ISUOG Practice Guidelines: invasive procedures for prenatal diagnosis

Pregnancy and childbirth in patients with Glanzmann Thrombasthenia

Glanzmann thrombasthenia (GT) is a rare inherited platelet bleeding disorder caused by a quantitative and/or qualitative defect of the αIIbβ3 integrin. Pregnancy and delivery pose special challenges as they entail increased risks of both maternal and foetal bleeding that may be life-threatening. Multidisciplinary management throughout the preconception, intrapartum and peripartum periods is vital to optimize pregnancy outcomes. This Nutshell review focuses on the challenging management of pregnancy and childbirth in patients with GT.

Cumulative sum learning curve for cordocentesis among maternal-fetal medicine fellows in a low-cost simulation model

OBJECTIVE

To determine the individual learning curves for cordocentesis in a low-cost simulator for maternal-fetal medicine (MFM) fellows.

METHODS

This observational, descriptive, educational, and prospective study was performed from July through November 2022. After an introductory course based on a standardized technique for cordocentesis, each second-year MFM fellow who accepted to participate in the study performed this procedure using a low-cost simulation model, and experienced operators supervised the cordocenteses. Learning curves were then created using cumulative sum analysis (CUSUM).

RESULTS

Seven second-year MFM fellows with no previous experience in cordocentesis accepted to participate in the study. A total of 2676 procedures were assessed. On average, residents performed 382 ± 70 procedures. The mean number of procedures to achieve proficiency was 369 ± 70, the overall success rate was 84.16%, and the corresponding failure rate was 15.84%. At the end of the study, all fellows were considered competent in cordocentesis. One fellow required 466 attempts to achieve competency, performing a total of 478 procedures, but the resident with the fewest attempts to reach competency required 219 procedures, completing 232 procedures. Some of the most frequent reasons for failed attempts included not reaching the indicated point for vascular access (20.99%) and being unable to retrieve the sample (69.10%).

CONCLUSION

CUSUM analysis to assess learning curves, in addition to using low-cost simulation models, helped to appraise individualized learning, allowing an objective demonstration of competency for cordocentesis among MFM fellows.

Placental Cannabinoid Receptor Expression in Preterm Birth

Background: The cannabinoid receptor (CBR) plays a significant role in oogenesis, pregnancy, and childbirth. It might also play a significant role in preterm birth (PTB). The aim of the study was to investigate the association between the expression of the CBR in the placenta and the incidence of PTB. Methods: This prospective, observational, multicentre preliminary study was conducted on placental samples obtained from 109 women. The study included 95 patients hospitalized due to the high risk of PTB. They were divided into two groups: Group 1, where the expression of the CBR1 and CBR1a was analyzed, and Group 2, in which we examined CBR2 expression. The control group, that is, Group 3, consisted of 14 women who delivered at term, and their placentas were tested for the presence of all three receptor types (CBR1, CBR1a, and CBR2). Results: The study used reverse transcription and real-time PCR methods to assess the expression of CBRs in the placental tissues. The expression of the CBR2, CBR1, and CBR1a receptors was significantly lower in the placentas of women after PTB compared to those after term births, p = 0.038, 0.033, and 0.034, respectively. Conclusions: The presence of CBR mRNA in the human placental tissue was confirmed. The decreased expression of CBRs could serve as an indicator in predicting PTB.

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.

Limited additional value of karyotyping cultured amniotic fluid cell colonies in addition to microarray on uncultured cells for confirmation of abnormal non-invasive prenatal testing results

OBJECTIVES

Non-invasive prenatal testing (NIPT) allows the detection of placental chromosome aberrations. To verify whether the fetus also has the chromosome aberration, diagnostic follow-up testing is required. The aim of this retrospective study was to assess the added value of analyzing amniotic fluid (AF) cell cultures in addition to uncultured AF cells for the detection of fetal mosaicism.

METHOD

NIPT was performed as part of the Dutch TRIDENT study. Cytogenetic studies in uncultured AF were performed using single nucleotide polymorphism (SNP)-array. Cultured AF cell colonies (in situ method) were investigated with fluorescent in situ hybridization and/or karyotyping. Clinical outcome data were collected in cases with discordant results.

RESULTS

Between April 2014 and December 2021, 368 amniocenteses were performed after a chromosomal aberration was detected with NIPT. Excluding 134 cases of common aneuploidies (confirmed by quantitative fluorescence polymerase chain reaction), 29 cases with investigation of uncultured cells only and 1 case without informed consent, 204 cases were eligible for this study. In 196 (96%) cases, the results in uncultured and cultured cells were concordant normal, abnormal or mosaic. Five cases (2%) showed mosaicism in cultured AF cells, whereas uncultured AF cells were normal. Two (1%) of these, one mosaic trisomy 13 and one mosaic trisomy 16, were considered true fetal mosaics.

CONCLUSION

The added value of investigating AF cell cultures in addition to uncultured cells is limited to two of 204 (1%) cases in which true fetal mosaicsm would otherwise be missed. The clinical relevance of one (trisomy 13) remained unknown and the other case also showed ultrasound anomalies, which determined pregnancy management. This seems to justify limiting prenatal cytogenetic confirmatory testing to SNP arrays on uncultured AF cells, considerably shortening the reporting time.

Challenges of prenatal diagnosis in obese pregnant women

Obesity rates are increasing world-wide with most of the increase in women of the reproductive age group. While recognised as an important contributor to non-communicable diseases, pregnant women with obesity are particularly at risk of not only maternal and pregnant complications but also have an increased risk of congenital malformations. Furthermore, pregnant obese women are more likely to be older and therefore at a greater risk of aneuploidy. Prenatal diagnosis in these women especially those who are morbidly obese is challenging due not only to their weight but the implications of the increase adiposity on biochemical markers of aneuploidy. In this review we discuss the current challenges in providing prenatal diagnosis for these women including those related to the ergonomics of ultrasound and those inherent in them because of their obesity. Appropriate counselling for these women should include the lower sensitivity of the tests, the difficulties in performing some of the procedures (imaging and invasive testing) as well as the increased risk of structural abnormalities related to their obesity.

Developmental Process and Symmetry of Fetal Sulci in the Mesial Area Assessed by Ultrasound: A Cohort Study in Chinese Population

OBJECTIVE

We aimed to investigate the progression of cortical development in Chinese population and to determine the rate of isolated asymmetric cortical development. We also explored the outcomes of these fetuses and determined whether cortical asymmetry represents normal individual physiological variation.

METHODS

Our observational cohort study included 456 healthy singleton pregnant women who visited Peking University First Hospital between September 2020 and December 2021. We evaluated the progression and symmetry of the parieto-occipital sulcus, calcarine sulcus, and cingulate sulcus using a scoring system during routine fetal ultrasound examinations. The outcomes of the included fetuses after birth were assessed using the Ages and Stages Questionnaire, Third Edition (ASQ-3).

RESULTS

The median gestational ages at which the parieto-occipital, calcarine, and cingulate sulci reached grade 1 were 22, 22, and 26 weeks, respectively. Among 456 included fetuses, 426 showed symmetric cortical development and 30 showed asymmetric cortical development during ultrasound examination. Fetuses with asymmetric cortical development underwent 'catch-up growth' and developed to the same grade in 2-6 weeks. All fetuses with symmetric or asymmetric cortical development had normal neurodevelopment after birth according to ASQ-3 assessment.

