Procedure-related risk of miscarriage following amniocentesis and chorionic villus sampling: a systematic review and meta-analysis

Pregnancy outcomes of fetuses with congenital heart disease after a prenatal diagnosis with chromosome microarray

OBJECTIVE

To evaluate the pregnancy outcomes of fetuses with congenital heart disease (CHD) after chromosome microarray (CMA)-based prenatal diagnosis.

METHOD

Amniocentesis was performed in 1035 pregnant women carrying fetuses with CHD between September 2014 and December 2019. Chromosomal aberrations in fetuses with CHD were evaluated using CMA. The pregnancy outcomes were followed up from 6 months to 5 years.

RESULTS

The overall CHD detection rate by CMA was 10.1% (105/1035; 50 fetuses: aneuploidy, 55 fetuses: pathogenic or likely pathogenic copy number variations). Among 1003 fetuses who were followed up, 4, 236, 763, and 18 cases were of miscarriages, pregnancy termination, live births, and postnatal deaths, respectively. Self-healed CHD was observed in 401 (52.6%) fetuses. The pregnancy termination rate of fetuses with chromosomal anomalies was significantly higher than that of fetuses without chromosomal anomalies (93.1% vs. 15.5%, p < 0.001). However, other pregnancy outcomes, including mortality, preterm labor, and low-weight birth rate, were similar between the two groups.

CONCLUSION

The outcome of CMA is an important factor influencing parents' choice of whether to continue the pregnancy. Self-healing rate of prenatal diagnosed CHD is high. The mortality and morbidity of fetuses with CHD following prenatal CMA testing are relatively low.

Primary toxoplasmosis acquired during early pregnancy: Is it currently overestimated?

OBJECTIVE

Toxoplasmosis acquired in early pregnancy is a potentially severe complication for the fetus. Evaluating the risk of transplacental infection in pregnant women accessing the Tuscany Reference Center for Infectious Diseases in Pregnancy during the last 20 years with suspected or confirmed toxoplasmosis acquired in early pregnancy was the aim of the study.

STUDY DESIGN

We retrospectively enrolled all pregnant women undergoing amniocentesis for toxoplasmosis acquired in the first 16 gestational weeks in the period 1999-2019, comparing patients with certain acute infection (seroconversion occurred in pregnancy, CAIP) with those with suspected acute infection (IgG positive with low/intermediate IgG avidity index, SAIP).

RESULTS

237 patients were enrolled, 187 (78.9%) with SAIP and 50 (21.1%) with CAIP. Specific IgM was detected in 47.5% and 76.7% (p-value 0.001), and the mean IgG avidity index was 22.7% and 7.1% (p-value < 0.001) in the SAIP and in the CAIP group, respectively. The mean delay from diagnosis to antibiotic initiation was 14.6 in SAIP and 11 days in CAIP group. Toxoplasma DNA was detected in the amniotic fluid in one case in a patient with CAIP. Excluding 24 newborns with not available data, prevalence of congenital infection was 0.47% [1/213 (95% CI 0.08%-2.61%)], 0% [0/178 (95% CI 0%-2.11%)] in SAIP and 2.8% [1/35 (95% CI 0.51%-14.53%)] in CAIP group.

CONCLUSIONS

Toxoplasmosis acquired in early pregnancy has a low risk of fetal infection. Actively discussing case-by-case amniocentesis indication with patients, especially when a recent toxoplasmosis is not properly confirmed, is desirable.

Non-Invasive Prenatal Test for β-Thalassemia and Sickle Cell Disease Using Probe Capture Enrichment and Next-Generation Sequencing of DNA in Maternal Plasma

BACKGROUND

Noninvasive prenatal testing (NIPT) of chromosomal aneuploidies based on next-generation sequencing (NGS) analysis of fetal DNA in maternal plasma is well established, but testing for autosomal recessive disorders remains challenging. NGS libraries prepared by probe capture facilitate the analysis of the short DNA fragments plasma. This system has been applied to the β-hemoglobinopathies to reduce the risk to the fetus.

METHOD

Our probe panel captures >4 kb of the HBB region and 435 single-nucleotide polymorphisms (SNPs) used to estimate fetal fraction. Contrived mixtures of DNA samples, plasma, and whole blood samples from 7 pregnant women with β-thalassemia or sickle cell anemia mutations and samples from the father, sibling, and baby or chorionic villus were analyzed. The fetal genotypes, including point mutations and deletions, were inferred by comparing the observed and expected plasma sequence read ratios, based on fetal fraction, at the mutation site and linked SNPs. Accuracy was increased by removing PCR duplicates and by in silico size selection of plasma sequence reads. A probability was assigned to each of the potential fetal genotypes using a statistical model for the experimental variation, and thresholds were established for assigning clinical status.

RESULTS

Using in silico size selection of plasma sequence files, the predicted clinical fetal genotype assignments were correct in 9 of 10 plasma libraries with maternal point mutations, with 1 inconclusive result. For 2 additional plasmas with deletions, the most probable fetal genotype was correct. The β-globin haplotype determined from linked SNPs, when available, was used to infer the fetal genotype at the mutation site.

CONCLUSION

This probe capture NGS assay demonstrates the potential of NIPT for β-hemoglobinopathies.

Chorionic villus-derived mesenchymal stem cell-mediated autophagy promotes the proliferation and invasiveness of trophoblasts under hypoxia by activating the JAK2/STAT3 signalling pathway

BACKGROUND

Trophoblast dysfunction during pregnancy is fundamentally involved in preeclampsia. Several studies have revealed that human chorionic villous mesenchymal stem cells (CV-MSCs) could regulate trophoblasts function.

RESULTS

To understand how human chorionic villous mesenchymal stem cells (CV-MSCs) regulate trophoblast function, we treated trophoblasts with CV-MSC supernatant under hypoxic conditions. Treatment markedly enhanced proliferation and invasion and augmented autophagy. Transcriptome and pathway analyses of trophoblasts before and after treatment revealed JAK2/STAT3 signalling as an upstream regulator. In addition, STAT3 mRNA and protein levels increased during CV-MSC treatment. Consistent with these findings, JAK2/STAT3 signalling inhibition reduced the autophagy, survival and invasion of trophoblasts, even in the presence of CV-MSCs, and blocking autophagy did not affect STAT3 activation in trophoblasts treated with CV-MSCs. Importantly, STAT3 overexpression increased autophagy levels in trophoblasts; thus, it positively regulated autophagy in hypoxic trophoblasts. Human placental explants also proved our findings by showing that STAT3 was activated and that LC3B-II levels were increased by CV-MSC treatment.

CONCLUSION

In summary, our data suggest that CV-MSC-dependent JAK2/STAT3 signalling activation is a prerequisite for autophagy upregulation in trophoblasts.

A two-year prospective study assessing the performance of fetal chromosomal microarray analysis and next-generation sequencing in high-risk pregnancies

Background

Introduction of cell‐free fetal DNA (cff‐DNA) testing in maternal blood opened possibilities to improve the performance of combined first‐trimester screening (cFTS) in terms of better detection of trisomies and lowering invasive testing rate. The use of new molecular methods, such as chromosomal microarray analysis (CMA) and next‐generation sequencing (NGS), has shown benefits in prenatal diagnosis of chromosomal and genetic diseases, which are not detectable with cff‐DNA screening, but require an invasive procedure.

Methods

The objective of this study was to evaluate prospectively during two years performance of CMA and NGS in high‐risk pregnancies. Initially, we investigated 14,566 singleton pregnancies with cFTS. A total of 334 high‐risk pregnancies were selected for CMA diagnostic performance evaluation and 28 cases of highly dysmorphic fetuses for NGS analysis. CMA study group was divided into two groups based on the indications for testing; group A patients with high‐risk for trisomies after cFTS, but normal ultrasound and group B patients who met criteria for CMA as a first‐tier diagnostic test.

Results

The diagnostic yield of CMA was overall 3.6% (1.6% in Group A and 6.0% in Group B). In NGS analysis group, we report diagnostic yield of 17.9%.

Conclusion

The use of CMA in high‐risk pregnancies is justified and provides relevant clinical information in 3.6% of the cases. NGS analysis in fetuses with multiple anomalies shows promising results, but more investigations are needed for a better understanding of practical applications of this molecular diagnosis method in prenatal settings.

The yield of chromosomal microarray in pregnancies with congenital cardiac defects and normal noninvasive prenatal screening

BACKGROUND

Evidence comparing the yield of chromosomal microarray analysis to noninvasive prenatal screening in pregnancies with congenital heart anomalies is currently limited.

OBJECTIVE

This study aimed to examine the residual risk of clinically significant chromosomal microarray analysis results in fetuses with congenital heart defects by its various subtypes following a normal noninvasive prenatal screening.

STUDY DESIGN

Using a population-based, countrywide computerized database, we retrieved the reports of all pregnancies undergoing chromosomal microarray analysis because of congenital heart defects through the years 2013-2019. We examined the risk of clinically significant (pathogenic and likely pathogenic) chromosomal microarray analysis results and compared it with the results of a local cohort of low-risk pregnancies. Of 5541 fetuses, 78 (1.4%) showed abnormal results. The residual risk of abnormal chromosomal microarray analysis results was calculated using several options-trisomies 21, 18, and 13; sex chromosome aneuploidies; 22q11.2 deletion, and deletions and duplications of at least 10 MB in size (genome-wide noninvasive prenatal screening)-following the exclusion of theoretically detectable noninvasive prenatal screening anomalies.

