Amniocentesis and chorionic villus sampling for prenatal diagnosis

Distinct maternofetal immune signatures delineate preterm birth onset following urinary tract infection

Preterm birth is the leading cause of infant mortality resulting in over one million neonatal deaths annually. Maternal urinary tract infection (UTI) during pregnancy increases risk for preterm birth; however, biological processes mediating UTI-associated preterm birth are not well-described. We established a murine maternal UTI model in which challenge with uropathogenic E. coli resulted in preterm birth in about half of dams. Dams experiencing preterm birth displayed excessive bladder inflammation and altered uteroplacental T cell polarization compared to non-laboring infected dams, with no differences in bacterial burdens. Additional factors associated with preterm birth included higher proportions of male fetuses and lower maternal serum IL-10. Furthermore, exogenous maternal IL-10 treatment absolved UTI-associated preterm birth but contributed to fetal growth restriction in this model. Using urine samples from a cohort of human pregnancies with or without UTI, we correlated urinary cytokines with birth outcomes and urine culture status. These analyses yielded a non-invasive, highly predictive three-model system for evaluating preterm birth risk implicating cytokines IL-10, IL-15, IL-1β, and IL-1RA. Our unique bimodal murine model coupled with patient samples provides a platform to investigate immunological and microbial factors governing UTI-associated preterm birth, revealing novel therapeutic opportunities to predict or prevent preterm birth.

Comparative analysis of obstetric, perinatal, and neurodevelopmental outcomes following chorionic villus sampling and amniocentesis

Background

The risks of invasive prenatal tests are reported in previous studies such as miscarriage, fetal anomalies, and bleeding. However, few compare short-term and long-term outcomes between invasive tests. This study aims to investigate obstetric, perinatal, and children's neurodevelopmental outcomes following chorionic villus sampling (CVS) or amniocentesis in singleton pregnancy.

Methods

This retrospective cohort study included healthy singleton pregnancies underwent transabdominal CVS (gestational age [GA] at 10-13 weeks) or amniocentesis (GA at 15-21 weeks) at a single medical center between 2012 and 2022. Only cases with normal genetic results were eligible. Short-term and long-term neurodevelopmental outcomes were evaluated.

Results

The study included 200 CVS cases and 498 amniocentesis cases. No significant differences were found in body mass index, parities, previous preterm birth, conception method, and cervical length (CL) before an invasive test between the groups. Rates of preterm labor, preterm premature rupture of the membranes, preterm birth, neonatal survival, neonatal short-term morbidities, and long-term neurodevelopmental delay were similar. However, the CVS group had a higher rate of cervical cerclage due to short CL before 24 weeks (7.0%) compared to the amniocentesis group (2.4%). CVS markedly increased the risk of cervical cerclage due to short CL (adjusted odd ratio [aOR] = 3.17, 95%CI [1.23-8.12], p = 0.016), after considering maternal characteristics.

Conclusion

Performing CVS resulted in a higher incidence of cerclage due to short cervix or cervical dilatation compared to amniocentesis in singleton pregnancies. This highlights the importance of cautious selection for CVS and the necessity of informing women about the associated risks beforehand.

MaterniCode: New Bioinformatic Pipeline to Detect Fetal Aneuploidies and Rearrangements Using Next-Generation Sequencing

Objective: The present study is aimed at introducing and evaluating MaterniCode, a state-of-the-art bioinformatic pipeline for noninvasive prenatal testing (NIPT) that leverages the Ion Torrent semiconductor sequencing platform. The initiative strives to revolutionize prenatal diagnostics by offering a rapid and cost-effective method without sacrificing accuracy. Methods: Two distinct bioinformatic strategies were employed for fetal sex determination, one of which achieved 100% accuracy. We analyzed 1225 maternal blood samples for fetal aneuploidies, benchmarking against the industry standard Illumina VeriSeq™ NIPT Solution v2. The capability of MaterniCode to detect and characterize complex chromosomal anomalies was also assessed. Results: MaterniCode achieved near-perfect accuracy in fetal sex determination through chromosome Y (chrY )-specific gene analysis, whereas the alternative method, employing the ratio of high-quality mapped reads on chrY relative to all reads, delivered 100% accuracy. For fetal aneuploidy detection, both the integrated WisecondorX and NIPTeR algorithms demonstrated a 100% sensitivity and specificity rate, consistent with Illumina VeriSeq™ NIPT Solution v2. The pipeline also successfully identified and precisely mapped significant chromosomal abnormalities, exemplified by a 2.4 Mb deletion on chromosome 13 and a 3 Mb duplication on chromosome 2. Conclusion: MaterniCode has proven to be an innovative and highly efficient tool in the domain of NIPT, demonstrating excellent sensitivity and specificity. Its robust capability to effectively detect a wide range of complex chromosomal aberrations, including rare and subtle variations, positions it as a promising and valuable addition to prenatal diagnostic technologies. This enhancement to diagnostic precision significantly aids clinicians in making informed decisions during pregnancy management.

Absent or hypoplastic nasal bone: What to tell the prospective parents?

BACKGROUND

Absent or hypoplastic nasal bone (AHNB) on first or second-trimester ultrasonography (USG) is an important soft marker of Down syndrome. However, due to its varied incidence in euploid and aneuploid fetuses, there is always a dilemma of whether to go for invasive fetal testing for isolated AHNB. This study aims to assess outcomes specifically within the context of Indian ethnicity women.

MATERIALS AND METHODS

This was a prospective observational study. All patients who reported with AHNB in the first- or second-trimester USG were included. Genetic counseling was done, and noninvasive and invasive testing was offered. Chromosomal anomalies were meticulously recorded, and pregnancy was monitored.

RESULTS

The incidence of AHNB in our study was 1.16% (47/4051). Out of 47 women with AHNB, the isolated condition was seen in 32 (0.78%) cases, while AHNB with structural anomalies was seen in nine cases (0.22%). Thirty-nine women opted for invasive testing. Six out of 47 had aneuploidy (12.7%), while two euploid cases (4.25%) developed nonimmune hydrops. The prevalence of Down syndrome in fetuses with AHNB was 8.5% (4/47) and 0.42% (17/4004) in fetuses with nasal bone present. This difference was statistically significant (p = .001).

CONCLUSION

The results indicate that isolated AHNB cases should be followed by a comprehensive anomaly scan rather than immediately recommending invasive testing. However, invasive testing is required when AHNB is associated with other soft markers or abnormalities. As chromosomal microarray is more sensitive than standard karyotype in detecting chromosomal aberrations, it should be chosen over karyotype.

Gender equity in hemophilia: need for healthcare, familial, and societal advocacy

Hemophilia is a rare bleeding disorder caused by a genetic defect on chromosome X. It is inherited as an X-linked trait, and hence, it is more frequently diagnosed in males, whereas women have been traditionally considered only as carriers of the disease. However, the role of women in families of patients with hemophilia is pivotal. As mothers, sisters, daughters, and female partners of patients with hemophilia, they play a central role in the management of the patient, considering healthcare, social, and familial aspects, but they might be affected by the disease as well, particularly in regions where consanguinity is frequent. This paper aims to explore the involvement of women in hemophilia, including their carrier status, bleeding symptoms, treatment challenges, and psychosocial impact not only related to male patients, but also as patients affected with hemophilia themselves. We advocate health equity, equal access to healthcare for men and women with hemophilia and dedicated resources to improve the unique needs of the women dealing with hemophilia, ultimately leading to improved care and quality of life.

Congenital anomalies of the kidney and urinary tract: antenatal diagnosis, management and counselling of families

Congenital anomalies of the kidney and urinary tract are collectively one of the most commonly diagnosed antenatal conditions. Clinicians have several tools available to diagnose anomalies, including imaging, biomarkers, family history and genetic studies. In certain cases, antenatal interventions such as vesico-amniotic shunting may be considered to improve postnatal outcomes.Congenital kidney anomalies detected antenatally can vary in clinical significance from almost no impact postnatally to significant morbidity and perinatal mortality. Prognosis broadly depends on kidney size, structure and amount of amniotic fluid, alongside genetics and family history, and progression on subsequent scans. It is important to counsel parents appropriately using a parent-focused and personalised approach. The use of a multidisciplinary team should always be considered.