CONCLUSION

The gestational age at which the parieto-occipital, calcarine, and cingulate sulci can be detected using ultrasound varies in different studies. Racial differences may be present in cortical development. Normal fetuses may physiologically have mildly asymmetric cortical development in the mesial area.

Chorioamnionitis: An Update on Diagnostic Evaluation

Chorioamnionitis remains a major cause of preterm birth and maternal and neonatal morbidity. We reviewed the current evidence for the diagnostic tests of chorioamnionitis and how this relates to clinical practice today. A comprehensive literature search and review was conducted on chorioamnionitis and intra-uterine inflammation. Data from randomized control trials and systematic reviews were prioritized. This review highlights that sterile inflammation plays an important role in chorioamnionitis and that the current tests for chorioamnionitis including clinical criteria, maternal plasma and vaginal biomarkers lack diagnostic accuracy. Concerningly, these tests often rely on detecting an inflammatory response after damage has occurred to the fetus. Care should be taken when interpreting current investigations for the diagnosis of chorioamnionitis and how they guide obstetric/neonatal management. There is an urgent need for further validation of current diagnostic tests and the development of novel, accurate, minimally invasive tests that detect subclinical intra-uterine inflammation.

Stratification of Amniotic Fluid Cells and Amniotic Fluid by Sex Opens Up New Perspectives on Fetal Health

Amniotic fluid is essential for fetus wellbeing and is used to monitor pregnancy and predict fetal outcomes. Sex affects health and medicine from the beginning of life, but knowledge of its influence on cell-depleted amniotic fluid (AF) and amniotic fluid cells (AFCs) is still neglected. We evaluated sex-related differences in AF and in AFCs to extend personalized medicine to prenatal life. AFCs and AF were obtained from healthy Caucasian pregnant women who underwent amniocentesis at the 16th-18th week of gestation for advanced maternal age. In the AF, inflammation biomarkers (TNFα, IL6, IL8, and IL4), malondialdehyde, nitrites, amino acids, and acylcarnitines were measured. Estrogen receptors and cell fate (autophagy, apoptosis, senescence) were measured in AFCs. TNFα, IL8, and IL4 were higher in female AF, whereas IL6, nitrites, and MDA were similar. Valine was higher in male AF, whereas several acylcarnitines were sexually different, suggesting a mitochondrial involvement in establishing sex differences. Female AFCs displayed higher expression of ERα protein and a higher ERα/ERβ ratio. The ratio of LC3II/I, an index of autophagy, was higher in female AFCs, while LC3 gene was similar in both sexes. No significant sex differences were found in the expression of the lysosomal protein LAMP1, while p62 was higher in male AFCs. LAMP1 gene was upregulated in male AFCs, while p62 gene was upregulated in female ones. Finally, caspase 9 activity and senescence linked to telomeres were higher in female AFCs, while caspase 3 and β-galactosidase activities were similar. This study supports the idea that sex differences start very early in prenatal life and influence specific parameters, suggesting that it may be relevant to appreciate sex differences to cover knowledge gaps. This might lead to improving the diagnosis of risk prediction for pregnancy complications and achieving a more satisfactory monitoring of fetus health, even preventing future diseases in adulthood.

Obstetrical outcomes following amniocentesis performed after 24 weeks of gestation: A systematic review and meta-analysis

To evaluate obstetrical outcomes for women having late amniocentesis (on or after 24 weeks). Electronic databases were searched from inception to January 1st, 2023. The obstetrical outcomes evaluated were gestational age at delivery, preterm birth (PTB) < 37 weeks, PTB within 1 week from amniocentesis, premature prelabor rupture of membranes (pPROM), chorionamnionitis, placental abruption, intrauterine fetal demise (IUFD) and termination of pregnancy (TOP). The incidence of PTB <37 weeks was 4.85% (95% CI 3.48-6.56), while the incidence of PTB within 1 week was 1.42% (95% CI 0.66-2.45). The rate of pPROM was 2.85% (95% CI 1.21-3.32). The incidence of placental abruption was 0.91% (95% CI 0.16-2.25), while the rate of IUFD was 3.66% (95% CI 0.00-14.04). The rate of women who underwent TOP was 6.37% (95%CI 1.05-15.72). When comparing amniocentesis performed before or after 32 weeks, the incidence of PTB within 1 week was 1.48% (95% CI 0.42-3.19) and 2.38% (95% CI 0.40-5.95). Amniocentesis performed late after 24 weeks of gestation is an acceptable option for patients needing prenatal diagnosis in later gestation.

Invasive prenatal diagnosis in the era of cell-free fetal DNA: experience at a single center

BACKGROUND

We aimed to assess procedure-related risk of fetal loss associated with amniocentesis and chorionic villus sampling and compare amniocentesis and chorionic villus sampling with cell-free fetal DNA in identifying chromosomal abnormalities.

METHODS

A retrospective observational study on 4712 women with singleton pregnancy who underwent invasive prenatal diagnosis, from January 2010 to December 2019. Postprocedural miscarriage rate (before 24+0 weeks gestation) was determined for the whole population and for the group of women aged ≥35 years who underwent the procedure for the sole maternal age.

RESULTS

Miscarriage rate following amniocentesis and chorionic villus sampling were 0.50% and 1.25%, respectively. In our population of women undergoing invasive procedure for advanced maternal age cell-free fetal DNA would have identified only the 49 cases of trisomy 21, 13 and 18, whereas the other 21 more subtle chromosomal anomalies, diagnosed by amniocentesis and chorionic villus sampling, would have been missed.

CONCLUSIONS

Patients who opt for cell-free fetal DNA test should be informed of the screening nature of the test and the possibility of false positive results. Invasive prenatal testing has probably lower risks than previously reported and has unquestionable advantages such as the certainty of diagnosis and the ability to detect a higher number of chromosomal abnormalities, when compared with cell-free fetal DNA.

Monochorionic twins with discordant trisomy 21, another case to remind this uncommon condition and how to deal with

Monozygotic twins discordant for trisomy 21 are rare. We present the twelfth reported case of this uncommon condition undergoing invasive prenatal diagnosis. Dealing with discordant fetal anomalies in monochorionic pregnancy can be challenging for physicians and patients; pros and cons of different invasive procedure options must be discussed with the couple, contending with certain specific peculiarities of this type of pregnancy. Although chorionic villi sampling can be performed earlier, higher risk of misdiagnosis of discordant aneuploidy is reported. Indeed, when heterokaryotic twins are suspected, a two-sampling amniocentesis is recommended, to ensure independent sampling of each fetus and to rule out confined placental mosaicism as well. The couple should be informed of the possible management and the risks for the non-affected twin whether selective reduction is required, and likewise if the pregnancy continues without selective termination.

Monitoring medicine prescriptions before, during and after pregnancy in Italy

BACKGROUND

The use of medications during pregnancy is a common event worldwide. Monitoring medicine prescriptions in clinical practice is a necessary step in assessing the impact of therapeutic choices in pregnant women as well as the adherence to clinical guidelines. The aim of this study was to provide prevalence data on medication use before, during and after pregnancy in the Italian population.