RESULTS

Of the 1728 fetuses with congenital heart defects, 93 (5.4%) showed clinically significant chromosomal microarray analysis results (relative risk, 2.7; 95% confidence interval, 2.3-3.1). The result of pregnancies with fetuses with congenital heart defects was compared with the results of the control population. Unique variants were found in 15 pregnancies (16.1%). The detection rate of noninvasive prenatal screening in isolated congenital heart defects varied from 1.0% (aimed at 3 common trisomies) to 2.2% (aimed at 5 common aneuploidies and 22q11.2 deletion) using noninvasive prenatal screening. In nonisolated congenital heart defects, the noninvasive prenatal screening detection rates ranged from 7.8% (aimed at common autosomal trisomies) to 9.2% using genome-wide noninvasive prenatal screening. The residual risk of clinically significant chromosomal microarray analysis results following normal noninvasive prenatal screening ranged from 2.0% to 2.8% in isolated congenital heart defects and 4.5% to 5.9% in nonisolated cases and was significantly higher than those of the control cohort in all noninvasive prenatal screening options. In addition, the residual risk following noninvasive prenatal screening aimed at chromosomes 13, 18, 21, X, and Y was significantly higher than those of the control cohort for most specific congenital heart defect subtypes, except for ventricular septal defects and aberrant right subclavian artery.

CONCLUSION

The residual risk of clinically significant chromosomal microarray analysis results in pregnancies with fetuses with congenital heart defects following normal noninvasive prenatal screening was higher than those in pregnancies with normal ultrasound in most isolated and nonisolated congenital heart defect subtypes. This information should be taken into account by obstetricians and genetic counselors when considering the option of diagnostic testing.

Intra-amniotic levothyroxine infusions in a case of fetal goiter due to novel Thyroglobulin gene variants

Indications and administration of intra-amniotic infusions of L-thyroxine in the context of non-immune fetal hypothyroidism with goiter lack of standardization. Systematic follow-up of clinical features related to thyroid hormonal homeostasis may be useful to evaluate their efficiency and develop standardized management guidelines.

Trends of fetal chromosome analysis by amniocentesis before and after beginning of noninvasive prenatal testing: A single-center experience in Japan

AIM

This study is to investigate the role of amniocentesis for prenatal diagnosis before and after the beginning of noninvasive prenatal testing (NIPT) in Japan.

METHODS

We performed a retrospective analysis of genetic amniocentesis at mid-trimester (15-20 gestational weeks) for fetal karyotype analysis at Nagoya City University between April 2006 and March 2020. The indications, test results, and the detection rate of fetal abnormal karyotype were compared before (phase 1, P1) and after (phase 2, P2) beginning of NIPT at April 2013.

RESULTS

A total of 2458 (P1: 1132, P2: 1326) amniocentesis were enrolled in this study. The most frequent indication was advanced maternal age in both phases (P1: 78.2% %, P2: 81.1%). In P2, 110 patients (8.3%) received amniocentesis after positive or nonreportable NIPT results. Other indications were fetal abnormal findings by ultrasounds (P1: 15.4%, P2: 17.7%), abnormal maternal serum screening results (P1: 8.0%, P2: 10%), previous child with fetal chromosome aberration (P1: 6.5%, P2: 3.5%), and translocation of either partner (P1:1.5%, P2: 2.1%). The detection rate for fetal chromosomal aberrations including all indications was significantly increased in P2 (15.9%, 95% CI 14.0-18.0) as compared to P1 (9.0%, 7.4-10.8). However, if the indication was only advanced maternal age, the positive detection rate kept low in both phases (P1: 5.2%, 3.7-7.1, P2: 4.2%, 2.9-5.9).

CONCLUSION

Since the initiation of NIPT, the detection rate of fetal chromosomal abnormalities was higher in this study, suggesting that amniocentesis cannot be strongly recommended for advanced maternal age alone.

From late fatherhood to prenatal screening of monogenic disorders: evidence and ethical concerns

BACKGROUND

With the help of ART, an advanced parental age is not considered to be a serious obstacle for reproduction anymore. However, significant health risks for future offspring hide behind the success of reproductive medicine for the treatment of reduced fertility associated with late parenthood. Although an advanced maternal age is a well-known risk factor for poor reproductive outcomes, understanding the impact of an advanced paternal age on offspring is yet to be elucidated. De novo monogenic disorders (MDs) are highly associated with late fatherhood. MDs are one of the major sources of paediatric morbidity and mortality, causing significant socioeconomic and psychological burdens to society. Although individually rare, the combined prevalence of these disorders is as high as that of chromosomal aneuploidies, indicating the increasing need for prenatal screening. With the help of advanced reproductive technologies, families with late paternity have the option of non-invasive prenatal testing (NIPT) for multiple MDs (MD-NIPT), which has a sensitivity and specificity of almost 100%.

OBJECTIVE AND RATIONALE

The main aims of the current review were to examine the effect of late paternity on the origin and nature of MDs, to highlight the role of NIPT for the detection of a variety of paternal age-associated MDs, to describe clinical experiences and to reflect on the ethical concerns surrounding the topic of late paternity and MD-NIPT.

SEARCH METHODS

An extensive search of peer-reviewed publications (1980-2021) in English from the PubMed and Google Scholar databases was based on key words in different combinations: late paternity, paternal age, spermatogenesis, selfish spermatogonial selection, paternal age effect, de novo mutations (DNMs), MDs, NIPT, ethics of late fatherhood, prenatal testing and paternal rights.

OUTCOMES

An advanced paternal age provokes the accumulation of DNMs, which arise in continuously dividing germline cells. A subset of DNMs, owing to their effect on the rat sarcoma virus protein-mitogen-activated protein kinase signalling pathway, becomes beneficial for spermatogonia, causing selfish spermatogonial selection and outgrowth, and in some rare cases may lead to spermatocytic seminoma later in life. In the offspring, these selfish DNMs cause paternal age effect (PAE) disorders with a severe and even life-threatening phenotype. The increasing tendency for late paternity and the subsequent high risk of PAE disorders indicate an increased need for a safe and reliable detection procedure, such as MD-NIPT. The MD-NIPT approach has the capacity to provide safe screening for pregnancies at risk of PAE disorders and MDs, which constitute up to 20% of all pregnancies. The primary risks include pregnancies with a paternal age over 40 years, a previous history of an affected pregnancy/child, and/or congenital anomalies detected by routine ultrasonography. The implementation of NIPT-based screening would support the early diagnosis and management needed in cases of affected pregnancy. However, the benefits of MD-NIPT need to be balanced with the ethical challenges associated with the introduction of such an approach into routine clinical practice, namely concerns regarding reproductive autonomy, informed consent, potential disability discrimination, paternal rights and PAE-associated issues, equity and justice in accessing services, and counselling.

WIDER IMPLICATIONS

Considering the increasing parental age and risks of MDs, combined NIPT for chromosomal aneuploidies and microdeletion syndromes as well as tests for MDs might become a part of routine pregnancy management in the near future. Moreover, the ethical challenges associated with the introduction of MD-NIPT into routine clinical practice need to be carefully evaluated. Furthermore, more focus and attention should be directed towards the ethics of late paternity, paternal rights and paternal genetic guilt associated with pregnancies affected with PAE MDs.

Comprehensive Evaluation of Non-invasive Prenatal Screening to Detect Fetal Copy Number Variations

Objective

To evaluate the effectiveness of non-invasive prenatal screening (NIPS) in prenatal screening of fetal pathogenic copy number variants (CNVs).

Materials and Methods

We evaluated the prenatal screening capacity using traditional and retrospective approaches. For the traditional method, we evaluated 24,613 pregnant women who underwent NIPS; cases which fetal CNVs were suggested underwent prenatal diagnosis with chromosomal microarray analysis (CMA). For the retrospective method, we retrospectively evaluated 47 cases with fetal pathogenic CNVs by NIPS. A systematic literature search was performed to compare the evaluation efficiency.

Results

Among the 24,613 pregnant women who received NIPS, 124 (0.50%) were suspected to have fetal CNVs. Of these, 66 women underwent prenatal diagnosis with CMA and 13 had true-positive results. The positive predictive value (PPV) of NIPS for fetal CNVs was 19.7%. Among 1,161 women who did not receive NIPS and underwent prenatal diagnosis by CMA, 47 were confirmed to have fetal pathogenic CNVs. Retesting with NIPS indicated that 24 of these 47 cases could also be detected by NIPS, representing a detection rate (DR) of 51.1%. In total, 10 publications, namely, six retrospective studies and four prospective studies, met our criteria and were selected for a detailed full-text review. The reported DRs were 61.10–97.70% and the PPVs were 36.11–80.56%. The sizes of CNVs were closely related to the accuracy of NIPS detection. The DR was 41.9% (13/31) in fetuses with CNVs ≤ 3 Mb, but was 55.0% (11/20) in fetuses with CNVs > 3 Mb. Finally, to intuitively show the CNVs accurately detected by NIPS, we mapped all CNVs to chromosomes according to their location, size, and characteristics. NIPS detected fetal CNVs in 2q13 and 4q35.