Combining deep learning and intelligent biometry to extract ultrasound standard planes and assess early gestational weeks

OBJECTIVES

To develop and validate a fully automated AI system to extract standard planes, assess early gestational weeks, and compare the performance of the developed system to sonographers.

METHODS

In this three-center retrospective study, 214 consecutive pregnant women that underwent transvaginal ultrasounds between January and December 2018 were selected. Their ultrasound videos were automatically split into 38,941 frames using a particular program. First, an optimal deep-learning classifier was selected to extract the standard planes with key anatomical structures from the ultrasound frames. Second, an optimal segmentation model was selected to outline gestational sacs. Third, novel biometry was used to measure, select the largest gestational sac in the same video, and assess gestational weeks automatically. Finally, an independent test set was used to compare the performance of the system with that of sonographers. The outcomes were analyzed using the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and mean similarity between two samples (mDice).

RESULTS

The standard planes were extracted with an AUC of 0.975, a sensitivity of 0.961, and a specificity of 0.979. The gestational sacs' contours were segmented with a mDice of 0.974 (error less than 2 pixels). The comparison showed that the relative error of the tool in assessing gestational weeks was 12.44% and 6.92% lower and faster (min, 0.17 vs. 16.6 and 12.63) than that of the intermediate and senior sonographers, respectively.

CONCLUSIONS

This proposed end-to-end tool allows automatic assessment of gestational weeks in early pregnancy and may reduce manual analysis time and measurement errors.

CLINICAL RELEVANCE STATEMENT

The fully automated tool achieved high accuracy showing its potential to optimize the increasingly scarce resources of sonographers. Explainable predictions can assist in their confidence in assessing gestational weeks and provide a reliable basis for managing early pregnancy cases.

KEY POINTS

• The end-to-end pipeline enabled automatic identification of the standard plane containing the gestational sac in an ultrasound video, as well as segmentation of the sac contour, automatic multi-angle measurements, and the selection of the sac with the largest mean internal diameter to calculate the early gestational week. • This fully automated tool combining deep learning and intelligent biometry may assist the sonographer in assessing the early gestational week, increasing accuracy and reducing the analyzing time, thereby reducing observer dependence.

Non-invasive prenatal testing: a revolutionary journey in prenatal testing

Non-invasive prenatal testing (NIPT) is a pioneering technique that has consistently advanced the field of prenatal testing to detect genetic abnormalities and conditions with the aim of decreasing the incidence and prevalence of inherited conditions. NIPT remains a method of choice for common autosomal aneuploidies, mostly trisomy 21, and several monogenic disorders. The advancements in gene sequencing techniques have expanded the panel of conditions where NIPT could be offered. However, basic research on the impact of several genetic conditions lags behind the methods of detection of these sequence aberrations, and the impact of the expansion of NIPT should be carefully considered based on its utility. With interest from commercial diagnostics and a lack of regulatory oversight, there remains a need for careful validation of the predictive values of different tests offered. NIPT comes with many challenges, including ethical and economic issues. The scientific evidence, technical feasibility, and clinical benefit of NIPT need to be carefully investigated before new tests and developments are translated into clinical practice. Moreover, the implementation of panel expansion of NIPT should accompany expert genetic counseling pre- and post-testing.

DEGUM Recommendations on Diagnostic Puncture in Prenatal Medicine

Diagnostic puncture (amniocentesis, chorionic villus sampling, and fetal blood sampling) is an essential part of prenatal diagnostics and the only established and sufficiently scientifically evaluated possibility of diagnosing genetic diseases from pregnancy-specific cells. The number of diagnostic punctures in Germany, as in other countries, has fallen significantly. This is largely due to the introduction of first-trimester screening with further detailed ultrasound examination of the fetus and the analysis of cf-DNA (cell-free DNA) from maternal blood (noninvasive prenatal test - NIPT). On the other hand, knowledge about the incidence and appearance of genetic diseases has increased. The development of modern molecular genetic techniques (microarray and exome analysis) makes a differentiated investigation of these diseases increasingly possible. The requirements for education and counseling regarding these complex correlations have thus increased. The studies performed in recent years make it clear that diagnostic puncture performed in expert centers is associated with a low risk of complications. In particular, the procedure-related miscarriage risk hardly differs from the background risk for spontaneous abortion. In 2013, the Section of Gynecology and Obstetrics of the German Society for Ultrasound in Medicine (DEGUM) published recommendations on diagnostic puncture in prenatal medicine 1. The developments described above and new findings in recent years make it necessary to revise and reformulate these recommendations. The aim of this review is to compile important and current facts regarding prenatal medical puncture (including technique, complications, genetic examinations). It is intended to provide basic, comprehensive, and up-to-date information on diagnostic puncture in prenatal medicine. It replaces the publication from 2013 1.

Evaluation of Fetal and Maternal Outcomes in Chorion Villus Sampling (CVS)

Background

Chorionic villus sampling (CVS) is one of the invasive diagnostic methods used to diagnose chromosomal, genetic, and metabolic diseases in the embryonic period. The use of this method is associated with maternal and fetal consequences, the most serious of which is abortion. Therefore, the present study was conducted to investigate the incidence of these consequences and the factors affecting the incidence of abortion.

Materials and Methods

A cross-sectional study was performed on 98 pregnant women with CVS indications. Maternal and fetal outcomes including abortion, vaginal bleeding, subchorionic hematoma, premature rupture of membrane (PROM), chorioamnionitis, preterm delivery, limb abnormality, fetal growth retardation, and preeclampsia were recorded.

Results

The results of the present study showed that the incidence of fetal outcomes including fetal growth failure, premature rupture of membranes, abortion, and limb abnormalities was 4.1%, 7.1%, 3.1%, and 1%, and the incidence of maternal outcomes including preterm delivery, subchorionic hematoma, preeclampsia, and hemorrhage was 14.3%, 3.1%, 6.1%, and 10.2%, respectively. In addition, a decrease in free BHCG and an increase in NT were significantly associated with the occurrence of abortion (OR: 0.11 and 4.25, respectively, P value < 0.05).

Conclusion

It should be noted that due to a long time between placental sampling and the occurrence of vaginal bleeding, premature rupture of membrane, and preterm delivery, it seems that placental sampling has no effect. In addition, only a decrease in free BHCG or an increase in NT significantly increased the chance of miscarriage.

Single-cell whole-genome sequencing, haplotype analysis in prenatal diagnosis of monogenic diseases

Monogenic inherited diseases are common causes of congenital disabilities, leading to severe economic and mental burdens on affected families. In our previous study, we demonstrated the validity of cell-based noninvasive prenatal testing (cbNIPT) in prenatal diagnosis by single-cell targeted sequencing. The present research further explored the feasibility of single-cell whole-genome sequencing (WGS) and haplotype analysis of various monogenic diseases with cbNIPT. Four families were recruited: one with inherited deafness, one with hemophilia, one with large vestibular aqueduct syndrome (LVAS), and one with no disease. Circulating trophoblast cells (cTBs) were obtained from maternal blood and analyzed by single-cell 15X WGS. Haplotype analysis showed that CFC178 (deafness family), CFC616 (hemophilia family), and CFC111 (LVAS family) inherited haplotypes from paternal and/or maternal pathogenic loci. Amniotic fluid or fetal villi samples from the deafness and hemophilia families confirmed these results. WGS performed better than targeted sequencing in genome coverage, allele dropout (ADO), and false-positive (FP) ratios. Our findings suggest that cbNIPT by WGS and haplotype analysis have great potential for use in prenatally diagnosing various monogenic diseases.

Case report and discussion: Pre-implantation genetic diagnosis with surrogacy in vascular Ehlers–Danlos syndrome

Introduction: Vascular Ehlers–Danlos syndrome (vEDS) is an autosomal dominant inherited connective tissue condition, characterized by generalized tissue fragility with an increased risk of arterial dissection and hollow organ rupture. In women with vEDS, pregnancy and childbirth carry significant risks of both morbidity and mortality. The Human Fertilisation and Embryology Authority has approved vEDS for pre-implantation genetic diagnosis (PGD), given the potential for life-limiting complications. PGD avoids implantation of embryos that are affected by specific disorders by carrying out genetic testing (either for a familial variant or whole gene) and selecting unaffected embryos prior to implantation.