METHODS

A retrospective prevalence study using administrative healthcare databases was conducted. A cohort of 449,012 pregnant women (15-49 years) residing in eight Italian regions (59% of national population), who delivered in 2016-2018, were enrolled. The prevalence of medication use was estimated as the proportion (%) of pregnant women with any prescription.

RESULTS

About 73.1% of enrolled women received at least one drug prescription during pregnancy, 57.1% in pre-pregnancy and 59.3% in postpartum period. The prevalence of drug prescriptions increased with maternal age, especially during the 1st trimester of pregnancy. The most prescribed medicine was folic acid (34.6%), followed by progesterone (19%), both concentrated in 1st trimester of pregnancy (29.2% and 14.8%, respectively). Eight of the top 30 most prescribed medications were antibiotics, whose prevalence was higher during 2nd trimester of pregnancy in women ≥ 40 years (21.6%). An increase in prescriptions of anti-hypertensives, antidiabetics, thyroid hormone and heparin preparations was observed during pregnancy; on the contrary, a decrease was found for chronic therapies, such as anti-epileptics or lipid-modifying agents.

CONCLUSIONS

This study represents the largest and most representative population-based study illustrating the medication prescription patterns before, during and after pregnancy in Italy. The observed prescriptive trends were comparable to those reported in other European countries. Given the limited information on medication use in Italian pregnant women, the performed analyses provide an updated overview of drug prescribing in this population, which can help to identify critical aspects in clinical practice and to improve the medical care of pregnant and childbearing women in Italy.

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.

Amniocentesis-When It Is Clear That It Is Not Clear

A fetus identified to be at risk for chromosomal abnormalities may benefit from identification of genetic defects through amniocentesis. Although the risks associated with amniocentesis are considered to be minimal, being an invasive procedure it is not completely without complications.

BACKGROUND AND OBJECTIVES

The current study aims to identify correlations between blood contamination of samples collected during amniocentesis and certain factors dependent on the instruments used (thickness of the needle used to aspirate the fluid), the location of the placenta, and uterine vascularity (more pronounced in multiparous patients).

MATERIALS AND METHODS

The study included 190 patients in the second trimester of pregnancy who met one of the criteria for invasive prenatal diagnosis (age over 35 years, high risk in first trimester screening, history of pregnancies with genetic abnormalities, etc.). The amniotic fluid samples collected from these patients were analyzed in terms of blood contamination of the amniotic fluid aspirated with maternal cells Results: Of the patients in whom the procedure was performed using 21 G size needles, 16 samples (13.33% of the total) were contaminated. None of the samples collected from patients where a 20 G needle was used were contaminated. There was a statistically significant association between the lack of contamination and the use of Doppler ultrasound in multiparous patients with anterior placenta in whom a 21-gauge needle was used for amniocentesis.

CONCLUSIONS

There is an increased rate of sample contamination (statistically significant) when using 21 G needle sizes and a significant difference in contamination between primiparous and multiparous patients, with contamination being more frequent in multiparous patients. The use of Doppler ultrasonography may benefit the procedure, as the contamination rate was significantly reduced when used during amniocentesis.

The Association between the Bisphenols Residues in Amniotic Fluid and Fetal Abnormalities in Polish Pregnant Women-Its Potential Clinical Application

The present study aimed to investigate the relationship between the concentrations of bisphenols residues in the amniotic fluid (AF) samples collected during amniocentesis and fetal chromosomal abnormalities in pregnant women. A total of 33 pregnant Polish women aged between 24 and 44 years, and screened to detect high risk for chromosomal defects in the first trimester, were included in this study. Samples were collected from these patients during routine diagnostic and treatment procedures at mid-gestation. The concentrations of various bisphenols residues in the samples were determined by liquid chromatography coupled with triple quadrupole tandem mass spectrometry (LC-ESI-QqQ-MS/MS). Residues of eight analytes (BPS, BPF, BPA, BPAF, BADGE, BADGE•2H₂O, BADGE•H₂O•HCl and BADGE•2HCl) were detected in amniotic fluid samples in the range 0.69 ng/mL to 3.38 ng/mL. Fetuses with chromosomal abnormalities showed a slightly higher frequency of occurrence of selected bisphenols residues in the AF samples collected between 15-26 weeks of pregnancies. Finally, the proposed method was applied in the simultaneous determination of several endocrine-disrupting chemicals from bisphenol group in 33 human AF samples. BADGE•H2O•HCl has been identified in the AF samples taken from women older than average in the examined group. The number of detected compounds has been significant for the following analytes: BPS, BPAF, BADGE•H₂O•HCl and BADGE. The proposed method may be an attractive alternative for application in large-scale human biomonitoring studies.

Do online decision aids reflect new prenatal screening and testing options? An environmental scan and content analysis

Objective

Decision aids have been developed to help prospective parents make informed, shared decisions about medical tests, but these options are rapidly changing. This study aimed to identify and evaluate publicly available decision aids written in English for prospective parents seeking prenatal test information.

Methods

A systematic review process was followed using 3 sources: known decision aid repositories, fetal medicine organisations and Google. The search, screening process, quality assessment, and data extraction was performed by two independent researchers. The quality assessment of the decision aids was based on the International Patient Decision Aids Standards (IPDAS v.4.0).

Results

We identified 13 decision aids, which varied in the screening and diagnostic tests that they discussed. No decision aid met all the IPDAS v.4.0. criteria and no decision aid reported updated risk of miscarriage for amniocentesis and chorionic villus sampling (CVS). There was a lack of decision aids for some common decisions in the prenatal context.

Conclusion

We identified outdated content in current prenatal decision aids. The findings will inform healthcare professionals of the quality of current prenatal decision aids, which may facilitate their patients' informed decision-making about prenatal tests.

Innovation

Considerations for improving future decision aids are outlined.

Foetal loss after chorionic villus sampling and amniocentesis in twin pregnancies: A multicentre retrospective cohort study

OBJECTIVE

We aimed to determine foetal losses for DCDA and MCDA twins following transabdominal CVS or amniocentesis performed <22+⁰  weeks.

METHODS

Retrospective cohort study conducted in the UK and Belgium 01/01/00-01/06/20. Cases with unknown chorionicity, monochorionic complications or complex procedures were excluded. Uncomplicated DCDA and MCDA twins without invasive procedures were identified as controls. We reported foetal losses <24+⁰  weeks and losses of genetically and structurally normal foetuses.

RESULTS

Outcomes were compared for DCDA foetuses; 258 after CVS with 3406 controls, 406 after amniocentesis with 3390 controls plus MCDA foetuses, 98 after CVS with 1124 controls, and 160 after amniocentesis with 1122 controls. There were more losses <24+⁰  weeks with both procedures in DCDA (CVS RR 5.54 95% CI 3.38-9.08, amniocentesis RR 2.36 95% CI 1.22-4.56) and MCDA twins (CVS RR 5.14 95% CI 2.51-10.54, amniocentesis RR 7.01 95% CI 3.86-12.74). Losses of normal foetuses were comparable to controls (DCDA CVS RR 0.39 95% CI 0.05-2.83, DCDA amniocentesis RR 1.16 95% CI 0.42-3.22, MCDA CVS RR 2.3 95% CI 0.71-7.56, and MCDA amniocentesis RR 1.93 95% CI 0.59-6.38).