Conclusion

The DR and PPV of NIPS for fetal CNVs were approximately 51.1% and 19.7%, respectively. Follow-up molecular prenatal diagnosis is recommended in cases where NIPS suggests fetal CNVs.

In utero adenine base editing corrects multi-organ pathology in a lethal lysosomal storage disease

In utero base editing has the potential to correct disease-causing mutations before the onset of pathology. Mucopolysaccharidosis type I (MPS-IH, Hurler syndrome) is a lysosomal storage disease (LSD) affecting multiple organs, often leading to early postnatal cardiopulmonary demise. We assessed in utero adeno-associated virus serotype 9 (AAV9) delivery of an adenine base editor (ABE) targeting the Idua G→A (W392X) mutation in the MPS-IH mouse, corresponding to the common IDUA G→A (W402X) mutation in MPS-IH patients. Here we show efficient long-term W392X correction in hepatocytes and cardiomyocytes and low-level editing in the brain. In utero editing was associated with improved survival and amelioration of metabolic, musculoskeletal, and cardiac disease. This proof-of-concept study demonstrates the possibility of efficiently performing therapeutic base editing in multiple organs before birth via a clinically relevant delivery mechanism, highlighting the potential of this approach for MPS-IH and other genetic diseases.

Study for risks of amniocentesis in anterior placenta compared to placenta of other locations

OBJECTIVE

This study aimed to compare the risks of amniocentesis between anteriorly located placentas and placentas in other locations and assess the factors that cause procedure-related complications.

MATERIALS AND METHODS

We prospectively studied women with singleton pregnancies who underwent amniocentesis between 2014 and 2020. The amniocentesis puncture sites were determined using ultrasonography. Women were classified into two groups according to their placental location. Medical records were retrospectively reviewed and characteristics and complications were compared between the groups of patients with different placental locations.

RESULTS

During the study period, 629 women underwent amniocentesis. Three cases (0.5%) of premature rupture of membranes and one case (0.3%) of fetal loss within four weeks of amniocentesis were found. Puncture failure was observed in 14 cases (2.2%). Puncture failure included procedures with failure to obtain an adequate sample and procedures requiring more than three needle insertions. There was no significant difference in the frequency of puncture failure between the two groups. Logistic regression analysis revealed that uterine myoma (odds ratio [OR] 11.92; 95% CI, 3.04-45.17) and tenting membrane (OR 33.57; 95% CI, 6.45-178.41) were associated with puncture failure.

CONCLUSION

Anteriorly located placenta is not a risk factor for amniocentesis-related adverse outcomes. Instead, puncture failure frequently occurs in case of uterine myoma and tenting membrane. If puncture failure occurs, or if the puncture is difficult to perform, then the procedure should be considered technically difficult and postponed until it can be more easily performed.

Amniotic fluid interleukin 6 and interleukin 8 are superior predictors of fetal lung injury compared with maternal or fetal plasma cytokines or placental histopathology in a nonhuman primate model

BACKGROUND

Intra-amniotic infection or inflammation is common in early preterm birth and associated with substantial neonatal lung morbidity owing to fetal exposure to proinflammatory cytokines and infectious organisms. Amniotic fluid interleukin 8, a proinflammatory cytokine, was previously correlated with the development of neonatal bronchopulmonary dysplasia, but whether amniotic fluid cytokines or placental pathology more accurately predicts neonatal lung pathology and morbidity is unknown. We have used a pregnant nonhuman primate model of group B Streptococcus infection to study the pathogenesis of intra-amniotic infection, bacterial invasion of the amniotic cavity and fetus, and microbial-host interactions. In this nonhuman primate model, we have studied the pathogenesis of group B Streptococcus strains with differing potential for virulence, which has resulted in a spectrum of intra-amniotic infection and fetal lung injury that affords the opportunity to study the inflammatory predictors of fetal lung pathology and injury.

OBJECTIVE

This study aimed to determine whether fetal lung injury is best predicted by placental histopathology or the cytokine response in amniotic fluid or maternal plasma.

STUDY DESIGN

Chronically catheterized pregnant monkeys (Macaca nemestrina, pigtail macaque) at 116 to 125 days gestation (term at 172 days) received a choriodecidual inoculation of saline (n=5), weakly hemolytic group B Streptococcus strain (n=5, low virulence), or hyperhemolytic group B Streptococcus strain (n=5, high virulence). Adverse pregnancy outcomes were defined as either preterm labor, microbial invasion of the amniotic cavity, or development of the fetal inflammatory response syndrome. Amniotic fluid and maternal and fetal plasma samples were collected after inoculation, and proinflammatory cytokines (tumor necrosis factor alpha, interleukin beta, interleukin 6, interleukin 8) were measured by a multiplex assay. Cesarean delivery was performed at the time of preterm labor or within 1 week of inoculation. Fetal necropsy was performed at the time of delivery. Placental pathology was scored in a blinded fashion by a pediatric pathologist, and fetal lung injury was determined by a semiquantitative score from histopathology evaluating inflammatory infiltrate, necrosis, tissue thickening, or collapse scored by a veterinary pathologist.

RESULTS

The principal findings in our study are as follows: (1) adverse pregnancy outcomes occurred more frequently in animals receiving hyperhemolytic group B Streptococcus (80% with preterm labor, 80% with fetal inflammatory response syndrome) than in animals receiving weakly hemolytic group B Streptococcus (40% with preterm labor, 20% with fetal inflammatory response syndrome) and in controls (0% preterm labor, 0% fetal inflammatory response syndrome); (2) despite differences in the rate of adverse pregnancy outcomes and fetal inflammatory response syndrome, fetal lung injury scores were similar between animals receiving the weakly hemolytic group B Streptococcus strains and animals receiving the hyperhemolytic group B Streptococcus strains; (3) fetal lung injury score was significantly correlated with peak amniotic fluid cytokines interleukin 6 and interleukin 8 but not tumor necrosis factor alpha or interleukin 1 beta; and (4) fetal lung scores were poorly correlated with maternal and fetal plasma cytokine levels and placental pathology.

CONCLUSION

Amniotic fluid interleukin 6 and interleukin 8 levels were superior predictors of fetal lung injury than placental histopathology or maternal plasma cytokines. This evidence supports a role for amniocentesis in the prediction of neonatal lung morbidity owing to intra-amniotic infection, which cannot be provided by cytokine analysis of maternal plasma or placental histopathology.

Is cervical swab an efficient method for developing a new noninvasive prenatal diagnostic test for numerical and structural chromosome anomalies?

Background/aim

Prenatal diagnosis is vital to obtain healthy generation for risky pregnancies. There have been several approaches, some of which are routinely applied in clinics to evaluate the possible prenatal deficiencies and/or diseases. In the present study, we aimed to isolate the fetal cells from endocervical samples and try to identify possible anomalies which were proved by Amniocentesis (AS) and chorionic villus sampling (CVS) methods.

Materials and methods

Endoservical specimens were collected from 100 pregnant women. Cells were separated in parallel by fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) using human leukocyte antigen (HLA) G233 and placental alkaline phosphatase (PLAP) antibodies. CMA (comprehensive meta-analysis) were carried out and male fetuses were confirmed with Sex determining region Y (SRY) amplification.

Results

The percent of HLA G233 and placental and placental alkaline phosphatase (PLAP) positive cells were 4.55% and 84.59%, respectively. The percent of cells positive for both markers was 14.75%. CMA analyses were not informative. (SRY) was amplified in 67% of the samples.

Conclusion

However, the success rate of the both cell sorting and scanning of DNA anomalies by aCGH and/or RT-PCR was limited, preventing the applicability of this proposal in the clinics. Still, the success of the proposed method depends on the development of the novel fetal cell-specific antibodies and the improvements in the sorting systems.

Screening of Candidate Pathogenic Genes for Spontaneous Abortion using Whole Exome Sequencing

BACKGROUND

Spontaneous abortion is a common disease in obstetrics and reproduction.

OBJECTIVE

This study aimed to screen candidate pathogenic genes for spontaneous abortion using whole-exome sequencing.

METHODS

Genomic DNA was extracted from abortion tissues of spontaneous abortion patients and sequenced using the Illumina HiSeq2500 high-throughput sequencing platform. Whole exome sequencing was performed to select harmful mutations, including SNP and insertion and deletion sites, associated with spontaneous abortion. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses and gene fusion analyses were performed. MUC3A and PDE4DIP were two novel mutation genes that were screened and verified by PCR in abortion tissues of patients.

RESULTS

A total of 83,633 SNPs and 13,635 Indel mutations were detected, of which 29172 SNPs and 3093 Indels were screened as harmful mutations. The 7 GO-BP, 4 GO-CC, 9 GO-MF progress, and 3 KEGG pathways were enriched in GO and KEGG pathway analyses. A total of 746 gene fusion mutations were obtained, involving 492 genes. MUC3A and PDE4DIP were used for PCR verification because of their high number of mutation sites in all samples.