Case: We present an essential clinical update to the only published clinical case of a woman with vEDS undergoing PGD with surrogacy, initially through stimulated in vitro fertilization (IVF) and in vitro maturation (IVM) and subsequently through natural IVF.

Discussion: In our experience, a subset of women with vEDS do wish to have biological, unaffected children through PGD despite being aware of the risks of pregnancy and delivery. Given the clinical heterogeneity in vEDS, these women could be considered on a case-by-case basis for PGD. Controlled studies with comprehensive patient monitoring evaluating the safety of PGD are essential to equitable healthcare provision.

Implications for Prenatal Genetic Testing in the United States After the Reversal of Roe v Wade

Prenatal genetic screening and diagnostic testing should be offered to every pregnant individual, with methods varying based on gestational age. Since Roe v Wade was overturned in June 2022, many states have implemented gestational age-based abortion restrictions. It is critical that reproductive health care professionals be aware of the interaction between the timing of genetic screening and diagnostic testing and the availability of legal abortion services in their state. We examined individual state abortion restrictions per publicly available data from The New York Times and the Guttmacher Institute and reviewed which genetic screening and diagnostic tests could be performed to provide results in time for individuals to decide whether to terminate their pregnancies legally in each state. As of December 11, 2022, 14 states have restrictions in which no diagnostic testing could be completed before gestational age-based cutoffs. Gestational age-based abortion restrictions may also influence a patient to favor chorionic villous sampling (CVS) over amniocentesis. There are two states, Florida and Arizona, where CVS would be feasible before the state's gestational age limit on abortion but amniocentesis would not. Both CVS and amniocentesis are feasible in 35 states, with legal challenges pending in 8 of the 35. Seven states specifically prohibit abortion for fetuses with genetic abnormalities. Clinicians may be placed in the suboptimal position of counseling patients with screening results alone before the gestational age-based ban in their state. There are several potential downstream consequences of gestational age-based termination restrictions for current genetic screening and testing paradigms, from adjustments to counseling options to potentially higher CVS procedure rates. Clinicians should be prepared for practice patterns to change to best serve patients in this evolving legal context.

Performance of expanded non-invasive prenatal testing for fetal aneuploidies and copy number variations: A prospective study from a single center in Jiangxi province, China

To evaluate the performance of expanded non-invasive prenatal testing (expanded noninvasive prenatal testing, NIPT-Plus) in screening for fetal chromosomal abnormalities includes aneuploidies and copy number variations, a total of 23,116 pregnant women with a singleton pregnancy were recruited for NIPT-Plus. Screening positive results were verified by karyotype analysis and chromosomal microarray analysis after amniocentesis. A total of 264 pregnancies (1.14%) were positive results as predicted by NIPT-Plus, including 233 aneuploidies and 31 copy number variations. Following genetic counseling, 233 (88.26%) pregnant women underwent invasive prenatal diagnosis and 136 were verified as true positives, comprising 72 common trisomies (T21, T18, T13), 47 sex chromosomal abnormalities two rare autosomal aneuploidies (RATs) and 15 copy number variations The positive predictive value for common trisomies, SCAs, RATs and CNVs were 68.57%, 68.12%, 6.67% and 51.72%, respectively. Pregnant women with screen-positive results for common trisomies have higher rates of invasive prenatal diagnosis and pregnancy termination than those with positive results for SCAs, RATs, and CNVs. NIPT-Plus showed a good performance in detecting common trisomies, SCAs and also contributed to detecting pathogenic CNVs, but higher accuracy was required in the detection of RATs. In summary, this study provides a reference for the clinical application of NIPT-Plus for screening fetal chromosomal abnormalities in this region. Therefore, we suggest that NIPT-Plus could be widely used in clinical screening for fetal chromosomal abnormalities in combination with prenatal diagnosis and genetic counseling.

Inconsistency between non-invasive prenatal testing (NIPT) and conventional prenatal diagnosis due to confined placental and fetal mosaicism: Two case reports

We aimed to identify the causes of inconsistent results between non-invasive prenatal testing (NIPT) and invasive testing methods for trisomy 21. In the first case, NIPT was performed at 11 weeks of pregnancy, and the result showed a high risk of trisomy 21 [fetal fraction (FF) = 6.98%, 21 chromosome Z-score = 3.6]. The patient underwent quantitative fluorescent (QF)-PCR and karyotyping at 14 + 0 weeks of pregnancy through CVS showing mosaicism of 47, XX, + 21[11] and 46, XX [39] in karyotyping. The patient underwent amniocentesis at 15 + 6 weeks, showing a normal pattern in QF-PCR and 46, XX karyotyping in long term culture. The second case underwent NIPT at 16 + 5 weeks of pregnancy (FF = 7.52%, 21 chromosome Z-score = 2.503). She underwent an invasive test at 19 weeks through amniotic fluid sampling. As a result, trisomy 21 was detected by QF-PCR, and mosaicism of XX, +21[22]/46, XX [4] was identified by karyotyping. Despite significant advances in fetal chromosome analysis using NIPT, invasive testing is still needed as placenta-derived DNA does not reflect 100% fetal genetic information. Placental mosaicism can be detected by NIPT, but more research is needed to increase its sensitivity. Therefore, if the NIPT result is positive, an invasive test can confirm the result, and continuous monitoring is required even if the NIPT result is negative.

Efficacy of lidocaine local anesthesia on pain perception during amniocentesis: A meta-analysis of randomized controlled trials

To evaluate the efficacy of lidocaine local analgesia on maternal pain reduction during amniocentesis. Web of Science, Scopus, PubMed, and CENTRAL databases were screened from inception and updated in July 2022. The included randomized controlled trials (RCTs) were evaluated for the risk of bias via the Cochrane tool. The primary outcome was pain perception using the 10 cm visual analog scale, and was summarized as mean difference (MD) with 95% confidence interval (CI) in a random-effects model. Subgroup analysis was performed according to the mode of administration. Meta-analysis was done via Review Manager software. We included five RCTs totaling 1004 women (lidocaine arm n=502 patients and control arm n=502 patients). Overall, there was no significant difference between both arms [MD=-0.21, 95% CI (-0.48, 0.07), p=0.80]. The pooled analysis showed homogeneity (p=0.13, I2=43%). Subgroup analysis according to the mode of administration showed that pain perception did not significantly differ between both arms when lidocaine was employed as injection [n=3 RCTs, MD=-0.26, 95% CI (-0.76, 0.23), p=0.29] or non-injection [n=2 RCTs, MD=-0.18, 95% CI (-0.55, 0.18), p=0.33]. The pooled analyses showed heterogeneity (p=0.05, I2=66%) and homogeneity (p=0.27, I2=19%), respectively. There was no noteworthy change concerning maternal pain perception between the lidocaine and control arms. Most women reported just minimal discomfort during amniocentesis. Counseling should educate patients that the pain they might experience during amniocentesis is comparable to venous blood sampling.

Non-invasive prenatal testing in Germany: a unique ethical and policy landscape

Non-invasive prenatal testing (NIPT) has been available commercially in Europe since approximately 2012. Currently, many countries are in the process of integrating NIPT into their publicly funded healthcare systems to screen for chromosomal aneuploidies such as trisomy 21 (Down syndrome), with a variety of implementation models. In 2019, the German Federal Joint Committee (G-BA), which plays a significant role in overseeing healthcare decisions in Germany, recommended that NIPT be reimbursed through public insurance. Following this recommendation, NIPT will be offered on a case-by-case basis, when a pregnant woman, after being counselled, makes an informed decision that the test is necessary in her personal situation. This model differs significantly from many other European countries, where NIPT is being implemented either as a first-tier screening offer available for all pregnancies, or a contingent screen for those with a high probability of foetal aneuploidy (with varying probability cut-offs). In this paper we examine how this unique approach to implementing NIPT in Germany is produced by an ethical and policy landscape resulting from a distinctive cultural and historical context with a significant influence on healthcare decision-making. Due in part to the specific legal and regulatory environment, as well as strong objections from various stakeholders, Germany did not implement NIPT as a first-tier screen. However, as Germany does not currently publicly fund as standard other forms of prenatal aneuploidy screening (such as combined first trimester screening), neither can it be implemented as a screen contingent on specific probability cut-offs. We discuss how German policy reflects the echoes of the past shaping approaches to new biotechnologies, and the implications of this unique model for implementing NIPT in a public healthcare system.