CONCLUSIONS

This study indicates increased foetal losses for DCDA and MCDA twins following CVS and amniocentesis with uncertain risk to normal foetuses.

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.

Does a High-Risk (>1/50) Result for First-Trimester Combined Screening Always Entail Invasive Testing? Which Patients from This Group Might Benefit from cfDNA Testing?

Currently, cell-free DNA (cfDNA) is offered as part of a contingent screening for patients with a first-trimester combined test (FCT) risk between 1/50 and 1/250. However, most aneuploidies are within the group of patients with a risk above 1/10. An observational, retrospective, and multi-centric study was carried out, to evaluate the theorical performance of lowering the cut-off point for the high-risk group from 1/50 to 1/10. Out of the 25,920 patients included, 25,374 (97.9%) consented to the cfDNA contingent screening for aneuploidies. With the proposed strategy, knowing that the detection rate (DR) of cfDNA testing for trisomy 21 is 99.7%, the DR for trisomy 21 would have stayed in a 93.2%, just as it was with the current strategy. In this instance, 267 (1.1%) invasive tests would have been performed, while the current strategy had a total of 307 (1.2%). The false positive rate (FPR) rate would have stayed at 5.2% in both scenarios. In conclusion, the contingent screening of aneuploidies based in the result of the FCT, offering the analysis of cfDNA to patients with an intermediate risk after lowering the cut-off point from 1/50 to 1/10, is a valid alternative that might maintain the current detection rates and avoid the complications associated with invasive testing.

First and Second Level Haemoglobinopathies Diagnosis: Best Practices of the Italian Society of Thalassemia and Haemoglobinopathies (SITE)

The purpose of this best practice paper is to review the current recommendations for the identification and prenatal diagnosis of hemoglobinopathies. Methods: The management committee of SITE selected and gathered a multidisciplinary team in order to formulate recommendations based on the available scientific evidence integrated with the opinions of experts, with the purpose of supporting clinicians. Results: We provide recommendations for first level tests (complete blood count, hemoglobin separation and iron balance), second level tests (molecular diagnosis) and prenatal diagnosis. Five Italian experts in hemoglobinopathies were consulted regarding the orientation of prenatal diagnosis, and for each indication, the degree of agreement among the experts has been specified. Conclusions: Best practice recommendations are the final outcome of this translational research and allow transfer to daily clinical practice.

Clinical Assessment of Fetal Well-Being and Fetal Safety Indicators

Delivering safe clinical trials of novel therapeutics is central to enable pregnant women and their babies to access medicines for better outcomes. This review describes clinical monitoring of fetal well‐being and safety. Current pregnancy surveillance includes regular antenatal checks of blood pressure and urine for signs of gestational hypertension. Fetal and placental development is assessed routinely using the first‐trimester “dating” and mid‐trimester “anomaly” ultrasound scans, but the detection of fetal anomalies can continue throughout pregnancy using targeted sonography or magnetic resonance imaging (MRI). Serial sonography can be used to assess fetal size, well‐being, and placental function. Carefully defined reproducible imaging parameters, such as the head circumference (HC), abdominal circumference (AC), and femur length (FL), are combined to calculate an estimate of the fetal weight. Doppler analysis of maternal uterine blood flow predicts placental insufficiency, which is associated with poor fetal growth. Fetal doppler analysis can indicate circulatory decompensation and fetal hypoxia, requiring delivery to be expedited. Novel ways to assess fetal well‐being and placental function using MRI, computerized cardiotocography (CTG), serum circulating fetoplacental proteins, and mRNA may improve the assessment of the safety and efficacy of maternal and fetal interventions. Progress has been made in how to define and grade clinical trial safety in pregnant women, the fetus, and neonate. A new system for improved safety monitoring for clinical trials in pregnancy, Maternal and Fetal Adverse Event Terminology (MFAET), describes 12 maternal and 18 fetal adverse event (AE) definitions and severity grading criteria developed through an international modified Delphi consensus process. This fills a vital gap in maternal and fetal translational medicine research.

Non-invasive prenatal testing in mitigating concerns from invasive prenatal diagnostic testing: retrospective assessment of utility in an academic healthcare system in the US

OBJECTIVE

Non-invasive prenatal testing (NIPT) is a front-line screening for fatal chromosomal aneuploidy. In pregnant women with a risk of having fetal congenital disorders, NIPT is anticipated to reduce the needs of invasive prenatal diagnostic test (IPD). The objective of this study was to understand the acceptance of NIPT and the utility of NIPT to mitigate concerns about IPD in the US high-risk pregnancy management.

DESIGN AND SETTING

This was a retrospective observational research using healthcare records obtained from an academic healthcare system in the US. The study consisted of site-level longitudinal analysis and patient-level cross-sectional analysis.

PARTICIPANT

A total of 5660 new high-risk pregnancies with age ≥35 years were identified for the longitudinal trend analysis. Cross-sectional utility assessment included 2057 pregnant women.

EXPOSURE AND OUTCOME MEASURES

Longitudinal trends of NIPT order, IPD procedure and the number of patients diagnosed with high-risk pregnancy were descriptively summarised. In the cross-sectional assessment, we tested the association between the use of NIPT and IPD using multivariable regression.

RESULTS

The rate of increase in the NIPT use exceeded the changes in the number of high-risk pregnancies with age ≥35 years, while the number of annual IPD procedures has fluctuated without specific trends. There was no significant association between the numbers of NIPT and IPD with the adjusted ORs between 0.90 and 1.14 (p>0.1). The order of NIPT was not selected as an independent variable predicting the use of IPD. Clinical characteristics indicating low socioeconomic status and limited healthcare coverage are associated with less use of NIPT and lower clinical utility.

CONCLUSION

Although prenatal care accepted NIPT over the last decade, the utility of NIPT in mitigating concerns on IPD is unclear and needs further investigation. Limited clinical utility should be addressed in the context of disparity in prenatal care.

Ultrasonic Needle Tracking with Dynamic Electronic Focusing

Accurate identification of the needle tip is a key challenge with ultrasound-guided percutaneous interventions in regional anaesthesia, foetal surgery and cardiovascular medicine. In this study, we developed an ultrasonic needle tracking system in which the measured needle tip location was used to set the electronic focus of the external ultrasound imaging probe. In this system, needle tip tracking was enabled with a fibre-optic ultrasound sensor that was integrated into a needle stylet, and the A-lines recorded by the sensor were processed to generate tracking images of the needle tip. The needle tip position was estimated from the tracking images. The dependency of the tracking image on the electronic focal depth of the external ultrasound imaging probe was studied in a water bath and with needle insertions into a clinical training phantom. The variability in the estimated tracked position of the needle tip, with the needle tip at fixed depths in the imaging plane across a depth range from 0.5 to 7.5 cm, was studied. When the electronic focus was fixed, the variability of tracked position was found to increase with distance from that focus. The variability with the fixed focus was found to depend on the the relative distance between the needle tip and focal depth. It was found that with dynamic focusing, the maximum variability of tracked position was below 0.31 mm, as compared with 3.97 mm for a fixed focus.

Association of prenatal renal ultrasound abnormalities with pathogenic copy number variants in a large Chinese cohort

OBJECTIVES

To assess the clinical utility of prenatal chromosomal microarray analysis (CMA) in fetuses with abnormal renal sonographic findings, and to evaluate the association of pathogenic or likely pathogenic copy number variants (P/LP CNVs) with different types of renal abnormality.