CONCLUSION

There are extensive SNPs and Indel mutations in the genome of spontaneous abortion tissues, and the effect of these gene mutations on spontaneous abortion needs further experimental verification.

Metabolomics in Prenatal Medicine: A Review

Pregnancy is a complicated and insidious state with various aspects to consider, including the well-being of the mother and child. Developing better non-invasive tests that cover a broader range of disorders with lower false-positive rates is a fundamental necessity in the prenatal medicine field, and, in this sense, the application of metabolomics could be extremely useful. Metabolomics measures and analyses the products of cellular biochemistry. As a biomarker discovery tool, the integrated holistic approach of metabolomics can yield new diagnostic or therapeutic approaches. In this review, we identify and summarize prenatal metabolomics studies and identify themes and controversies. We conducted a comprehensive search of PubMed and Google Scholar for all publications through January 2020 using combinations of the following keywords: nuclear magnetic resonance, mass spectrometry, metabolic profiling, prenatal diagnosis, pregnancy, chromosomal or aneuploidy, pre-eclampsia, fetal growth restriction, pre-term labor, and congenital defect. Metabolite detection with high throughput systems aided by advanced bioinformatics and network analysis allowed for the identification of new potential prenatal biomarkers and therapeutic targets. We took into consideration the scientific papers issued between the years 2000-2020, thus observing that the larger number of them were mainly published in the last 10 years. Initial small metabolomics studies in perinatology suggest that previously unidentified biochemical pathways and predictive biomarkers may be clinically useful. Although the scientific community is considering metabolomics with increasing attention for the study of prenatal medicine as well, more in-depth studies would be useful in order to advance toward the clinic world as the obtained results appear to be still preliminary. Employing metabolomics approaches to understand fetal and perinatal pathophysiology requires further research with larger sample sizes and rigorous testing of pilot studies using various omics and traditional hypothesis-driven experimental approaches.

Difference in Procedure-Related Risk of Miscarriage between Early and Mid-Trimester Amniocentesis: A Retrospective Cohort Study

Early amniocentesis (EA)—before 15 gestational weeks—is not recommended because of a high rate of miscarriages. Most studies performed amniocentesis at very early stages of pregnancy (11–13 weeks of gestational age). However, amniocentesis performed at 14 gestational weeks could be an important alternative to mid-trimester amniocentesis (MA) because it shortens the time period between the screening (non-invasive prenatal test (NIPT)) and the diagnostic test (amniocentesis). This study aimed to compare the procedure-related risk of miscarriage between MA (15 + 0 to 17 + 6 weeks of gestational age) and EA (14 + 0–6 weeks of gestational age). This is a multicentric, retrospective cohort study from 1 January 2007 to 21 November 2018, comparing the MA to the EA cohort. Procedure-related fetal loss is defined as spontaneous abortion occurring within 4 weeks of the procedure. Multiple gestations, amniocenteses performed after 17 or before 14 weeks, indications other than prenatal genetic diagnoses and procedures performed by less experienced gynaecologists were excluded. Complete outcome data were available for 1107 out of 1515 women (73.1%): 809 (69.9%) in the MA and 298 (83.2%) in the EA cohort. No significant difference was found (EA 0.82% vs. MA 0.36%; p = 0.646). The difference was 0.46% (odds ratio = 0.673; 95% confidence interval = 0.123–3.699). This study found no significant difference in the procedure-related risk of miscarriage when EA was compared to MA. EA might be considered a safe alternative, though further research is necessary.

Performance of a Paired-End Sequencing-Based Noninvasive Prenatal Screening Test in the Detection of Genome-Wide Fetal Chromosomal Anomalies

BACKGROUND

Noninvasive prenatal tests (NIPTs) detect fetal chromosomal anomalies with high clinical sensitivity and specificity. We examined the performance of a paired-end sequencing-based NIPT in the detection of genome-wide fetal chromosomal anomalies including common trisomies, sex chromosomal aneuploidies (SCA), rare autosomal aneuploidies (RAAs), and partial deletions/duplications ≥7 Mb.

METHODS

Frozen plasma samples from pregnant women were tested using the VeriSeq NIPT Solution v2 assay. All samples were previously tested with a laboratory-developed NIPT and had known clinical outcomes. Individuals performing the sequencing were blinded to clinical outcome data. Clinical sensitivity and specificity were determined for basic (chromosomes 21, 18, 13, X, and Y) and genome-wide screening modes.

RESULTS

Of 2335 samples that underwent genome-wide analysis, 28 did not meet QC requirements, resulting in a first-pass assay failure rate of 1.2%. Basic screening analysis, excluding known mosaics, correctly classified 130/130 trisomy 21 samples (sensitivity >99.9%, 95% confidence interval [CI] 97.1%-100%), 41/41 trisomy 18 samples (sensitivity >99.9%, 95% CI 91.4%-100%), and 26/26 trisomy 13 samples (sensitivity >99.9%, 95% CI 87.1%-100%) with 6 false-positive results; specificities ≥99.90% were reported for all 3 trisomies. Concordance for SCAs ranged from 90.5%-100%. Genome-wide screening analysis including known mosaics correctly classified 27/28 RAAs and 20/27 partial deletions/duplications with a specificity of 99.80% for both anomalies, and an overall genome-wide specificity for all anomalies of 99.34%.

CONCLUSIONS

The VeriSeq NIPT Solution v2 assay enables accurate identification of fetal aneuploidy, allowing detection of genome-wide fetal chromosomal anomalies with high clinical sensitivities and specificities and a low assay failure rate.Clinical Trial Notification [CTN] identification number [ID]: CT-2018-CTN-01585-1 v1, Protocol: NIPT T05 002.

Prenatal Screening of Trisomy 21: Could Oxidative Stress Markers Play a Role?

Despite significant progress in trisomy 21 (T21) diagnostic tools, amniocentesis is still used for the confirmation of an abnormal fetal karyotype. Invasive tests carry the potential risk of miscarriage; thus, screening biomarkers are commonly used before undergoing invasive procedures. In our study, we investigated the possible application of oxidative stress markers in the prenatal screening of trisomy 21. The DNA/RNA oxidative stress damage products (OSDPs), advanced glycation end (AGE) products, ischemia-modified albumin (IMA), alfa-1-antitrypsin (A1AT), asprosin, and vitamin D concentrations were measured in both maternal plasma and amniotic fluid in trisomy 21 (T21) and euploid pregnancies. The obtained results indicated increased levels of DNA/RNA OSDPs and asprosin with simultaneous decreased levels of vitamin D and A1AT in the study group. The diagnostic utility of the plasma measurement based on the area under the received operative characteristic (ROC) curve (AUC) calculation of asprosin (AUC = 0.965), IMA (AUC = 0.880), AGE (AUC = 0.846) and DNA/RNA OSDPs (AUC = 0.506) in T21 screening was demonstrated. The obtained results indicate a potential role for the application of oxidative stress markers in the prenatal screening of T21 with the highest screening utility of plasma asprosin.

Outcome of antenatal invasive diagnostic tests in a fetal medicine unit with low case load in North Wales, United Kingdom

The aim of this retrospective cohort study was to review rate of miscarriage following antenatal invasive diagnostic procedures from a unit where relatively low annual numbers of procedures are undertaken. Data were analysed for 201 chorionic villous samplings (CVSs) performed between January 2007 and June 2019 and 511 amniocenteses performed between January 2008 and June 2019, in singleton pregnancies. The miscarriage rates after CVS was 0% at 48 hours, 0.6% at 2 weeks and 2.5% up to 24 weeks of gestation. All four miscarriages following CVS had significant inherent high-risk features, therefore, it would be inappropriate to attribute these losses solely to the procedure itself. None of the women who had an amniocentesis had a miscarriage during the study period. We did not find a causal association between number of invasive procedures performed by an operator and miscarriage rate in our setting even with low annual numbers of invasive procedures.Impact StatementWhat is already known on this subject? Royal College of Obstetricians and Gynaecologists (RCOG) of UK recommends a minimum of at least 30 CVSs or amniocenteses procedures per year for a practitioner in order to maintain skills. A centre performing more fetal invasive procedures has lower miscarriage rates due to more experience of practitioners.What the results of this study add? This study is the first long-term audit data from a smaller fetal medicine unit with relatively low annual case load, suggesting that miscarriage risk may actually be lower than the current understanding. No additional risk of miscarriage or pregnancy loss following fetal invasive procedures even with relatively low annual numbers than that recommended by the RCOG.What the implications are of these findings for clinical practice and/or further research? The findings of this study are important in the era of non-invasive prenatal testing which will see the overall number of fetal invasive procedures decline with time. Competence in safely undertaking antenatal invasive procedure can possibly be maintained with lower annual procedure numbers. Units undertaking low number of antenatal invasive procedure must continuously audit their practice to ensure satisfactory standards and outcomes. More research is needed from smaller units to corroborate or refute the findings of this study.

Follow-up in Patients With Non-invasive Prenatal Screening Failures: A Reflection on the Choice of Further Prenatal Diagnosis

Background

Our aim was to provide a theoretical basis for clinicians to conduct genetic counseling and choose further prenatal diagnosis methods for pregnant women who failed non-invasive prenatal screening (NIPS).