Non-invasive prenatal diagnosis (NIPD): how analysis of cell-free DNA in maternal plasma has changed prenatal diagnosis for monogenic disorders

Cell-free fetal DNA (cffDNA) is released into the maternal circulation from trophoblastic cells during pregnancy, is detectable from 4 weeks and is representative of the entire fetal genome. The presence of this cffDNA in the maternal bloodstream has enabled clinical implementation of non-invasive prenatal diagnosis (NIPD) for monogenic disorders. Detection of paternally inherited and de novo mutations is relatively straightforward, and several methods have been developed for clinical use, including quantitative polymerase chain reaction (qPCR), and PCR followed by restriction enzyme digest (PCR-RED) or next-generation sequencing (NGS). A greater challenge has been in the detection of maternally inherited variants owing to the high background of maternal cell-free DNA (cfDNA). Molecular counting techniques have been developed to measure subtle changes in allele frequency. For instance, relative haplotype dosage analysis (RHDO), which uses single nucleotide polymorphisms (SNPs) for phasing of high- and low-risk alleles, is clinically available for several monogenic disorders. A major drawback is that RHDO requires samples from both parents and an affected or unaffected proband, therefore alternative methods, such as proband-free RHDO and relative mutation dosage (RMD), are being investigated. cffDNA was thought to exist only as short fragments (<500 bp); however, long-read sequencing technologies have recently revealed a range of sizes up to ∼23 kb. cffDNA also carries a specific placental epigenetic mark, and so fragmentomics and epigenetics are of interest for targeted enrichment of cffDNA. Cell-based NIPD approaches are also currently under investigation as a means to obtain a pure source of intact fetal genomic DNA.

Invasive Prenatal Diagnostic Testing for Aneuploidies in Singleton Pregnancies: A Comparative Review of Major Guidelines

Sophisticated screening protocols for genetic abnormalities constitute an important component of current prenatal care, aiming to identify high-risk pregnancies and offer appropriate counseling to parents regarding their options. Definite prenatal diagnosis is only possible by invasive prenatal diagnostic testing (IPDT), mainly including amniocentesis and chorionic villous sampling (CVS). The aim of this comparative review was to summarize and compare the existing recommendations on IPDT from the most influential guidelines. All the reviewed guidelines highlight that IPDT is indicated based on a positive screening test rather than maternal age alone. Other indications arise from medical history and sonography, with significant variations identified between the guidelines. The earlier time for amniocentesis is unequivocally set at ≥15 gestational weeks, whereas for CVS, the earlier limit varies from ≥10 to ≥11 weeks. Certain technical aspects and the overall approach demonstrate significant differences. Periprocedural management regarding Rhesus alloimmunization, virologic status and use of anesthesia or antibiotics are either inconsistent or insufficiently addressed. The synthesis of an evidence-based algorithm for IPDT is of crucial importance to healthcare professionals implicated in prenatal care to avoid unnecessary interventions without compromising optimal prenatal care.

Effect of gestational age at laser therapy on perinatal outcome in monochorionic diamniotic pregnancies affected by twin-to-twin transfusion syndrome

OBJECTIVE

To evaluate the effect of gestational age at laser therapy for twin-to-twin transfusion syndrome (TTTS) on perinatal outcome.

DESIGN AND SETTINGS

Single retrospective observational cohort.

POPULATION

All consecutive pregnancies affected by TTTS and referred to our department between January 2013 and August 2020.

METHODS

Gestational age was modelled both as a categorical and as a continuous variable. Log-binomial regression was used to estimate the odds ratios (crude and adjusted for placental location, Quintero stage and cervical length) as well as the adjusted predicted probability of survival and fetal loss according to gestational age at laser therapy.

MAIN OUTCOMES

Fetal and neonatal survival, preterm prelabour rupture of membranes (PPROM).

RESULTS

Of the 503 pregnancies referred for TTTS, 431 were treated by laser therapy. Gestational age at laser therapy was positively and significantly associated with the overall survival at birth and at discharge (adjusted odds ratio [aOR] 1.12, 95% CI 1.05-1.19), as with a reduction in double fetal loss (aOR 0.81, 95% CI 0.71-0.92). Conversely, the rate of PPROM before 24 weeks was significantly higher in early cases (32% of PPROM <24 weeks when laser therapy was performed before 17 weeks versus 1.5% after 22 weeks, p < 0.001, aOR 0.60, 95% CI 0.48-0.72). Among the survivors, preterm birth before 28 weeks was significantly related to the gestational age at laser (OR 0.91, 95% CI 0.84-0.99), resulting in a significant impact on neonatal morbidity (OR 0.91, 95% CI 0.85-0.97).

CONCLUSION

Our results suggest a significant and independent impact of the gestational age at laser surgery on perinatal survival, PPROM and neonatal morbidity.

Noninvasive prenatal diagnosis based on cell-free DNA for tuberous sclerosis: A pilot study

BACKGROUND

Noninvasive prenatal diagnosis (NIPD) based on cell-free DNA (cfDNA) has been introduced into the clinical application for some monogenic disorders but not for tuberous sclerosis (TSC) yet, which is an autosomal dominant disease caused by various variations in TSC1 or TSC2 gene. We aimed to explore the feasibility of NIPD on TSC.

METHODS

We recruited singleton pregnancies at risk of TSC from 14 families with a proband child. Definitive NIPD for TSC was performed using targeted next-generation sequencing of cfDNA in parallel with maternal white blood cell DNA (wbcDNA). The NIPD results were validated by amniocentesis or postnatal gene testing and follow-up of the born children.

RESULTS

Missense mutations, nonsense mutations, frameshift mutations, and splice-site variants which were obtained through de-novo, maternal, or paternal inheritance were included. The mean and minimum gestational weeks of NIPD were 17.18 ± 5.83 and 8 weeks, respectively. The NIPD results were 100% consistent with the amniocentesis or postnatal gene testing and follow-up of the born children.

CONCLUSION

This study demonstrates that NIPD based on cfDNA is feasible for TSC, but required to be confirmed with more samples. Studies on TSC can contribute to the application and promotion of NIPD for monogenic disorders.

Prenatal dexamethasone treatment for classic 21-hydroxylase deficiency in Europe

OBJECTIVE

To assess the current medical practice in Europe regarding prenatal dexamethasone (Pdex) treatment of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency.

DESIGN AND METHODS

A questionnaire was designed and distributed, including 17 questions collecting quantitative and qualitative data. Thirty-six medical centres from 14 European countries responded and 30 out of 36 centres were reference centres of the European Reference Network on Rare Endocrine Conditions, EndoERN.

RESULTS

Pdex treatment is currently provided by 36% of the surveyed centres. The treatment is initiated by different specialties, that is paediatricians, endocrinologists, gynaecologists or geneticists. Regarding the starting point of Pdex, 23% stated to initiate therapy at 4-5 weeks postconception (wpc), 31% at 6 wpc and 46 % as early as pregnancy is confirmed and before 7 wpc at the latest. A dose of 20 µg/kg/day is used. Dose distribution among the centres varies from once to thrice daily. Prenatal diagnostics for treated cases are conducted in 72% of the responding centres. Cases treated per country and year vary between 0.5 and 8.25. Registries for long-term follow-up are only available at 46% of the centres that are using Pdex treatment. National registries are only available in Sweden and France.

CONCLUSIONS

This study reveals a high international variability and discrepancy in the use of Pdex treatment across Europe. It highlights the importance of a European cooperation initiative for a joint international prospective trial to establish evidence-based guidelines on prenatal diagnostics, treatment and follow-up of pregnancies at risk for CAH.