METHODS

This was a retrospective study of fetuses at 14-36 weeks screened routinely for renal and other structural abnormalities at the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region. We retrieved and analyzed data from fetuses with abnormal renal sonographic findings, examined between January 2013 and November 2019, which underwent CMA analysis using tissue obtained from chorionic villus sampling (CVS), amniocentesis or cordocentesis. We evaluated the CMA findings according to type of renal ultrasound anomaly and according to whether renal anomalies were isolated or non-isolated.

RESULTS

Ten types of renal anomaly were reported on prenatal ultrasound screening, at a mean ± SD gestational age of 24.9 ± 4.8 weeks. The anomalies were diagnosed relatively late in this series, as 64% of cases with an isolated renal anomaly underwent cordocentesis rather than CVS. Fetal pyelectasis was the most common renal ultrasound finding, affecting around one-third (34.32%, 301/877) of fetuses with a renal anomaly, but only 3.65% (n = 11) of these harbored a P/LP CNV (comprising: isolated cases, 2.37% (4/169); non-isolated cases, 5.30% (7/132)). Hyperechogenic kidney was found in 5.47% (n = 48) of fetuses with a renal anomaly, of which 39.58% (n = 19) had a P/LP CNV finding (comprising: isolated cases, 44.44% (16/36); non-isolated cases, 25.00% (3/12)), the highest diagnostic yield among the different types of renal anomaly. Renal agenesis, which accounted for 9.92% (n = 87) of all abnormal renal cases, had a CMA diagnostic yield of 12.64% (n = 11) (comprising: isolated cases, 11.54% (9/78); non-isolated cases, 22.22% (2/9); unilateral cases, 11.39% (9/79); bilateral cases, 25.00% (2/8)), while multicystic dysplastic kidney (n = 110), renal cyst (n = 34), renal dysplasia (n = 27), crossed fused renal ectopia (n = 31), hydronephrosis (n = 98), renal duplication (n = 42) and ectopic kidney (n = 99) had overall diagnostic rates of 11.82%, 11.76%, 7.41%, 6.45%, 6.12%, 4.76% and 3.03%, respectively. Compared with the combined group of CMA-negative fetuses with any other type of renal anomaly, the rate of infant being alive and well at birth was significantly higher in CMA-negative fetuses with isolated fetal pyelectasis or ectopic kidney, whereas the rate was significantly lower in fetuses with isolated renal agenesis, multicystic dysplastic kidney or severe hydronephrosis. The most common pathogenic CNV was 17q12 deletion, which accounted for 30.14% (22/73) of all positive CMA findings, with a rate of 2.51% (22/877) among fetuses with an abnormal renal finding. Fetuses with 17q12 deletion exhibited a wide range of renal phenotypes. Other P/LP CNVs in the recurrent region that were associated with prenatal renal ultrasound abnormalities included 22q11.2, Xp21.1, Xp22.3, 2q13, 16p11.2 and 1q21, which, collectively, accounted for 2.17% (19/877) of the fetuses with prenatal renal anomalies.

CONCLUSIONS

In this retrospective review of CMA findings in a large cohort of fetuses with different types of renal ultrasound abnormality, the P/LP CNV detection rate varied significantly (3.03-39.58%) among the different types of kidney anomaly. Our data may help in the decision regarding whether to perform prenatal genetic testing in fetuses with renal ultrasound findings. Specifically, prenatal CMA testing should be performed in cases of hyperechogenic kidney, regardless of whether or not the anomaly is isolated, while it should be performed postnatally rather than prenatally in cases of fetal pyelectasis. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal Invasive Testing at a Tertiary Referral Center in India: A Report of 433 Cases Under a Single Operator

PURPOSE OF THE STUDY

Chromosomal aneuploidies are major causes of perinatal death and childhood handicap. Awareness about screening and prenatal diagnosis for these disorders among obstetricians and primary care physicians is increasing. Since invasive tests like amniocentesis or chorionic villus sampling (CVS) are associated with a risk of miscarriage these tests should be carried out judiciously in pregnancies considered to be at high risk for aneuploidies and other genetic disorders. The purpose of our study was to examine the patterns, trends and outcomes of the various screening procedures and invasive tests results.

METHODOLOGY

Retrospective observational study done over a period of 3 years and one month including 433 pregnant women with high risk for genetic disorders undergoing invasive prenatal testing like chorionic villus sampling, amniocentesis or cordocentesis. Data were collected from our department records regarding the maternal age, indication for invasive testing, past obstetric history, family history of genetic syndromes, ultrasound findings in the current sonographic examination and the results of the tests done. Any immediate or late complications of the procedure if any were telephonically addressed.

RESULTS

A total of 436 procedures on 433 patients (418 singleton,12 single fetus of twin, 3 both fetuses of twins) were done out of which 281 were amniocentesis(64.4%), 153 were chorionic villus sampling (35.1%) and 2 were cordocentesis(< 1%). Of the 436 procedures, 373(85.5%) were done for positive screening tests for chromosomal aneuploidies and 63(14.4%) were done for previous history of genetic syndromes. The positive predictive value of biochemical marker alone was around 2.7% and higher around 13% for a combined first trimester or a second-trimester screen along with ultrasound abnormalities. The higher the biochemical risk does not translate into higher chance of chromosomal abnormality. Nineteen percentage of fetuses with NT above 95th centile had chromosomal abnormality. Twenty-one percentage of fetuses with absent nasal bone in our study had trisomy 21.

CONCLUSION

Aneuploidy screening is the most common indication for prenatal invasive testing with dual marker combined with nuchal translucency, nasal bone, tricuspid regurgitation and ductus venosus flow providing the best detection rates. The chance of an affected fetus in a patient with aneuploidy screen positive overall is only 6.7%.

X Chromosome Inactivation Pattern and Pregnancy Outcome of Female Carriers of Pathogenic Heterozygous X-Linked Deletions

Prenatal risk assessment of carriers of heterozygous X-linked deletion is a big challenge due to the phenotypic modification induced by X chromosome inactivation (XCI). Herein, we described four Chinese pedigrees with maternal-inherited X-deletions above 1 Mb. The pathogenic evaluation revealed that all X-deletions are harmful to heterozygous carriers; however, the asymptomatic pregnant female carriers in these families tremendously complicate the prognostic assessment of the unborn heterozygous embryos. In this study, we detected the XCI pattern of 11 female carriers of heterozygous X-linked deletions and 4 non-carrier females in these families and performed the first prenatal XCI pattern analysis in a fetal female carrier of heterozygous PCDH19-deletion to make risk prediction. In an adult female who lost one copy of the terminal of X chromosome short arm (Xp), a region enriching a large number of XCI escapees, the expression level of representative XCI escape genes was also detected. Pregnancy outcomes of all families were followed up or retrospected. Our research provides clinical evidence that X-deletions above 1 Mb are indeed associated with extremely skewed XCI. The favorable skewed XCI in combination with potential compensatory upregulation of XCI escapees would protect some but not all female carriers with pathogenic X-deletion from severe clinical consequences, mainly depending on the specific genetic contents involved in the deletion region. For PCDH19-disorder, the XCI pattern is considered as the decisive factor of phenotype expression, of which prenatal XCI assay using uncultured amniocytes could be a practicable way for risk prediction of this disease. These results provide valuable information about the usage of XCI assay in the prenatal risk assessment of heterozygous X-linked deletions.