Methods

A retrospective analysis was performed on pregnant women who had failed NIPS tests.

Results

Among the 123,291 samples, 394 pregnant women did not obtain valid results due to test failures. A total of 378 pregnant women were available for follow-up, while 16 patients were lost to follow-up. Of these 378, 135 pregnant women chose further prenatal diagnosis through amniocentesis, and one case of dysplasia was recalled for postpartum chromosome testing. The incidence rate of congenital chromosomal abnormalities in those who failed the NIPS was 3.97% (15/378), which was higher than that of the chromosomal abnormalities in the common population (1.8%). Among the pregnant women who received prenatal diagnosis, the positive rates of chromosomal abnormalities in the chromosomal microarray analysis/copy number variation sequencing (CMA/CNV-seq) group and in the karyotyping group were 15.28 and 4.76%, respectively.

Conclusion

Prenatal diagnosis should be strongly recommended in posttest genetic counseling for pregnant women with NIPS failures. Further, high-resolution detection methods should be recommended for additional prenatal diagnoses.

Current Overview of Osteogenesis Imperfecta

Osteogenesis imperfecta (OI), or brittle bone disease, is a heterogeneous disorder characterised by bone fragility, multiple fractures, bone deformity, and short stature. OI is a heterogeneous disorder primarily caused by mutations in the genes involved in the production of type 1 collagen. Severe OI is perinatally lethal, while mild OI can sometimes not be recognised until adulthood. Severe or lethal OI can usually be diagnosed using antenatal ultrasound and confirmed by various imaging modalities and genetic testing. The combination of imaging parameters obtained by ultrasound, computed tomography (CT), and magnetic resource imaging (MRI) can not only detect OI accurately but also predict lethality before birth. Moreover, genetic testing, either noninvasive or invasive, can further confirm the diagnosis prenatally. Early and precise diagnoses provide parents with more time to decide on reproductive options. The currently available postnatal treatments for OI are not curative, and individuals with severe OI suffer multiple fractures and bone deformities throughout their lives. In utero mesenchymal stem cell transplantation has been drawing attention as a promising therapy for severe OI, and a clinical trial to assess the safety and efficacy of cell therapy is currently ongoing. In the future, early diagnosis followed by in utero stem cell transplantation should be adopted as a new therapeutic option for severe OI.

Universal chromosomal microarray analysis reveals high proportion of copy-number variants in low-risk pregnancies

OBJECTIVES

To evaluate the yield and utility of the routine use of chromosomal microarray analysis (CMA) for prenatal genetic diagnosis in a large cohort of pregnancies with normal ultrasound (US) at the time of genetic testing, compared with pregnancies with abnormal US findings.

METHODS

We reviewed all prenatal CMA results in our center between November 2013 and December 2018. The prevalence of different CMA results in pregnancies with normal US at the time of genetic testing ('low-risk pregnancies'), was compared with that in pregnancies with abnormal US findings ('high-risk pregnancies'). Medical records were searched in order to evaluate subsequent US follow-up and the outcome of pregnancies with a clinically relevant copy-number variant (CNV), i.e. a pathogenic or likely pathogenic CNV or a susceptibility locus for disease with > 10% penetrance, related to early-onset disease in the low-risk group.

RESULTS

In a cohort of 6431 low-risk pregnancies that underwent CMA, the prevalence of a clinically significant CNV related to early-onset disease was 1.1% (72/6431), which was significantly lower than the prevalence in high-risk pregnancies (4.9% (65/1326)). Of the low-risk pregnancies, 0.4% (27/6431) had a pathogenic or likely pathogenic CNV, and another 0.7% (45/6431) had a susceptibility locus with more than 10% penetrance. Follow-up of the low-risk pregnancies with a clinically significant early-onset CNV revealed that 31.9% (23/72) were terminated, while outcome data were missing in 26.4% (19/72). In 16.7% (12/72) of low-risk pregnancies, an US abnormality was discovered later on in gestation, after genetic testing had been performed.

CONCLUSION

Although the background risk of identifying a clinically significant early-onset abnormal CMA result in pregnancies with a low a-priori risk is lower than that observed in high-risk pregnancies, the risk is substantial and should be conveyed to all pregnant women. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal screening for Down syndrome: popularity, perceptions and factors associated with acceptance or refusal of testing

BACKGROUND

Prenatal screening tests for aneuploidies have become increasingly used in maternal and fetal medicine. Given that all pregnancies associate a potential risk of Down syndrome, adequate knowledge of the tests, and their characteristics as well as facilitating decision-making autonomy are fundamental rights that must be respected.

OBJECTIVES

Identification of the popularity of the tests, their perception and the factors associated with the acceptance or refusal to perform them.

METHODS

A cross-sectional study was carried out in the South-East region of Romania, between April and September 2016. The data were collected from 275 postpartum women. The instrument used was a self-administered questionnaire and the data obtained were processed using the IBM SPSS 20.0 statistical software (IBM Corp., Armonk, NY, USA). The normality of the distribution was analyzed with Chi-square, Kolmogorov-Smirnov and Shapiro-Wilk tests. Factorial Analysis was carried out for the Principal Components of the scales for the reasons for performing and not performing.

RESULTS

The 2nd Trimester Morphology had the popularity as well as the highest rate of accomplishment (98.2% respectively 67.6%) among the investigated women. It is also the preferred recommendation of the specialists (81.1%). The least popular test was the TPNI, only 13.1% of the participants heard about it, as it was recommended in only 2% of the situations. Most of the participants perceived the screening tests as essential and useful, but 43.3% considered that they become mandatory if the doctor recommends them. The acceptance of the child with DS and the misperception of the risk were the main factors associated with the refusal of the test and the compliance with the recommendation of the specialist (system confidence), and social influence (non-acceptance of the Down syndrome by the society) were the main factors associated with the acceptance.

CONCLUSIONS

The number of women who made the decision to accept the test was greater than the ones who refused. The amendment is that acceptance was based on the custom of socio-economic-medical compliance and responsibility. For many women, the motivation of acceptance meant alignment with the normality directed by the society and the system. Even the popularity of the tests carries the imprint of the beliefs and values of the system and the specialists involved. For an adequate perception and an autonomous and informed choice of women, the screening program must include adequate information and communication services by involving specialists responsible for multidisciplinary competencies. The percentage of completion and the type of test performed almost perfectly align with the recommendations received.

Benefit versus risk of chromosomal microarray analysis performed in pregnancies with normal and positive prenatal screening results: A retrospective study

Background

Most studies on chromosomal microarray analysis (CMA) and amniocentesis risks have not evaluated pregnancies with low risk for genetic diseases; therefore, the efficacy and safety of CMA and amniocentesis in this population are unclear. This study aimed to examine the benefits and risks of prenatal genetic diagnostic tests in pregnancies having low risk for chromosomal diseases.

Methods and findings

In this retrospective study, we used clinical data from a large database of 30,830 singleton pregnancies at gestational age 16–23 weeks who underwent amniocentesis for karyotyping with or without CMA. We collected socio-demographic, medical and obstetric information, along with prenatal screening, CMA and karyotyping results. Fetal loss events were also analysed. CMA was performed in 5,837 pregnancies with normal karyotype (CMA cohort). In this cohort, 4,174 women had normal prenatal screening results and the risk for identifying genetic abnormalities with >10% risk for intellectual disability by CMA was 1:102, with no significant difference between maternal age groups. The overall post-amniocentesis fetal loss rate was 1:1,401 for the entire cohort (n = 30,830) and 1:1,945 for the CMA cohort (n = 5,837). The main limitation of this study is the relatively short follow-up of 3 weeks, which may not have been sufficient for detecting all fetal loss events.

Conclusion

The low risk for post-amniocentesis fetal loss, compared to the rate of severe genetic abnormalities detected by CMA, suggests that even pregnant women with normal prenatal screening results should consider amniocentesis with CMA.

Clinical management of mosaic results from preimplantation genetic testing for aneuploidy (PGT-A) of blastocysts: a committee opinion

Since the advent of preimplantation genetic testing for aneuploidy (PGT-A) in the 1990s, substantial changes in test methodology and technology now allow the detection and reporting of intermediate chromosome copy number (commonly referred to as mosaicism) for aneuploidy in a trophectoderm biopsy sample. Clinicians are grappling with how to interpret such findings and how to counsel patients about embryo transfer decision-making. This document reviews the available literature and outlines the various issues surrounding the reporting of intermediate copy number and consideration of storage or transfer of blastocysts with intermediate copy number results. This document does not endorse, nor does it suggest that PGT-A is appropriate for all cases of in vitro fertilization.

Is it time for prenatal chromosomal-microarray analysis to all women? A review of the diagnostic yield in structurally normal fetuses

PURPOSE OF REVIEW

Chromosomal-microarray analysis (CMA) is the first-tier test in pregnancies with structural malformations. Accumulating data show that pathogenic copy number variants (CNVs) can also be identified in structurally normal fetuses. We set out to summarize the published data on the diagnostic yield of CMA in structurally normal fetuses.