Fetal Hand Abnormalities in the First-Trimester Scan: A Report of Two Cases

Two cases of fetal hand abnormalities are presented in this report. The first one is a case of unilateral fetal syndactyly detected in the first trimester routine scan, resulting in the early diagnosis of a severe genetic condition by invasive testing and early termination of pregnancy. By doing so, we ensured that the woman was managed in the most appropriate way. In the second case, we describe a fetus with bilateral hand polydactyly, which was combined with a cardiac defect - incompatible with extrauterine life. This was once again diagnosed during the first trimester scan. An uncomplicated termination of pregnancy was achieved in the first trimester of pregnancy.

Amniotic Fluid: A Perspective on Promising Advances in the Prevention and Treatment of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a common and potentially fatal disease that typically affects preterm (PIs) and very low birth weight infants (VLBWIs). Although NEC has been extensively studied, the current therapeutic approaches are unsatisfactory. Due to the similarities in the composition between human amniotic fluid (AF) and human breast milk (BM), which plays a protective role in the development of NEC in PIs and VLBWIs, it has been postulated that AF has similar effects on the outcome of NEC and potential therapeutic implications. AF has been long used for its diagnostic purposes and is often discarded after birth as "biological waste". However, researchers have started to elucidate its therapeutic potential. Experimental studies in animal models have shown that diseases of various organ systems can possibly benefit from AF-based therapy. Hence, we have identified three approaches which show promising results for future clinical application in the prevention and/or treatment of NEC: (1) administration of processed AF (PAF) isolated from donor mothers, (2) administration of AF stem cells (AFSCs), and (3) administration of simulated AF (SAF) formulated to mimic the composition of physiological AF. We have highlighted the most important aspects that should be taken into account to guide further research on the clinical application of AF-based therapy. We hope that this review can provide a framework to identify the challenges of AF-based therapy and help to design future studies to better evaluate AF-based approaches for the treatment and/or prevention of NEC in PIs and VLBWIs.

Absolute Risk of Adverse Obstetric Outcomes Among Twin Pregnancies After In Vitro Fertilization by Maternal Age

IMPORTANCE

Twin pregnancy is a common occurrence in pregnancies conceived with in vitro fertilization (IVF), but the absolute risk of adverse obstetric outcomes stratified by IVF, twin or singleton pregnancy, and maternal age are unknown.

OBJECTIVE

To estimate the absolute risk of adverse obstetric outcomes at each maternal age among twin pregnancies conceived with IVF.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included pregnant women with infants born from January 1, 2013, to December 31, 2018, based on the Hospital Quality Monitoring System in China. Data were analyzed from September 1, 2020, to June 30, 2021.

EXPOSURES

Twin pregnancy with IVF (IVF-T), singleton pregnancy with IVF (IVF-S), twin pregnancy with non-IVF (nIVF-T), and singleton pregnancy with non-IVF (nIVF-S).

MAIN OUTCOMES AND MEASURES

Sixteen obstetric outcomes, including 10 maternal complications (gestational hypertension, eclampsia and preeclampsia, gestational diabetes, placenta previa, placental abruption, placenta accreta, preterm birth, dystocia, cesarean delivery, and postpartum hemorrhage) and 6 neonatal complications (fetal growth restriction, low birth weight, very low birth weight, macrosomia, malformation, and stillbirth).

RESULTS

Among 16 879 728 pregnant women aged 20 to 49 years (mean [SD] age, 29.2 [4.7] years), the twin-pregnancy rates were 32.1% in the IVF group and 1.5% in the non-IVF group (relative risk, 20.8; 95% CI, 20.6-20.9). The most common adverse obstetric outcomes after pregnancy conceived with IVF were cesarean delivery (88.8%), low birth weight (43.8%), preterm birth (39.6%), gestational diabetes (20.5%), gestational hypertension and preeclampsia and eclampsia (17.5%), dystocia (16.8%), and postpartum hemorrhage (11.9%). The absolute risk of most adverse obstetric outcomes in each subgroup presented in 2 dominant patterns: Pattern A indicated the absolute risk ranging from IVF-T to nIVF-T to IVF-S to nIVF-S, and pattern B indicated the absolute risk ranging from IVF-T to IVF-S to nIVF-T to nIVF-S. Both patterns showed an elevated obstetric risk with increasing maternal age in each subgroup.

CONCLUSIONS AND RELEVANCE

In this cohort study, twin pregnancy, IVF, and advanced maternal age were independently associated with adverse obstetric outcomes. Given these findings, promotion of the elective single embryo transfer strategy is needed to reduce multiple pregnancies following IVF technologies. Unnecessary cesarean delivery shouldh be avoided in all pregnant women.

European principles of care for women and girls with inherited bleeding disorders

INTRODUCTION

Despite increasing awareness of issues faced by women and girls with inherited BDs (WGBD), standards of care are lacking, with disparities in diagnosis and treatment for WGBD across Europe. We aimed to develop practical principles of care (PoC) to promote standardization of care for WGBD within European Haemophilia Treatment and Comprehensive Care Centres (HTC/CCCs).

METHODS

The co-creation process, supported by the European Association for Haemophilia and Allied Disorders, consisted of four multidisciplinary meetings with health care providers (HCPs) experienced in WGBD care, and European Haemophilia Consortium representatives, combined with broad patient and HCP consultations in the European haemophilia community. Relevant medical societies outside Europe were contacted for confirmation.

RESULTS

We developed ten PoC for WGBD, stressing the importance and benefits of a centralized, multidisciplinary, comprehensive, family-centred approach to support and manage WGBD during all life stages. These PoC emphasise the right to equitable access and quality of care for all people with BDs, irrespective of gender. Multiple medical societies outside Europe also confirmed their support for endorsement.

CONCLUSIONS

Ten PoC for WGBD evolved from an iterative process among stakeholders, supported by relevant medical societies worldwide. These PoC can serve as a benchmark for diagnosis and comprehensive multidisciplinary management of WGBD, and improve awareness of their unique challenges. They offer a framework to guide HTC/CCCs in providing equitable care for all WGBD, both in their own services and in other healthcare settings. Implementation of these principles aims to positively impact the health, wellbeing and quality of life for WGBD.

Fetal Genetic Diagnosis by Chorionic Villus Sampling: Evaluation of the Five-Year Experience from a Single Center

We summarized our five-year chorionic villus sampling (CVS) experience with indications, detected chromosomal abnormalities and pregnancy outcomes. Materials and Methods: This retrospective study examined 552 patients underwent CVS for prenatal diagnosis between 2014 and 2018. Results: The most frequent patients undergoing CVS indications were abnormal aneuploidy screening results, increased nuchal translucency, and cystic hygroma/edema. Of 552 CVS, 385 were normal, 141 abnormal. Eight were contaminated with maternal cells, 4 were mosaics, in 12 the culture failed, and in 2 there was inadequate sampling. The most frequent chromosomal abnormalities were trisomy 21, trisomy 18 and 45,X. Of 246 followed pregnancies, there were 165 live-births (67,1%), 58 pregnancy terminations (23,6%), and 23 pregnancy losses (9,3%). There were 5 procedure-related losses (2%), 3 of which were chromosomally normal. Conclusion: Although significant advances have been made in noninvasive methods such as NIPT, CVS is still a reliable technique for cytogenetic diagnosis in early gestation.

Evaluation of the Fetal Therapy Evidence in Lower Urinary Tract Obstruction: Would an ERAS Guideline Improve Outcomes?

BACKGROUND

Pregnancies that are prenatally identified to have fetal anomalies are complex and require expert multidisciplinary care. As many conditions can impact the fetus prenatally and require intervention, an enhanced recovery after surgery (ERAS) for lower urinary tract obstruction (LUTO) is being evaluated to determine the level of evidenced-based data available.

PROBLEM

The percutaneous ultrasound-guided fetal surgery procedure for bladder neck obstruction is the focus for elements of preoperative counseling, intraoperative procedure/risk complications, and postoperative management.

METHODS

A quality improvement review Squire 2.0 (2000-2020) was undertaken for the percutaneous LUTO fetal surgery shunting (lower urinary tract obstruction), process and procedure which require 2 process pathways, one to evaluate the fetal candidate and a second to treat. This structured review is focused on identifying the process elements to allow the determination of the number of evidenced-based elements that would allow for audit and measurement of the clinical element variance for comparative feedback to the individual surgical provider or surgery center.