Consensus on Training and Assessment of Competence in Performing Chorionic Villus Sampling and Amniocentesis: An International Delphi Survey

INTRODUCTION

The aim of this study was to obtain expert consensus on the content of a curriculum for learning chorionic villus sampling (CVS) and amniocentesis (AC) and the items of an assessment tool to evaluate CVS and AC competence.

METHODS

We used a 3-round iterative Delphi process. A steering committee supervised all processes. Seven international collaborators were identified to expand the breadth of the study internationally. The collaborators invited fetal medicine experts to participate as panelists. In the first round, the panelists suggested content for a CVS/AC curriculum and an assessment tool. The steering committee organized and condensed the suggested items and presented them to the panelists in round 2. In the second round, the panelists rated and commented on the suggested items. The results were processed by the steering committee and presented to the panelists in the third round, where final consensus was obtained. Consensus was defined as support by more than 80% of the panelists for an item.

RESULTS

Eighty-six experts agreed to participate in the study. The panelists represented 16 countries across 4 continents. The final list of curricular content included 12 theoretical and practical items. The final assessment tool included 11 items, systematically divided into 5 categories: pre-procedure, procedure, post-procedure, nontechnical skills, and overall performance. These items were provided with behavioral scale anchors to rate performance, and an entrustment scale was used for the final overall assessment.

CONCLUSION

We established consensus among international fetal medicine experts on content to be included in a CVS/AC curriculum and on an assessment tool to evaluate CVS/AC skills. These results are important to help transition current training and assessment methods from a time- and volume-based approach to a competency-based approach which is a key step in improving patient safety and outcomes for the 2 most common invasive procedures in fetal medicine.

Prenatal Diagnosis Nomograms: A Novel Tool to Predict Fetal Chromosomal Abnormalities in High-Risk Patients

Background

Amniocentesis is an invasive prenatal diagnostic technique that can provide genetic information of fetus for pregnant women and give them a choice. A straightforward predictive tool can show pregnant women the need for amniocentesis prior to the procedure.

Methods

The information of patients who underwent amniocentesis from 2014 to 2019 at the Obstetrics Clinic, Shengjing Hospital of China Medical University was extracted, and important independent prognostic factors were determined by univariate and multivariate logistic regression analysis to construct nomograms with total abnormalities (TA) and chromosome number abnormalities (CNA).

Results

A total of 19,683 patients undergoing amniocentesis were included in this study. Among 1761 patients with abnormal results, 917 had abnormal chromosome numbers, 439 had abnormal chromosome structures, and 405 had polymorphic results. Nomograms of TA and CNA were created using data such as age, nuchal translucency value, ultrasound results, Oscar’s testing and/or non-invasive prenatal testing abnormalities, parental chromosomes, and information whether they were twins. The nomogram has good predictive power and clinical practicality through the analysis of area under curve and decision curve analysis. Internal verification was performed for nomograms of TA and CNA, suggesting that the nomogram’s predicted probability and actual probability of the two are consistent.

Conclusion

The nomogram constructed is a good predictor of TA and CNA, which can be used in clinical practice to screen high-risk patients of chromosomal abnormalities.

Application of expanded noninvasive prenatal test in prenatal diagnosis of fetuses with increased nuchal translucency

OBJECTIVES

To investigate the efficiency of the upgraded noninvasive prenatal test (NIPT-Plus) in fetuses with increased nuchal translucency (NT).

METHODS

Fetuses with an increased NT at or above 2.5 mm were selected for prenatal diagnosis. Amniotic fluid was collected from all cases for karyotype analysis and copy number variation sequencing (CNV-seq), and cell-free fetal DNA (cfDNA) in maternal blood was tested using Noninvasive Prenatal Test (NIPT-Plus) before amniocentesis in some cases. The results of amniocentesis with different NT thicknesses were analyzed and compared with those of NIPT-Plus.

RESULTS

A total of 125 eligible patients were divided into group A (2.5 mm ≤ NT < 3.0 mm) and group B (NT ≥ 3.0 mm). In group A, the detection rate of chromosomal aneuploidy and pathogenic copy number variation (CNV) was 10.6% and 6.4%, respectively. The total chromosome abnormality rate in group B (34.7%) was significantly higher than that in group A (17%). In 72 patients who underwent NIPT-Plus and amniocentesis, chromosomal aneuploidy accounted for 80.8% of the total chromosomal abnormalities. Among 21 cases of chromosomal aneuploidy, NIPT-Plus detected 20 cases. The sensitivity and specificity of NIPT-Plus toward aneuploidy detection were 95.2% and 100%, respectively. Among the five cases of pathogenic CNV, only two were detected using NIPT-Plus.

CONCLUSION

NIPT-plus is recommended as the first choice for fetal diagnosis in pregnant women with 2.5 mm ≤ NT < 3.0 mm who do not accept invasive prenatal diagnosis. When NT ≥ 3.0 mm and NIPT-Plus detects chromosomal aneuploidy, a rapid prenatal diagnosis can be performed through amniocentesis. In cases where NIPT-Plus yields negative results, amniocentesis still needs to be performed to detect chromosome microdeletions/duplications in order to avoid a missed diagnosis.

New evidence on prognostic features, prevention and treatment of congenital Cytomegalovirus infection

PURPOSE OF REVIEW

Congenital Cytomegalovirus (CMV) infection remains a major cause of lifelong disability, with no systematic screening implemented in pregnancy or the postnatal period. In this review article, we outline the preventive strategies, antenatal prognostic features and experimental therapies as well as evidence of efficacy from recent trials.

RECENT FINDINGS

A recent randomized, double blinded, placebo-controlled study investigated the efficacy of Valaciclovir in women contracting primary CMV in the periconception period or first trimester. They concluded that Valaciclovir at a dose of 8 g/day is effective in reducing the rate of foetal CMV infection following early maternal primary infection. Administration of CMV hyperimmune globulin (HIG) was investigated in a recent randomized double-masked controlled trial. This study concluded that CMV HIG was ineffective at reducing the risk of congenital CMV among women with primary CMV in early pregnancy.

SUMMARY

Congenital CMV infection remains a significant cause of disability. There is currently no vaccine available, with the best preventive strategy being patient education on transmission as well as hygiene measures to reduce risk of exposure. Experimental therapies have been investigated in recent years and there is evidence supporting the use of Valaciclovir. Data for the efficacy of CMV HIG remains inconsistent and administration is currently limited to clinical trial settings.