RECENT FINDINGS

Six studies summarize a total of 29,612 prenatal CMAs performed in structurally normal fetuses. The incidence of highly penetrant pathogenic/likely pathogenic CNVs is 0.4-2.5%. Variability was demonstrated in the timing of CMA testing and type of CNVs classified as pathogenic. The incidence of variants of uncertain significance is 0.4-5.4%. The prevalence of susceptibility loci is 0.3-0.7% when specified, and the incidence of CNVs associated with late onset disease is 0.1%.

SUMMARY

With a frequency of abnormal CNVs of 1:40 to 1:250 in structurally normal fetuses, it is recommended that all pregnant women be informed of the possibility to have CMA performed, even in the absence of malformations. Information should also be provided about uncertain and secondary findings.

Cesarean section and pregnancy outcomes of preterm premature rupture of membranes under different fertility policies in China

BACKGROUND

The aim of the present study was to compare the outcomes of pregnancies complicated by preterm premature rupture of membranes (PPROM) in China.

METHODS

The present study was a single-center retrospective study of women admitted to Beijing Obstetrics and Gynecology Hospital in 2012, 2014, and 2017. Deliveries at <24 and >37 weeks, fatal deformities, stillbirths, and multiple pregnancies were excluded. Pregnancies were divided into 24-27⁺⁶, 28-33⁺⁶, and 34-36⁺⁶ weeks according to weeks of gestation in each year. In total, 1,178 pregnancies complicated by PPROM were analyzed in terms of incidence rate, risk factors, delivery mode, and neonatal outcomes.

RESULTS

The rate of PPROM was 3.11% in 2012, 2.35% in 2014, and 2.4% in 2017; the difference was significant (P<0.001). Age [odds ratio (OR): 1.046, P<0.001], intrauterine infection (OR: 2.087, P=0.007), and vaginitis (OR: 1.812, P=0.039) were risk factors for PPROM. In all 3 years, patients with PPROM tended to choose vaginal delivery rather than cesarean section (CS) delivery (68.9% in 2012, P<0.001; 76.5% in 2014, P<0.001; 69.3% in 2017, P<0.001), and the rate of vaginal deliveries in 2014 was higher than that in 2012 and 2017 (P=0.027). Indications for PPROM at 34-36⁺⁶ weeks varied significantly among the 3 years (P<0.001). No significant difference was found in body weight, body length, and Apgar score at 1, 5, and 10 min; however, there was a significant difference in Apgar score after 1 min at 28-33⁺⁶ weeks (P=0.012).

CONCLUSIONS

The incidence rate of PPROM at our single center varied between 2012, 2014, and 2017. Risk factors for pregnancies complicated by PPROM include age, intrauterine infection, and vaginitis. The rate of CS delivery varied, and breech/transverse presentation was the major indication for patients with PPROM at 34-36⁺⁶ weeks.

The application of late amniocentesis: a retrospective study in a tertiary fetal medicine center in China

Background

To assess the indications and complications of late amniocentesis and the advanced genetic test results in a tertiary university fetal medical medicine unit.

Methods

In this retrospective study, women that underwent amniocentesis at 24^+ 0 to 39^+ 4 weeks, between January 2014 and December 2019, were recruited. Indications, complications, genetic test results, and pregnancy outcomes were reported for each pregnancy and compared with those who underwent the traditional amniocentesis at 16^+ 0 to 23^+ 6 weeks (control group). Information was retrieved from patient medical records, checked by research staff, and analyzed.

Results

Of the 1287 women (1321 fetuses) included in the late amniocentesis group, late detected sonographic abnormalities (85.5%) were the most common indication. The overall incidence of preterm birth and intrauterine demise after amniocentesis were 2.5 and 1.3%, respectively. Sixty-nine fetuses with aneuploidy (5.3%) and seventy-two fetuses with pathogenic copy number variations (5.5%) were identified by chromosomal microarray analysis. The maximal diagnostic yield (70%) was in the subgroup of fetuses with the abnormal diagnostic test results, followed by abnormal NIPT results (35.7%) and multiple abnormalities (23.8%). And 35.4% of the pregnancies were finally terminated.

Conclusions

Due to the high detection rates of advanced genetic technologies and the safety of the invasive procedure (3.9% vs 4.0%), it is reasonable to recommend late amniocentesis as an effective and reliable method to detect late-onset fetal abnormalities. However, chromosomal microarray and whole-exome sequencing may result in uncertain results like variants of uncertain significance. Comprehensive genetic counseling is necessary.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03723-7.

Performance of cell-free DNA sequencing-based non-invasive prenatal testing: experience on 36,456 singleton and multiple pregnancies

BACKGROUND

This paper describes the clinical practice and performance of cell-free DNA sequencing-based non-invasive prenatal testing (NIPT) as a screening method for fetal trisomy 21, 18, and 13 (T21, T18, and T13) and sex chromosome aneuploidies (SCA) in a general Italian pregnancy population.

METHODS

The AMES-accredited laboratory offers NIPT in maternal blood as a screening test for fetal T21, T18, T13 and SCA. Samples were sequenced on a NextSeq 550 (Illumina) using the VeriSeq NIPT Solution v1 assay.

RESULTS

A retrospective analysis was performed on 36,456 consecutive maternal blood samples, including 35,650 singleton pregnancies, 800 twin pregnancies, and 6 triplet pregnancies. Samples were tested between April 2017 and September 2019. The cohort included 46% elevated-risk and 54% low-risk patients. A result indicative of a classic trisomy was found in 356 (1%) of singleton or twin samples: 254 T21, 69 T18, and 33 T13. In addition, 145 results (0.4%) were indicative of a SCA. Of the combined 501 screen-positive cases, 484 had confirmatory diagnostic testing. NIPT results were confirmed in 99.2% (247/249) of T21 cases, 91.2% (62/68) of T18 cases, 84.4% (27/32) of T13 cases, and 86.7% (117/135) of SCA cases. In the 35,955 cases reported as unaffected by a classic trisomy or SCA, no false negative cases were reported. Assuming that false negative results would be reported, the sensitivity of NIPT was 100.00% for T21 (95% Cl 98.47-100.0), T18 (95% Cl 94.17-100.0), and T13 (95% Cl 87.54-100.0). The specificities were 99.99% (95% Cl 99.98-100.0), 99.98% (95% Cl 99.96-100.0), 99.99% (95% Cl 99.97-100.0), and 99.95% (95% Cl 99.92-99.97) for T21, T18, T13, and SCA, respectively.

CONCLUSION

This retrospective analysis of a large cohort of consecutive patients who had whole-genome sequencing-based NIPT for classic trisomies and SCA shows excellent detection rates and low false positive rates.

The Impact of Cell-Free DNA Analysis on the Management of Retinoblastoma

Retinoblastoma is a childhood eye cancer, mainly caused by mutations in the RB1 gene, which can be somatic or constitutional. Unlike many other cancers, tumour biopsies are not performed due to the risk of tumour dissemination. As a result, until recently, somatic genetic analysis was only possible if an affected eye was removed as part of a treatment. Several recent proof of principle studies have demonstrated that the analysis of tumour-derived cell-free DNA, either obtained from ocular fluid or blood plasma, has the potential to advance the diagnosis and influence the prognosis of retinoblastoma patients. It has been shown that a confirmed diagnosis is possible in retinoblastoma patients undergoing conservative treatment. In vivo genetic analysis of retinoblastoma tumours is also now possible, allowing the potential identification of secondary genetic events as prognostic biomarkers. In addition, noninvasive prenatal diagnosis in children at risk of inheriting retinoblastoma has been developed. Here, we review the current literature and discuss the potential impact of cell-free DNA analysis on both the diagnosis and treatment of retinoblastoma patients and their families.

Horizons in Veterinary Precision Oncology: Fundamentals of Cancer Genomics and Applications of Liquid Biopsy for the Detection, Characterization, and Management of Cancer in Dogs

Cancer is the leading cause of death in dogs, in part because many cases are identified at an advanced stage when clinical signs have developed, and prognosis is poor. Increased understanding of cancer as a disease of the genome has led to the introduction of liquid biopsy testing, allowing for detection of genomic alterations in cell-free DNA fragments in blood to facilitate earlier detection, characterization, and management of cancer through non-invasive means. Recent discoveries in the areas of genomics and oncology have provided a deeper understanding of the molecular origins and evolution of cancer, and of the "one health" similarities between humans and dogs that underlie the field of comparative oncology. These discoveries, combined with technological advances in DNA profiling, are shifting the paradigm for cancer diagnosis toward earlier detection with the goal of improving outcomes. Liquid biopsy testing has already revolutionized the way cancer is managed in human medicine - and it is poised to make a similar impact in veterinary medicine. Multiple clinical use cases for liquid biopsy are emerging, including screening, aid in diagnosis, targeted treatment selection, treatment response monitoring, minimal residual disease detection, and recurrence monitoring. This review article highlights key scientific advances in genomics and their relevance for veterinary oncology, with the goal of providing a foundational introduction to this important topic for veterinarians. As these technologies migrate from human medicine into veterinary medicine, improved awareness and understanding will facilitate their rapid adoption, for the benefit of veterinary patients.