INTERVENTIONS

Titles and abstracts were screened to identify potentially relevant articles with priority given to meta-analyses, systematic reviews, randomized controlled studies, nonrandomized controlled studies, reviews, and case series.

RESULTS

A series of potential clinical elements for the diagnostic fetal evaluation and for the 3 protocol areas of surgical care for the procedures (pre-, intra-, and postoperative care) are identified using an ERAS-like process.

CONCLUSIONS

The identified clinical elements have the potential for ERAS-LUTO fetal therapy guideline. Multidisciplinary collaboration (surgeon, anesthesia, nursing, imaging, and laboratory) is required for ERAS quality improvement in the pre-, intra-, and postoperative processes. Process elements in each of the operative areas can be audited, evaluated, compared, and modified/improved.

Novel Approaches to Develop Critical Reference Materials for Noninvasive Prenatal Testing: A Pilot Study

BACKGROUND

Highly characterized reference materials are required to expand noninvasive prenatal testing (NIPT) for low incidence aneuploidies and microdeletions. The goal of this study was to develop reference materials for the development of next generation circulating cell-free DNA (ccfDNA) assays.

METHODS

This was a prospective study of pregnancies complicated by positive prenatal genetic screening. ccfDNA was isolated from maternal plasma and amplified. Lymphoblastoid cell lines were prepared from maternal peripheral blood mononuclear cells and fetal cord blood cells. Cells were Epstein-Barr virus immortalized and expanded. Amplified DNA and to a limited extent formulated lymphoblastoid-derived ccfDNA was tested in SNP-based and chromosome counting (CC) based massively parallel sequencing assays.

RESULTS

Enrolled cases included fetuses with: T21 (2), T18 (1), T18-XXX (1), XYY (1), microdeletions (1), and euploid (2). Three lymphoblastoid cells lines were prepared. Genomic DNA was extracted from cell lines and fragmented to simulate ccfDNA. ccfDNA isolation yielded about 2000 usable genome equivalents of DNA for each case for amplification. Although the sonicated genomic DNA derived from lymphoblastoid cell lines did not yield results compatible with NIPT assays, when blinded, NIPT platforms correctly identified the amplified ccfDNA isolated from blood in the majority of cases.

CONCLUSIONS

This study showed that maternal blood samples from pregnancies complicated by common chromosomal abnormalities can be used to generate materials for the development and evaluation of NIPT assays.

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.

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.

Genetic testing for unexplained perinatal disorders

PURPOSE OF REVIEW

Perinatal disorders include stillbirth, congenital structural anomalies, and critical illnesses in neonates. The cause of these is often unknown despite a thorough clinical workup. Genetic diseases cause a significant portion of perinatal disorders. The purpose of this review is to describe recent advances in genetic testing of perinatal disorders of unknown cause and to provide a potential diagnostic strategy.

RECENT FINDINGS

Exome and genome sequencing (ES and GS) have demonstrated that significant portions of perinatal disorders are caused by genetic disease. However, estimates of the exact proportion have varied widely across fetal and neonatal cohorts and most of the genetic diagnoses found in recent studies have been unique to individual cases. Having a specific genetic diagnosis provides significant clinical utility, including improved prognostication of the outcome, tailored therapy, directed testing for associated syndromic manifestations, referral to appropriate subspecialists, family planning, and redirection of care.

SUMMARY

Perinatal disorders of unknown cause, with nonspecific presentations, are often caused by genetic diseases best diagnosed by ES or GS. Prompt diagnosis facilitates improved clinical care. Improvements in noninvasive sampling, variant interpretation, and population-level research will further enhance the clinical utility of genetic testing.

VIDEO ABSTRACT

http://links.lww.com/MOP/A61.

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.

A Rapid PCR-Free Next-Generation Sequencing Method for the Detection of Copy Number Variations in Prenatal Samples

Next-generation sequencing (NGS) is emerging as a new method for the detection of clinically significant copy number variants (CNVs). In this study, we developed and validated rapid CNV-sequencing (rCNV-seq) for clinical application in prenatal diagnosis. Low-pass whole-genome sequencing was performed on PCR libraries prepared from amniocyte genomic DNA. From 10-40 ng of input DNA, PCR-free libraries consistently produced sequencing data with high unique read mapping ratios, low read redundancy, low coefficient of variation for all chromosomes and high genomic coverage. In validation studies, reliable and accurate CNV detection using PCR-free-based rCNV-seq was demonstrated for a range of common trisomies and sex chromosome aneuploidies as well as microdeletion and duplication syndromes. In reproducibility studies, CNV copy number and genomic intervals closely matched those defined by chromosome microarray analysis. Clinical testing of genomic DNA samples from 217 women referred for prenatal diagnosis identified eight samples (3.7%) with known chromosome disorders. We conclude that PCR-free-based rCNV-seq is a sensitive, specific, reproducible and efficient method that can be used in any NGS-based diagnostic laboratory for detection of clinically significant CNVs.

Clinical Practice Guidelines for Prenatal Aneuploidy Screening and Diagnostic Testing from Korean Society of Maternal-Fetal Medicine: (2) Invasive Diagnostic Testing for Fetal Chromosomal Abnormalities

The Korean Society of Maternal Fetal Medicine proposed the first Korean guideline on prenatal aneuploidy screening and diagnostic testing, in April 2019. The clinical practice guideline (CPG) was developed for Korean women using an adaptation process based on good-quality practice guidelines, previously developed in other countries, on prenatal screening and invasive diagnostic testing for fetal chromosome abnormalities. We reviewed current guidelines and developed a Korean CPG on invasive diagnostic testing for fetal chromosome abnormalities according to the adaptation process. Recommendations for selected 11 key questions are: 1) Considering the increased risk of fetal loss in invasive prenatal diagnostic testing for fetal genetic disorders, it is not recommended for all pregnant women aged over 35 years. 2) Because early amniocentesis performed before 14 weeks of pregnancy increases the risk of fetal loss and malformation, chorionic villus sampling (CVS) is recommended for pregnant women who will undergo invasive prenatal diagnostic testing for fetal genetic disorders in the first trimester of pregnancy. However, CVS before 9 weeks of pregnancy also increases the risk of fetal loss and deformity. Thus, CVS is recommended after 9 weeks of pregnancy. 3) Amniocentesis is recommended to distinguish true fetal mosaicism from confined placental mosaicism. 4) Anti-immunoglobulin should be administered within 72 hours after the invasive diagnostic testing. 5) Since there is a high risk of vertical transmission, an invasive prenatal diagnostic testing is recommended according to the clinician's discretion with consideration of the condition of the pregnant woman. 6) The use of antibiotics is not recommended before or after an invasive diagnostic testing. 7) The chromosomal microarray test as an alternative to the conventional cytogenetic test is not recommended for all pregnant women who will undergo an invasive diagnostic testing. 8) Amniocentesis before 14 weeks of gestation is not recommended because it increases the risk of fetal loss and malformation. 9) CVS before 9 weeks of gestation is not recommended because it increases the risk of fetal loss and malformation. 10) Although the risk of fetal loss associated with invasive prenatal diagnostic testing (amniocentesis and CVS) may vary based on the proficiency of the operator, the risk of fetal loss due to invasive prenatal diagnostic testing is higher in twin pregnancies than in singleton pregnancies. 11) When a monochorionic twin is identified in early pregnancy and the growth and structure of both fetuses are consistent, an invasive prenatal diagnostic testing can be performed on one fetus alone. However, an invasive prenatal diagnostic testing is recommended for each fetus in cases of pregnancy conceived via in vitro fertilization, or in cases in which the growth of both fetuses differs, or in those in which at least one fetus has a structural abnormality. The guidelines were established and approved by the Korean Academy of Medical Sciences. This guideline is revised and presented every 5 years.

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.