Screening, Management and Delivery in Twin Pregnancy

The following AWMF guideline (DGGG/AGG & DEGUM responsible) deals with the diagnosis, screening and management of twins as well as the timing and mode of birth.Twin pregnancies can be classified as dichorionic diamniotic (DC DA), monochorionic diamniotic (MC DA) and monochorionic monoamniotic (MC MA) which are always monochorionic.Twin pregnancies can be concordant (both twins are affected) or discordant (only one twin is affected) for chromosomal defects, malformations, growth restriction and hemodynamic disorders.Chorionicity is the prognostically most significant parameter. Monochorial twins have significantly higher risks of intrauterine morbidity and mortality compared to dichorial twins.In particular, general aspects of twin pregnancies such as dating, determination of chorionicity and amnionicity, the labeling of twin fetuses and the perinatal switch phenomenon are discussed.Routine monitoring of MC and DC twin pregnancies with ultrasound at 11-13^+ 6 weeks of gestation for chromosomal defects, invasive prenatal diagnosis, first-trimester NT or CRL discrepancies, early diagnosis of fetal anatomical defects, and management of twins with abnormalities, including selective fetocide, is described.Second trimester screening and management for preterm birth, intrauterine selective growth restriction (sFGR), classification of monochorial twins with sFGR, and management of the surviving twin after the death of the co-twin are described.Complications exclusively affecting MC twins include Twin to Twin Transfusion Syndrome (TTTS) with the important topics screening, prognosis, complications of laser therapy, timing of delivery, risks for brain abnormalities and delayed neurological development, Twin Anemia-Polycythemia Sequence (TAPS) and Twin Reversed Arterial Perfusion (TRAP) Sequence. This also includes MC MA twins as well as conjoined twins.Finally, the birth mode and time for DC and MC twin pregnancies are described.The information is summarized in 62 recommendations for action, 4 tables and 8 illustrations with comprehensive background texts.The guideline is an international guideline adaptation (ISUOG, NICE) as well as a systematic literature search and is up-to-date.

Risk of mother-to-child transmission of hepatitis B virus after fetal blood sampling: a report of six cases

BACKGROUND

Hepatitis B virus (HBV) remains a major global public health problem worldwide; in endemic areas, mother-to-child transmission (MTCT) of HBV is the most common transmission route. Previous studies have shown that amniocentesis for prenatal diagnosis increases the risk of MTCT of HBV among highly viraemic mothers. However, no data is available on MTCT related fetal blood sampling (FBS) because of the paucity of cases or lack of attention. We present a case series of HBV-infected women who underwent FBS with or without antiviral therapy during pregnancy and discuss the risk of MTCT after FBS.

CASE PRESENTATION

Six hepatitis B surface antigen (HBsAg)-positive pregnant women who underwent FBS for prenatal diagnosis were retrospectively reviewed. Their infants were followed up with HBV serology parameters until at least 12 months of age. Among 6 cases, two hepatitis B e-antigen (HBeAg)-positive mothers had high viral loads > 7.0 log₁₀ IU/mL, and one of them received antiviral therapy at 26^+ 3 gestational weeks and achieved an anticipated level of 4.52 log₁₀ IU/mL before FBS, while the other one did not receive any antiviral treatment. The other 4 cases were HBeAg-negative with low viral loads. Only a child born to the HBeAg-positive mother, who had no antiviral therapy with a viral load of 7.48 log₁₀ IU/mL before FBS, was found to have MTCT with HBsAg persistently positive from birth to 12 months of age. The other 5 children were both HBsAg-negative and HBsAb-positive at the end of follow-up.

CONCLUSIONS

FBS may increase the risk of MTCT of HBV in women with HBeAg-positive and high viral loads; therefore, FBS should be avoided in this high-risk population. Maternal HBV serologic testing and awareness of the potential risk of MTCT should be recommended before FBS. Antiviral therapy may be effective to decrease the risk of MTCT after FBS in highly viraemic women.

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.

Clinical management of pregnancies with positive screening results for rare autosomal aneuploidies at a single center

Objective

To review our experiences on clinical management of pregnancies with positive noninvasive prenatal testing (NIPT) results for rare autosomal aneuploidies (RAAs) at a single center.

Methods

We performed a retrospective study and reviewed data from 18,016 pregnancies undergoing NIPT at a single center in China from March 2017 to February 2020. Depending on the patient’s choice, women with positive screening results for RAAs underwent chromosomal microarray analysis for invasive prenatal diagnosis.

Results

Thirty-three positive cases for RAAs were identified, with a positive screening rate of 0.18%. The most common RAA was trisomy 7 (33.3%), while trisomies for other chromosomes were less frequent. Monosomies involving chromosomes 16, 14, and 22 were observed. Twenty-eight cases of RAAs underwent invasive diagnosis. Abnormal pregnancy outcomes were observed in four cases, including true fetal mosaicism (n=1), partial uniparental disomy (n=1), miscarriage (n=1), and structural anomalies on ultrasound (n=1).

Conclusions

RAAs at NIPT might be associated with fetal uniparental disomy, mosaic aneuploidy, and poor pregnancy outcomes, but most positive cases have normal pregnancy outcomes. For RAAs, genetic counseling on the potential risks of abnormal NIPT results, as well as on benefits and limitations of invasive prenatal diagnosis, might help guide clinical management.

Confined placental mosaicism and the association with pregnancy outcome and fetal growth: a review of the literature

BACKGROUND

Chromosomal mosaicism can be detected in different stages of early life: in cleavage stage embryos, in blastocysts and biopsied cells from blastocysts during preimplantation genetic testing for aneuploidies (PGT-A) and later during prenatal testing, as well as after birth in cord blood. Mosaicism at all different stages can be associated with adverse pregnancy outcomes. There is an onward discussion about whether blastocysts diagnosed as chromosomally mosaic by PGT-A should be considered safe for transfer. An accurate diagnosis of mosaicism remains technically challenging and the fate of abnormal cells within an embryo remains largely unknown. However, if aneuploid cells persist in the extraembryonic tissues, they can give rise to confined placental mosaicism (CPM). Non-invasive prenatal testing (NIPT) uses cell-free (cf) DNA released from the placenta in maternal blood, facilitating the detection of CPM. In literature, conflicting evidence is found about whether CPM is associated with fetal growth restriction (FGR) and/or other pregnancy outcomes. This makes counselling for patients by clinicians challenging and more knowledge is needed for clinical decision and policy making.

OBJECTIVE AND RATIONALE

The objective of this review is to evaluate the association between CPM and prenatal growth and adverse pregnancy outcomes. All relevant literature has been reviewed in order to achieve an overview on merged results exploring the relation between CPM and FGR and other adverse pregnancy outcomes.

SEARCH METHODS

The following Medical Subject Headings (MESH) terms and all their synonyms were used: placental, trophoblast, cytotrophoblast, mosaicism, trisomy, fetal growth, birth weight, small for gestational age and fetal development. A search in Embase, PubMed, Medline Ovid, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL) and Google Scholar databases was conducted. Relevant articles published until 16 July 2020 were critically analyzed and discussed.

OUTCOMES

There were 823 articles found and screened based on their title/abstract. From these, 213 articles were selected and full text versions were obtained for a second selection, after which 70 publications were included and 328 cases (fetuses) were analyzed. For CPM in eight different chromosomes (of the total 14 analyzed), there was sufficient evidence that birth weight was often below the 5th percentile of fetal growth standards. FGR was reported in 71.7% of CPM cases and preterm birth (<37 weeks of delivery) was reported in 31.0% of cases. A high rate of structural fetal anomalies, 24.2%, in cases with CPM was also identified. High levels of mosaicism in CVS and presence of uniparental disomy (UPD) were significantly associated with adverse pregnancy outcomes.