The isolation and analysis of fetal nucleated red blood cells using multifunctional microbeads with a nanostructured coating toward early noninvasive prenatal diagnostics

Prenatal diagnostics holds great significance for pregnant women desiring healthy babies. Fetal nucleated red blood cells (fNRBCs), bearing the complete genome of the fetus, have been regarded as an important biomarker for noninvasive prenatal diagnostics (NIPD). The high-performance detection and enrichment of fNRBCs from maternal blood, especially during early pregnancy, is urgently needed for NIPD, which, unfortunately, remains a big challenge for early-pregnancy fNRBC isolation. In this study, we developed an innovative platform based on silica microbeads for fNRBC isolation and release in early pregnancy. Microbeads were coated with self-assembled MnO₂ nanoparticles (SiO₂@MnO₂) and then modified with a specific antibody. Benefiting from the three-dimensional nanostructure of the MnO₂ nanoparticles, the isolation efficiency of the fNRBCs was enhanced. Subsequently, fNRBCs were released via dissolving the MnO₂-nanoparticle coating using oxalic acid. We successfully isolated fNRBCs from the maternal peripheral blood samples of 20 pregnant women in the early pregnancy period, ranging from 41 to 62 gestational days. More importantly, the fetal origin of isolated cells was confirmed via fluorescent in situ hybridization and short tandem repeat analysis. This platform based on SiO₂@MnO₂ microbeads has verified the existence of fNRBCs in early-pregnancy maternal blood and is a promising approach for NIPD in early pregnancy.

Noninvasive Prenatal Paternity Testing with a Combination of Well-Established SNP and STR Markers Using Massively Parallel Sequencing

Cell-free fetal DNA (cffDNA) from maternal plasma has made it possible to develop noninvasive prenatal paternity testing (NIPPT). However, most studies have focused on customized single nucleotide polymorphism (SNP) typing systems and few have used conventional short tandem repeat (STR) markers. Based on massively parallel sequencing (MPS), this study used a widely-accepted forensic multiplex assay system to evaluate the effect of noninvasive prenatal paternity testing with a combination of well-established SNP and STR markers. Using a ForenSeq DNA Signature Prep Kit, NIPPT was performed in 17 real parentage cases with monovular unborn fetuses at 7 to 24 gestational weeks. Different analytical strategies for the identification of paternally inherited allele (PIA) were developed to deal with SNPs and STRs. Combined paternity index (CPI) for 17 real trios as well as 272 unrelated trios was calculated. With the combination of SNPs and A-STRs, 82.35% (14/17), 88.24% (15/17), 94.12% (16/17), and 94.12% (16/17) of real trios could be accurately determined when the likelihood ratio (LR) threshold for paternity inclusion was set to 10,000, 1000, 100, and 10, respectively. This reveals that simultaneous surveys of SNP and STR markers included in the ForenSeq DNA Signature Prep Kit offer a promising method for NIPPT using MPS technology.

Enrichment of Placental Trophoblast Cells from Clinical Cervical Samples Using Differences in Surface Adhesion on an Inclined Plane

Placental trophoblast cells present in cervical samples have great potential towards non-invasive prenatal testing. However, cervical samples are highly heterogeneous, largely comprised of maternal cervical cells with only a small quantity of trophoblast cells. In order to use these rare cells for diagnostic applications, there is a need to enrich and isolate them from the heterogeneous maternal sample. Our goal was to investigate the use of gravitational flow on an inclined surface and optimize parameters including angle of incline, surface material, incubation time on the surface, solution volume, and device channel width in order to identify a design allowing label-free enrichment of trophoblast cells. In this work we detail the development of a new method and device for controlling cell adhesion to a surface vs. rolling into a collection area. The enrichment device design was developed for ease of use by non-specialized personal and on a slide surface for the ability to be directly integrated onto an automatic cell picker instrument, which can be used for downstream single cell isolation. JEG-3 trophoblast cells were used with clinical cervical samples to present the effect of the different optimization parameters on enrichment. We further provide an assessment of the impact shear stress and thickness of the liquid layer has on cell enrichment. We found that this method provides a maximum JEG-3 enrichment using polystyrene surfaces at a 50° incline with a 5 min incubation period prior to inclined flow. This resulted in a 396 ± 52% increase in purity of the trophoblast cells from the clinical cervical samples as confirmed using human leukocyte antigen G (HLA-G) antibody staining with fluorescence imaging to identify JEG-3 cells. Ultimately, this method is inexpensive, quick, and has the potential for direct integration into fetal cell isolation platforms.

An examination of the influence of prenatal sex hormones on handedness: Literature review and amniotic fluid data

Competing theories have posited roles for foetal androgen exposure in the development of human handedness. However, due to practical and ethical considerations, few studies have used hormonal measures to examine this possibility. The current paper reviews this literature and reveals a generally inconsistent pattern of results. We also present data from a longitudinal study of prenatal sex hormone exposure and subsequent handedness. More specifically, we examine correlations between testosterone and estradiol measured from second trimester amniotic fluid and hand preference (Dutch language version of the Edinburgh Handedness Inventory) and hand skill asymmetry (pegboard task) measured at 15 years of age. Prenatal sex hormone exposure was not associated with the direction of hand preference in either males or females. However, in females, high levels of prenatal testosterone were associated with weaker lateralisation of hand skill, and high levels of prenatal estradiol were associated with weaker hand preference. In addition, high levels of prenatal testosterone were associated with increased task duration (i.e., slow hand speed) for the right and left hands of males. The pattern of results observed here is not entirely consistent with any of the main theories linking sex hormones with handedness, suggesting that an association between these variables may be more complex than initially thought.

Clinical utility of expanded non-invasive prenatal screening and chromosomal microarray analysis in high-risk pregnancy

OBJECTIVE

To evaluate the utility of expanded non-invasive prenatal screening (NIPS), compared with chromosomal microarray analysis (CMA), for the detection of chromosomal abnormalities in high-risk pregnancies.

METHODS

This was a multicenter retrospective study of singleton pregnancies at high risk for chromosomal abnormality. Patients who underwent expanded NIPS and CMA sequentially during pregnancy from 2015 to 2019 were included in the analysis. Pregnancies with a positive result for sex chromosome aneuploidy were excluded as the full details could not be retrieved. The utility of expanded NIPS and CMA for detection of chromosomal abnormalities in this cohort was compared by assessing the concordance between the results.

RESULTS

Of the 774 included high-risk pregnancies, 550 (71.1%) had a positive NIPS result, while a positive CMA result was detected in 308 (39.8%) cases. The rate of full or partial concordance between NIPS and CMA was 82.2%, 59.6% and 25.0% for trisomies 21, 18 and 13, respectively. For rare aneuploidies and segmental imbalances, NIPS and CMA results were fully or partially concordant in 7.5% and 33.3% of cases, respectively. Copy-number variants < 5 Mb were detected more often by CMA, with an incidence of 7.9% (61/774) compared with 3.1% (24/774) by NIPS. A genetic aberration was detected by CMA in 1 in 17 (5.8%) high-risk pregnancies that had a negative or non-reportable NIPS result.

CONCLUSION

CMA allows for comprehensive detection of genome-wide chromosomal abnormalities in high-risk pregnancies. CMA should be offered instead of expanded NIPS for high-risk pregnancies. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Patient attitudes toward prenatal diagnostic testing during antenatal care in an urban population

OBJECTIVE

Investigate factors that influence the decision to accept or decline diagnostic testing for pregnant women referred for genetic counseling.

METHODS

Cross sectional anonymous survey of pregnant women undergoing genetic counseling at a tertiary care referral center. Subjects' perceived risk of procedure related loss and fetal chromosomal problem were obtained via survey where patients rated risk from 0 (no risk) to 10 (highest risk).

RESULTS

There were no differences in sociodemographic factors between women undergoing a diagnostic procedure compared to those not undergoing a procedure. As the perceived risk for having a baby with genetic problem increased by one point, the estimated odds of having the diagnostic procedure increased by 43% controlling for the perceived risk of procedure related loss (p < .0001). Similarly, as the perceived risk of miscarriage increased by one point, the odds of having the diagnostic procedure decreased by 40%, controlling for the perceived risk of having a baby with a genetic problem (p < .0001). The main reason women cited for not undergoing a procedure was fear of procedure related loss.

CONCLUSIONS

Pregnant women that decline diagnostic testing have a higher perceived risk of procedure related loss and lower perceived risk of fetal chromosomal abnormality than those who accept.

Usefulness of copy number variant detection following monogenic disease exclusion in prenatal diagnosis

Aim

Families with an adverse history of monogenic disease focus on single‐gene diagnosis instead of low‐depth whole‐genome sequence, during subsequent pregnancies. The aim of this study was to assess the potential usefulness of low‐depth whole‐genome sequencing (copy number variant sequencing [CNV‐seq]) detection following monogenic disease exclusion in prenatal diagnosis.

Methods

A total of 285 families with a history of monogenic disease (of 41 different types; eliminated during the current pregnancy) were recruited and retrospectively analyzed. Low‐depth whole‐genome sequencing (CNV‐Seq, Next‐Seq CN500 platform) was performed for all fetuses.