Non-Invasive Prenatal Testing: Current Perspectives and Future Challenges

Fetal aneuploidies are among the most common causes of miscarriages, perinatal mortality and neurodevelopmental impairment. During the last 70 years, many efforts have been made in order to improve prenatal diagnosis and prenatal screening of these conditions. Recently, the use of cell-free fetal DNA (cff-DNA) testing has been increasingly used in different countries, representing an opportunity for non-invasive prenatal screening of pregnant women. The aim of this narrative review is to describe the state of the art and the main strengths and limitations of this test for prenatal screening of fetal aneuploidies.

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.

Pre-analytical Practices in the Molecular Diagnostic Tests, A Concise Review

Molecular assays for detection of nucleic acids in biologic specimens are valuable diagnostic tools supporting clinical diagnoses and therapeutic decisions. Pre-analytical errors, which occur before or during processing of nucleic acid extraction, contribute a significant role in common errors that take place in molecular laboratories. Certain practices in specimen collection, transportation, and storage can affect the integrity of nucleic acids before analysis. Applying best practices in these steps, helps to minimize those errors and leads to better decisions in patient diagnosis and treatment. Widely acceptable recommendations, which are for optimal molecular assays associated with pre-analytic variables, are limited. In this article, we have reviewed most of the important issues in sample handling from bed to bench before starting molecular tests, which can be used in diagnostic as well as research laboratories. We have addressed the most important pre-analytical points in performing molecular analysis in fixed and unfixed solid tissues, whole blood, serum, plasma, as well as most of the body fluids including urine, fecal and bronchial samples, as well as prenatal diagnosis samples.

New approach for estimating risk of miscarriage after chorionic villus sampling

OBJECTIVE

To estimate the risk of miscarriage associated with chorionic villus sampling (CVS).

METHODS

This was a retrospective cohort study of women attending for routine ultrasound examination at 11 + 0 to 13 + 6 weeks' gestation at one of eight fetal-medicine units in Spain, Belgium and Bulgaria, between July 2007 and June 2018. Two populations were included: (1) all singleton pregnancies undergoing first-trimester assessment at Hospital Clínico Universitario Virgen de la Arrixaca in Murcia, Spain, that did not have CVS (non-CVS group); and (2) all singleton pregnancies that underwent CVS following first-trimester assessment at one of the eight participating centers (CVS group). We excluded pregnancies diagnosed with genetic anomalies or major fetal defects before or after birth, those that resulted in termination and those that underwent amniocentesis later in pregnancy. We used propensity score (PS) matching analysis to estimate the association between CVS and miscarriage. We compared the risk of miscarriage of the CVS and non-CVS groups after PS matching (1:1 ratio). This procedure creates two comparable groups balancing the maternal and pregnancy characteristics that are associated with CVS, in a similar way to that in which randomization operates in a randomized clinical trial.

RESULTS

The study population consisted of 22 250 pregnancies in the non-CVS group and 3613 in the CVS group. The incidence of miscarriage in the CVS group (2.1%; 77/3613) was significantly higher than that in the non-CVS group (0.9% (207/22 250); P < 0.0001). The PS algorithm matched 2122 CVS with 2122 non-CVS cases, of which 40 (1.9%) and 55 (2.6%) pregnancies in the CVS and non-CVS groups, respectively, resulted in a miscarriage (odds ratio (OR), 0.72 (95% CI, 0.48-1.10); P = 0.146). We found a significant interaction between the risk of miscarriage following CVS and the risk of aneuploidy, suggesting that the effect of CVS on the risk of miscarriage differs depending on background characteristics. Specifically, when the risk of aneuploidy is low, the risk of miscarriage after CVS increases (OR, 2.87 (95% CI, 1.13-7.30)) and when the aneuploidy risk is high, the risk of miscarriage after CVS is paradoxically reduced (OR, 0.47 (95% CI, 0.28-0.76)), presumably owing to prenatal diagnosis and termination of pregnancies with major aneuploidies that would otherwise have resulted in spontaneous miscarriage. For example, in a patient in whom the risk of aneuploidy is 1 in 1000 (0.1%), the risk of miscarriage after CVS will increase to 0.3% (0.2 percentage points higher).

CONCLUSIONS

The risk of miscarriage in women undergoing CVS is about 1% higher than that in women who do not have CVS, although this excess risk is not solely attributed to the invasive procedure but, to some extent, to the demographic and pregnancy characteristics of the patients. After accounting for these risk factors and confining the analysis to low-risk pregnancies, CVS seems to increase the risk of miscarriage by about three times above the patient's background risk. Although this is a substantial increase in relative terms, in pregnancies without risk factors for miscarriage, the risk of miscarriage after CVS remains low and similar to, or slightly higher than, that in the general population. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Preimplantation Genetic Testing for Monogenic Kidney Disease

BACKGROUND AND OBJECTIVES

A genetic cause can be identified for an increasing number of pediatric and adult-onset kidney diseases. Preimplantation genetic testing (formerly known as preimplantation genetic diagnostics) is a reproductive technology that helps prospective parents to prevent passing on (a) disease-causing mutation(s) to their offspring. Here, we provide a clinical overview of 25 years of preimplantation genetic testing for monogenic kidney disease in The Netherlands.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This is a retrospective cohort study of couples counseled on preimplantation genetic testing for monogenic kidney disease in the national preimplantation genetic testing expert center (Maastricht University Medical Center+) from January 1995 to June 2019. Statistical analysis was performed through chi-squared tests.

RESULTS

In total, 98 couples were counseled regarding preimplantation genetic testing, of whom 53% opted for preimplantation genetic testing. The most frequent indications for referral were autosomal dominant polycystic kidney disease (38%), Alport syndrome (26%), and autosomal recessive polycystic kidney disease (9%). Of couples with at least one preimplantation genetic testing cycle with oocyte retrieval, 65% experienced one or more live births of an unaffected child. Of couples counseled, 38% declined preimplantation genetic testing for various personal and technical reasons.

CONCLUSIONS

Referrals, including for adult-onset disease, have increased steadily over the past decade. Though some couples decline preimplantation genetic testing, in the couples who proceed with at least one preimplantation genetic testing cycle, almost two thirds experienced at least one live birth rate.

Molecular Diagnostics and In Utero Therapeutics for Orofacial Clefts

Orofacial clefts and their management impose a substantial burden on patients, on their families, and on the health system. Under the current standard of care, affected patients are subjected to a lifelong journey of corrective surgeries and multidisciplinary management to replace bone and soft tissues, as well as restore esthetics and physiologic functions while restoring self-esteem and psychological health. Hence, a better understanding of the dynamic interplay of molecular signaling pathways at critical phases of palate development is necessary to pioneer novel prenatal interventions. Such pathways include transforming growth factor-β (Tgfβ), sonic hedgehog (Shh), wingless-integrated site (Wnt)/β-catenin, bone morphogenetic protein (Bmp), and fibroblast growth factor (Fgf) and its associated receptors, among others. Here, we summarize commonly used surgical methods used to correct cleft defects postnatally. We also review the advances made in prenatal diagnostics of clefts through imaging and genomics and the various in utero surgical corrections that have been attempted thus far. An overview of how key mediators of signaling that drive palatogenesis are emphasized in the context of the framework and rationale for the development and testing of therapeutics in animal model systems and in humans is provided. The pros and cons of in utero therapies that can potentially restore molecular homeostasis needed for the proper growth and fusion of palatal shelves are presented. The theme advanced throughout this review is the need to develop preclinical molecular therapies that could ultimately be translated into human trials that can correct orofacial clefts at earlier stages of development.

Acute Perinatal Infection and the Evidenced-Based Risk of Intrauterine Diagnostic Testing: A Structured Review

BACKGROUND

The prevalence of perinatal infection from maternal exposure is increasing. The prevalence of acute maternal infections identifies cytomegalovirus, parvovirus B19, toxoplasmosis, and varicella as the most common organisms and in the order of frequency. Maternal informed consent and understanding is required before intrauterine testing for fetal infectious and possible genetic risk assessment.

METHODS

This structured review of the reproductive published literature focuses on the risks of amniocentesis and cordocentesis diagnostic procedure-related fetal loss rates and fetal vertical transmission (VT) rates from published infected pregnant cohorts.