WIDER IMPLICATIONS

Based on the literature, the advice to clinicians is to monitor fetal growth intensively from first trimester onwards in case of CPM, especially when chromosome 2, 3, 7, 13, 15, 16 and 22 are involved. In addition to this, it is advised to examine the fetuses thoroughly for structural fetal anomalies and raise awareness of a higher chance of (possibly extreme) premature birth. Despite prematurity in nearly a fifth of cases, the long-term follow-up of CPM life borns seems to be positive. More understanding of the biological mechanisms behind CPM will help in prioritizing embryos for transfer after the detection of mosaicism in embryos through PGT-A.

Prenatal chromosomal microarray analysis in 2466 fetuses with ultrasonographic soft markers: a prospective cohort study

BACKGROUND

Soft markers are nonspecific findings detected by ultrasonography during the second trimester that are often transient and nonpathologic but may imply an increased risk of underlying fetal aneuploidy. However, large-scale prospectively stratified studies focusing on the prevalence of chromosomal aberrations, including copy number variants, in fetuses with different types of isolated soft markers have rarely been published in the literature.

OBJECTIVE

This study aimed to investigate clinical outcomes in fetuses with isolated soft markers by single nucleotide polymorphism array with long-term follow-up and to propose a diagnostic algorithm based on specific types of soft markers.

STUDY DESIGN

The prevalence of fetal isolated soft markers was 13.2% (7869 of 59,503). A total of 2466 fetuses with ultrasonographic soft markers during the second trimester, which were subjected to single nucleotide polymorphism array with long-term follow-up, were selected in this prospective study over a 5-year period. Soft markers were categorized into 12 groups. The demographic profile and chromosomal microarray analysis detection results were analyzed and compared among different groups.

RESULTS

The overall prevalence of chromosomal aberrations in fetuses with soft markers was 4.3% (107 of 2466), which comprised 40.2% with numeric chromosomal abnormalities, 48.6% with pathogenic copy number variants, and 11.2% with likely pathogenic copy number variants. The incidence of numeric chromosomal abnormalities was significantly higher in multiple soft markers (5.5% vs 1.5%; P=.001) and the thickened nuchal fold group (8.3% vs 1.7%; P=.024). Meanwhile, the incidence of pathogenic copy number variants was significantly higher in multiple soft markers (5.5% vs 2.4%; P=.046) and the short femur length group (6.6% vs 2.2%; P<.0001). The incidences of pathogenic copy number variants in fetuses with isolated echogenic intracardiac focus, enlarged cisterna magna, choroid plexus cysts, echogenic bowel, or single umbilical artery were lower than 1.5%. The normal infant rate in fetuses without chromosomal aberrations was 91.7%; however, it was significantly lower in the mild ventriculomegaly (86.2% vs 93.0%; P<.0001) and short femur length groups (71.4% vs 93.6%; P<.0001).

CONCLUSION

The potential chromosomal aberrations and clinical prognoses varied widely among different types of isolated soft markers. Pathogenic copy number variants are more often present in specific soft markers, especially when multiple soft markers are found. Thus, a specific soft marker type-based prenatal genetic testing algorithm was proposed.

Comparison of cord blood hematological parameters among normal, α-thalassemia, and β-thalassemia fetuses between 17 and 38 weeks of gestation

The aim of this study was to retrospectively compare hematological parameters among normal, α-, and β-thalassemia fetuses between 17 and 38 weeks of gestation. Pregnant women at risk of having fetuses with thalassemia major and underwent cordocentesis for prenatal diagnosis were recruited. Fetal cord blood samples were collected from 249 fetuses for hematological and DNA analysis. Fetuses were divided into subgroups according to thalassemia DNA genotypes. The average and gestational age of subjects were 27.95 ± 5.78 years and 27.78 ± 3.57 weeks, respectively. The distribution of α-thalassemia, β-thalassemia, and normal cases was 67.87%, 19.68%, and 12.45%, respectively. Significant differences in almost all the hematological parameters (HbF, HbA, Hb, HCT, MCV, MCH, MCHC, RDW, and NBRCs) were observed in three groups (P < 0.001, except for RBC, P = 0.446). These differences were also observed in four α-thalassemia subgroups (P < 0.001) and were associated with the number of defected genes. Similarly, in five β-thalassemia genotypes, HbF, HbA, RBC, MCV, MCH and NBRCs were presented differently (P < 0.05). Additionally, the trends in RBC, Hb, and HCT changes in three α-thalassemia subgroups (silent carrier, trait, and major) and β⁺/β⁺ fetuses' MCV, MCH, and RDW levels with gestation age were opposite to those of normal fetuses. We compared the distribution of hematological parameters in fetuses affected by most genotypes of thalassemia, as well as their trends in relation to gestational age for the first time, which is a good reference for future studies and prenatal diagnostic practices. The investigated hematological parameters are also valuable in diagnosing and differentiating thalassemia.

Predictive Prenatal Diagnosis for Infantile-onset Inflammatory Bowel Disease Because of Interleukin-10 Signalling Defects

OBJECTIVES

Advances in genetic technologies provide opportunities for patient care and ethical challenges. Clinical care of patients with rare Mendelian disorders is often at the forefront of those developments. Whereas in classical polygenic inflammatory bowel disease (IBD), the predictive value of genetic variants is very low, predictive prenatal genetic diagnosis can inform families at high risk of severe genetic disorders. Patients with IL-10 signalling defects because of pathogenic variants in IL10RA, Il10RB, and IL10 develop severe infantile onset inflammatory bowel disease that is completely penetrant and has a high morbidity and substantial mortality despite treatment.

METHODS

We performed a survey among tertiary specialist paediatric centers of 10 countries on the utilization of predictive prenatal genetic diagnosis in IL-10 signalling defects. We retrospectively report prenatal genetics in a series of 8 families.

RESULTS

International variation in legislation, guidelines, expert opinion, as well as cultural and religious background of families and clinicians results in variable utilization of preimplantation and prenatal genetic testing for IL-10 signalling defects. Eleven referrals for prenatal diagnosis for IL-10 signalling defects were identified across 4 countries. We report on 8 families who underwent prenatal preimplantation monogenic testing after in vitro fertilization (n = 2) and/or by amniocentesis/chorion villus sampling (n = 6). A genetic diagnosis was established in 1 foetus and excluded in 7 foetuses (all IL10RA variants).

CONCLUSIONS

Prenatal genetic testing for IL10R-defects is feasible, yet the legal and ethical considerations are complex and controversial. In some countries, predictive genetics for IL-10-related signalling defects is entering clinical practice.

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.

Prenatal Diagnosis for Primary Immunodeficiency Disorders-An Overview of the Indian Scenario

Prenatal Diagnosis (PND) forms an important part of primary preventive management for families having a child affected with primary immunodeficiency. Although individually sparse, collectively this group of genetic disorders represents a significant burden of disease. This paper discusses the prenatal services available for affected families at various centers across the country and the challenges and ethical considerations associated with genetic counseling. Mutation detection in the index case and analysis of chorionic villous sampling or amniocentesis remain the preferred procedures for PND and phenotypic analysis of cordocentesis sample is reserved for families with well-characterized index case seeking PND in the latter part of the second trimester of pregnancy. A total of 112 families were provided PND services in the last decade and the presence of an affected fetus was confirmed in 32 families. Post-test genetic counseling enabled the affected families to make an informed decision about the current pregnancy.