. This study presented the first retrospective analysis of prenatal series of CdCS fetuses diagnosed by single nucleotide polymorphism (SNP) array in China.

Case presentation

A total of 35,233 pregnant women were enrolled from Jan 2014 to April 2019 in our center, there are twelve 5p- cases with abnormal sonographic signs revealed by SNP array, giving an incidence of 0.034% (12/35,233). Clinical information and molecular basis included: maternal demographics, indications for invasive testing, sonographic findings and SNP array results. Among all the 5p- cases revealed, nine cases were diagnosed by both karyotyping and SNP array, three cases were detected only by SNP array. Half of our cases (6/12) had an isolated 5p terminal deletion, which sizes ranged from 9.0 Mb to 30 Mb. The other half of cases (6/12) characterized by unbalanced translocation, with sex ratio 7:5 (female: male), when combine the clinical features observed from this study and available literature, the most frequent anomaly observed in prenatal ultrasound examination of CdCS was cerebral abnormalities, accounted for 44.4% (16/36) of the existing cases. Features that are less consistent included: choroid plexus cyst (13.8%, 5/36), single umbilical artery (13.3%, 4/30), ventricular septal defect (11.1%, 4/36), hydrops fetalis (8.3%, 3/36), ascites (8.3%, 3/36), increased NT/NF (8.3%, 3/36), absent/severely hypoplastic nasal bone (5.5%, 2/36), in order.

Conclusion

Prenatal findings such as cerebral abnormalities, absent/hypoplastic nasal bone, hydrops fetalis, ascites or encephalocele may act as suggestive signs of CdCS or other microdeletion/duplication syndromes. Combining typical karyotyping with chromosomal microarray analysis (CMA) is a definitive method for a precise diagnosis of CdCS and provides more accurate results in order to offer genetic counseling to families which need to deal with cryptic aberrations.