RESULTS

The total postprocedure fetal loss rate for diagnostic amniocentesis procedures, in limited infectious cohorts, is 1.5% and does not appear to be increased compared to "noninfected" amniocentesis cohorts using an estimated background spontaneous fetal loss rate (no procedure) of 0.65%. The "pooled" unintended fetal loss rate is from small infected population cohorts, but can be used for counseling purposes. Postcordocentesis fetal loss risk, in an infected cohort, is not possible to estimate due to limited data. The "biological spontaneous fetal loss rate" risk with a perinatal infection (positive or negative fetal anomalies) and no diagnostic procedure before 20 weeks of gestation is reviewed. The risk of VT in acute infection cohorts as a result of the intra-amniotic diagnostic procedure is not found to be increased.

CONCLUSION

The unintended "fetal loss" rate after amniocentesis for perinatal infected cohorts is similar to that of noninfected cohorts, but the estimate is based on limited infected cohorts. There was no procedure-based risk of fetal VT in the infected cohorts, but identification of postprocedure maternal bleeding into the amniotic cavity increases the potential risk. Maternal knowledge translation and an informed consent process with risk-benefit maternal/fetal risk counseling are required prior to any diagnostic amniocentesis procedure.

Stimuli-Responsive Microfluidic Interface Enables Highly Efficient Capture and Release of Circulating Fetal Cells for Non-Invasive Prenatal Testing

Circulating fetal nucleated cells (CFCs) carrying whole genomic coding of the fetus in maternal blood have been pursued as ideal biomarkers for noninvasive prenatal testing (NIPT). However, a significant limitation is the need to enrich sufficient cells in quantity and purity for fetal genetic disorder diagnosis. This study for the first time demonstrates a stimuli-responsive ligand enabling interface on array patterned microfluidic chip (NIPT-Chip) for high efficient isolation and release of CFCs in untreated whole blood. Deterministic lateral displacement (DLD)-array was patterned in the chip to increase collision frequency between CFCs and surface-anchored antibody to achieve high efficient cell capture. More importantly, the stimuli-responsive interface enables gentle release of captured CFCs through a thiol exchange reaction for downstream gene analysis of NIPT. With the advantages of simple processing, efficient isolation, and gentle release, NIPT-Chip offers great potential for clinical translation of circulating fetal cell-based NIPT.

Reproductive options for families at risk of Osteogenesis Imperfecta: a review

Background

Osteogenesis Imperfecta (OI) is a rare genetic disorder involving bone fragility. OI patients typically suffer from numerous fractures, skeletal deformities, shortness of stature and hearing loss. The disorder is characterised by genetic and clinical heterogeneity. Pathogenic variants in more than 20 different genes can lead to OI, and phenotypes can range from mild to lethal forms. As a genetic disorder which undoubtedly affects quality of life, OI significantly alters the reproductive confidence of families at risk. The current review describes a selection of the latest reproductive approaches which may be suitable for prospective parents faced with a risk of OI. The aim of the review is to alleviate suffering in relation to family planning around OI, by enabling prospective parents to make informed and independent decisions.

Main body

The current review provides a comprehensive overview of possible reproductive options for people with OI and for unaffected carriers of OI pathogenic genetic variants. The review considers reproductive options across all phases of family planning, including pre-pregnancy, fertilisation, pregnancy, and post-pregnancy. Special attention is given to the more modern techniques of assisted reproduction, such as preconception carrier screening, preimplantation genetic testing for monogenic diseases and non-invasive prenatal testing. The review outlines the methodologies of the different reproductive approaches available to OI families and highlights their advantages and disadvantages. These are presented as a decision tree, which takes into account the autosomal dominant and autosomal recessive nature of the OI variants, and the OI-related risks of people without OI.

The complex process of decision-making around OI reproductive options is also discussed from an ethical perspective.

Conclusion

The rapid development of molecular techniques has led to the availability of a wide variety of reproductive options for prospective parents faced with a risk of OI. However, such options may raise ethical concerns in terms of methodologies, choice management and good clinical practice in reproductive care, which are yet to be fully addressed.

Sex selection and non-invasive prenatal testing: A review of current practices, evidence, and ethical issues

Non-invasive prenatal testing (NIPT) can determine the sex of the fetus very accurately and very early in gestation. There are concerns that the ease, timing, and accuracy of NIPT sex determination will facilitate sex-selective termination of pregnancy (TOP). Here, we review current practices, the evidence for a link between NIPT and sex-selective TOP, and associated ethical issues. Sex-selective TOP, usually motivated by son preference, has had serious demographic consequences in countries such as India and China. Currently, ultrasound is the primary method by which parents determine the sex of the fetus. The diffusion of ultrasound technology has had a direct impact on the rates of sex-selective TOP. Although NIPT is currently more costly, it is feasible that increased uptake of this technology could have a similar effect. Partly because NIPT is a relatively recent development in prenatal screening, there is little data on the impact of NIPT on sex selection practices. Evidence that NIPT is playing a role in sex-selective TOP remains largely anecdotal. Further research is required to assess and quantify TOP resulting from NIPT sex determination. The use of these technologies for sex selection raises a number of ethical issues, in addition to practical demographic consequences.

Chromosomal microarray analysis for the detection of chromosome abnormalities in fetuses with echogenic intracardiac focus in women without high-risk factors

To investigate the association between pathogenic copy number variants (p-CNVs) and abnormal karyotypes detected by chromosomal microarray analysis (CMA) and echogenic intracardiac focus (EIF).This was a retrospective study of fetuses with EIF with CMA data at the Prenatal Diagnosis Center of the West China Second University Hospital of Sichuan University between September 2014 and May 2017. Fetuses were assigned to the isolated EIF and non-isolated EIF groups according to the presence of other ultrasound abnormalities.Among 244 pregnant women, there were 143 cases of isolated EIF and 101 of non-isolated EIF. CMA revealed chromosome abnormality (n = 9 (3.7%): trisomy 21, n = 4; sexual trisomy, n = 2; and p-CNV, n = 3), variants of unknown significance (VOUS, n = 19), and benign CNV (b-CNV, n = 216). Among the fetuses with isolated EIF, 5 had chromosomal abnormalities (3.5%). Among the fetuses with non-isolated EIF, four had chromosomal abnormalities (4.0%). All fetuses with trisomy 21 were in the non-isolated group. The frequency of labor induction was 66.7% (6/9) among the fetuses with chromosome abnormality and 21.1% (4/19) among those with VOUS. Among those with chromosomal abnormalities, one (11.1%) had congenital heart disease.In pregnant women without high-risk factors for chromosomal abnormalities, ultrasound abnormalities, including EIF, could be an indication for CMA. Ultrasound abnormalities (including EIF) and chromosome abnormality could indicate a high risk of CHD. The presence of EIF and at least another ultrasound abnormality could indicate a high risk of trisomy 21.

Procedure related risk of premature delivery and fetal growth reduction following amniocentesis, transcervical and transabdominal chorionic villus sampling: a retrospective study

Background The aim of this study was to compare transabdominal and transcervical chorionic villus sampling (CVS) as well as amniocentesis (AC) with respect to their rates of premature delivery and fetal growth restriction. Methods We retrospectively evaluated the mentioned procedures of invasive prenatal testing performed in a single center between 2001 and 2016. Seven hundred and ninety-nine cases of AC and 719 cases of CVS were included, of which 400 were performed transvaginally. Only singleton pregnancies with a normal karyotype and delivery after 24 + 0 weeks of gestation were included. Fetal growth restriction was defined as birth weight below the 10th percentile. Premature delivery was defined as delivery before 37 + 0 weeks of gestation. Data were compared to a control group without an invasive procedure. Results The frequency of premature delivery was 8.5% after transabdominal CVS, 6.3% after transcervical CVS and 10.5% after AC as compared to 10.8% in the control group. The frequency of fetal growth restriction was 8.2% after transabdominal CVS 6.8% after transcervical CVS and 8.4% after AC as compared to 9.7% in the control group. Conclusion Our study supports that the three different methods of invasive prenatal testing do not lead to a higher risk of either premature delivery or fetal growth restriction when compared to controls. We found no difference in risk profile among the three techniques.