Results

The CNV detection results of the 285 samples were as follows: one case of 18‐trisomy chimera (0.35%), one case of pathogenic 3q29 microdeletion syndrome CNV (0.35%), four cases of variant of uncertain significance (VUS) CNVs (1.40%), and four cases of Duchenne muscular dystrophy (DMD) carriers (1.40%); and the remaining samples were normal (96.15%). Of note, 2/285 (0.70%) samples still exhibited pathogenic abnormalities. All positive samples were followed up where the two cases of pathogenic abnormalities elected the pregnancy termination, while the four VUS cases and four DMD‐carrier cases were born healthy.

Conclusion

In cases where prenatal fetal monogenic disease has been ruled out, CNV detection is still beneficial and should be performed to prevent missed pathogenic CNVs. However, the costs need to be balanced against benefits, and the research will need to assess other types of testing.

A Pre-registered Meta-analysis Based on Three Empirical Studies Reveals No Association Between Prenatal (Amniotic) Cortisol Exposure and Fluctuating Asymmetry in Human Infants

Developmental instability (DI) reflects an organism’s inability to develop an ideal phenotype when challenged by genetic and environmental insults. DI can be estimated via the proxy measure of fluctuating asymmetry (FA), i.e., the small random deviations from perfect bilateral symmetry observed in the morphology of paired traits. The mechanisms involved in the genesis of FA in human populations are relatively unknown, though animal research indicates that hormonal processes may be involved. As maternal stress during pregnancy is detrimental to various developmental processes, elevated prenatal cortisol may represent a causal factor in the subsequent emergence of an asymmetrical phenotype. The main purpose of this pre-registered meta-analysis based on three empirical studies was to investigate whether mid-trimester amniotic cortisol levels predict subsequent FA in finger lengths of infants from Germany, Portugal, and the UK. No statistically significant relationships were observed, and meta-analytic combination of the effect size estimates yielded a null result. We did, however, detect significant positive correlations between the cortisol present in the amniotic fluid and maternal plasma in the Portuguese cohort, and observed that FA in the German cohort was significantly lower at 70-months than at either 9- or 20-months. Taken together, the current findings run contrary to animal research showing that elevated prenatal corticosterone exposure leads to increased FA. However, this may be because a single cortisol assay obtained via amniocentesis is an inadequate proxy for average gestational exposure, and/or that prenatal cortisol levels at an earlier (i.e., first rather than second trimester) stage of pregnancy is what explains variance in subsequent FA.

Decision-making factors in prenatal testing: A systematic review

This review examines the factors that affect the decision-making process of parental couples evaluating prenatal screening and diagnostic tests. A systematic search was performed using PubMed and PsycInfo databases. The 46 included studies had to: investigate the decision-making process about prenatal testing; focus on tests detecting trisomy 21, 18, 13, and abnormalities of sex chromosomes; be published in English peer-reviewed journals. The decision-making process seems composed of different levels: an individual level with demographic, clinical, and psychological aspects; a contextual level related to the technical features of the test and the information received; a relational level involving family and society.

Clinical Significance of Non-Invasive Prenatal Screening for Trisomy 7: Cohort Study and Literature Review

Trisomy 7 is the most frequently observed type of rare autosomal trisomies in genome-wide non-invasive prenatal screening (NIPS). Currently, the clinical significance of trisomy 7 NIPS-positive results is still unknown. We reviewed two independent cohorts from two laboratories where similar NIPS metrics were applied. A total of 70,441 singleton cases who underwent genome-wide NIPS were analyzed, among which 39 pregnancies were positive for trisomy 7, yielding a screen-positive rate of 0.055% (39/70,441). There were 28 cases with invasive testing results available; the positive predictive value (PPV) was 3.6% (1/28). We then searched the published NIPS studies to generate a large cohort of 437,873 pregnancies and identified 247 cases (0.056%) that were screened positive for trisomy 7. The overall PPV was 3.4% (4/118) in the combined data. The presence of uniparental disomy 7 was not detected in the NIPS trisomy 7-positive pregnancies with normal fetal karyotype. Among the 85 cases with pregnancy outcome available in combined data, 88.2% were normal live births, 14.1% had intrauterine growth restriction, preterm birth or low birth weight, 3.5% presented with ultrasound abnormality, and no fetal loss was observed. Our data provide valuable information for counseling and management of trisomy 7-positive NIPS pregnancies.

Screening for Aneuploidy in the Patient With Diabesity: Pearls and Pitfalls

The American College of Obstetrics & Gynecology (ACOG) recommends offering aneuploidy screening to all pregnant women. Obesity and diabetes are not associated with an increased risk of aneuploidy; however, they can complicate and compromise testing options. As the prevalence of obesity and diabetes, or "diabesity" increases, counseling women regarding potential limitations in testing performance of aneuploidy screening is of paramount importance. This chapter reviews options for aneuploidy screening for women with diabesity including sonography/nuchal translucency, serum analyte screening, and cell-free DNA. Potential challenges associated with diagnostic testing with amniocentesis and chorionic villus sampling in women with obesity are also discussed.

Pregnancy Loss After Amniocentesis and Chorionic Villus Sampling: Cohort Study

INTRODUCTION

Introduction: To estimate the procedure-related risks of pregnancy loss following chorionic villus sampling (CVS) and amniocentesis (AC) compared to pregnancies without procedure.

METHODS

This cohort study enrolled all women who underwent CVS or AC at the Department of Perinatology, University Medical Centre, Ljubljana, Slovenia (from January 2013 to June 2015). For each group we obtained a maternal age and gestational age (11-14 weeks for CVS and >15 weeks for AC) for a matched control group without invasive procedures from the national database. The data was obtained from hospital records and telephone surveys concerning pregnancy outcomes. Pregnancy loss rates in intervention vs. control groups were compared by generating relative risk (RR) with a 95% confidence interval.

RESULTS

During the study period, 828 women underwent CVS and 2,164 women underwent AC. Complete outcome data was available in 2,798 cases (93.5%, 770 CVS, 2,028 AC). Pregnancy loss occurred in 8/770 (1.04%, 95% CI 0.4-2.0%) after CVS vs. 15/1130 (1.33%, 95% CI 0.8-2.2%) in matched control (RR 0.8, 95% CI 0.33-1.8, p=0.6). It occurred in 16/2028 (0.79%, 95% CI 0.5-1.3%) after AC vs. 14/395 (3.29%, 95% CI 2.1-5.8%) in matched control (RR 0.2, 95% CI 0.11-0.45, p<0.0001).

CONCLUSION

The pregnancy loss rates after CVS and AC were comparable to losses in pregnancies without these procedures. With the increasing use of non-invasive prenatal testing, information that the invasive procedures are safe when indicated is essential.

Applications of noninvasive prenatal testing in vanishing twin syndrome pregnancies after treatment of assisted reproductive technology in a single center

OBJECTIVE

The objective of the study is to assess the clinical application of noninvasive prenatal testing (NIPT) for VTS pregnancies after the treatment of assisted reproductive technology (ART).

METHOD

This was a retrospective study on VTS pregnancies through ART treatment. Participants underwent NIPT at 11 to 13 weeks gestation by sequencing. Resampling was recommended for both positive and testing failure cases. For NIPT positive results, participants were advised to have invasive testing. Clinical outcomes were obtained by telephone interview.

RESULTS

In total of 579 cases, testing failure rates after first sampling and resampling were 7.6% and 1.4%, respectively. Twelve positive results were reported by NIPT. But only one true positive was confirmed, giving a PPV of 8%. A total of 576 cases completed the follow-up (including 533 NIPT negative, 12 positive, and 31 testing failure) and three cases lost follow-up. Among the 536 cases with NIPT negative results, 504 (94.0%) resulted in live-birth and 29 (5.4%) resulted in miscarriage or stillbirths. No false-negative result was reported.

CONCLUSION

NIPT has the potential to be used in prenatal screening for VTS pregnancies. For the pregnant women who obtained positive and testing failure results, resampling after 15 weeks of gestation is recommended.

The reduced use of invasive procedures leads to a change of frequencies of prenatally detected chromosomal aberrations: population data from the years 2012-2016

OBJECTIVE

The aim of the study was to analyze the results of screening for chromosomal aberrations in a population with a high rate of first-trimester screening and low rate of cell-free DNA testing.

METHODS

The data were obtained from the National Registry of Congenital Anomalies of the Czech Republic. We calculated and compared the proportion of autosomal trisomies (Down, Edwards, and Patau syndrome) and of other chromosomal aberrations identified during prenatal diagnostics.

RESULTS

We identified 3009 prenatally diagnosed cases of chromosomal aberrations in the 2012-2016 period. The number of major autosomal trisomies has increased from 329 cases (30.86 per 10,000 live births) in 2012 to 423 cases (37.41) in 2016 (p = 0.014). The numbers of other aberrations decreased from 246 cases (23.07 per 10,000) in 2012 to 217 cases (19.19) in 2016 (p = 0.017). The usage of invasive diagnostic procedures decreased from 1099.54 in 2012 to 622.73 in 2016 (per 10,000 live births).

CONCLUSIONS

Our population-based study confirmed a decrease in prenatal detection of nonmajor chromosomal aberrations wherein a decrease of invasive testing occurred. With the introduction of cell-free DNA testing, further decrease of invasive procedures and detection of nonmajor aberrations may be expected.