Role of late amniocentesis in the era of modern genomic technologies

Amniocentesis in pregnancies at or beyond 24 weeks: an international multicenter study

BACKGROUND

Amniocentesis for genetic diagnosis is most commonly done between 15 and 22 weeks of gestation but can be performed at later gestational ages. The safety and genetic diagnostic accuracy of amniocentesis have been well-established through numerous large-scale multicenter studies for procedures before 24 weeks, but comprehensive data on late amniocentesis remain sparse.

OBJECTIVE

To evaluate the indications, diagnostic yield, safety, and maternal and fetal outcomes associated with amniocentesis performed at or beyond 24 weeks of gestation.

STUDY DESIGN

We conducted an international multicenter retrospective cohort study examining pregnant individuals who underwent amniocentesis for prenatal diagnostic testing at gestational ages between 24w0d and 36w6d. The study, spanning from 2011 to 2022, involved 9 referral centers. We included singleton or twin pregnancies with documented outcomes, excluding cases where other invasive procedures were performed during pregnancy or if amniocentesis was conducted for obstetric indications. We analyzed indications for late amniocentesis, types of genetic tests performed, their results, and the diagnostic yield, along with pregnancy outcomes and postprocedure complications.

RESULTS

Of the 752 pregnant individuals included in our study, late amniocentesis was primarily performed for the prenatal diagnosis of structural anomalies (91.6%), followed by suspected fetal infection (2.3%) and high-risk findings from cell-free DNA screening (1.9%). The median gestational age at the time of the procedure was 28w5d, and 98.3% of pregnant individuals received results of genetic testing before birth or pregnancy termination. The diagnostic yield was 22.9%, and a diagnosis was made 2.4 times more often for fetuses with anomalies in multiple organ systems (36.4%) compared to those with anomalies in a single organ system (15.3%). Additionally, the diagnostic yield varied depending on the specific organ system involved, with the highest yield for musculoskeletal anomalies (36.7%) and hydrops fetalis (36.4%) when a single organ system or entity was affected. The most prevalent genetic diagnoses were aneuploidies (46.8%), followed by copy number variants (26.3%) and monogenic disorders (22.2%). The median gestational age at delivery was 38w3d, with an average of 59 days between the procedure and delivery date. The overall complication rate within 2 weeks postprocedure was 1.2%. We found no significant difference in the rate of preterm delivery between pregnant individuals undergoing amniocentesis between 24 and 28 weeks and those between 28 and 32 weeks, reinforcing the procedure's safety across these gestational periods.

CONCLUSION

Late amniocentesis, at or after 24 weeks of gestation, especially for pregnancies complicated by multiple congenital anomalies, has a high diagnostic yield and a low complication rate, underscoring its clinical utility. It provides pregnant individuals and their providers with a comprehensive diagnostic evaluation and results before delivery, enabling informed counseling and optimized perinatal and neonatal care planning.

Exploring the safety and diagnostic utility of amniocentesis after 24 weeks of gestation: a retrospective analysis

OBJECTIVES

This study aims to describe the indications, complications, yield, and safety of amniocentesis beyond 24 weeks for prenatal diagnostic procedures along with the associated maternal and fetal outcomes.

METHODS

A retrospective analysis was conducted on 60 pregnant women (with 61 fetuses) who underwent amniocentesis at or beyond 24 weeks from March 2021 to June 2023 at a tertiary care referral center. Data was collected from medical records and individual patient followups. Descriptive data was collected on patient demographics, amniocentesis indications, and the test results. The other outcomes analyzed were the procedure-related complications and pregnancy outcomes.

RESULTS

The mean gestational age at time of the procedure was 254/7 (241/7-331/7). The most common indication for late amniocentesis was abnormal sonographic findings (44/61, 72.13 %), with structural anomalies being the commonest (21/61, 34.44 %). There were no complications related to the procedure. Of the 60 women, 88.3 % (53/60) continued their pregnancies, while 11.66 % (7/60) opted for termination of pregnancy, and two patients had intrauterine fetal demise (2/61, 3.27 %). Genetic testing revealed abnormalities in 6.55 % (4/61) of cases. Of the 51 pregnancies, 39 delivered vaginally (76.47 %; 39/51) and 12 (23.52 %; 12/51) required caesarean sections. There were five neonatal and infant deaths due to heart defects (2), metabolic syndrome, congenital diaphragmatic hernia, and non-immune hydrops, respectively.

CONCLUSIONS

Amniocentesis, done at a later gestation, is a safe and an effective tool for prenatal diagnosis and provides an opportunity to make a genetic diagnosis and further counseling.

Perceived Impact of Healthcare Relationships and Interactions on Parental Experiences of Prenatal Diagnosis and Termination of Pregnancy for Foetal Anomaly on the Island of Ireland

OBJECTIVE

The aim of this study was to explore parents' experiences of their relationships and interactions with healthcare professionals (HCPs) during care related to prenatal diagnosis and termination of pregnancy for foetal anomaly (TOPFA).

METHODS

A qualitative approach was used. Participants included 33 parents (23 women and 10 men) from Northern Ireland (n = 11) and Ireland (n = 22) who had a TOPFA. Data collection methods included semi-structured interviews and written narrative accounts. Data were analysed using thematic analysis.

RESULTS

Findings confirmed that TOPFA was a traumatic, life-altering experience for parents, impacting their health and well-being. The actions, behaviours and words of HCPs impacted how parents perceived and interpreted their healthcare experiences and their access to services and supports. In relation to this, five themes are presented: (1) the importance of compassionate and non-judgemental care, (2) the value of effective information and communication, (3) the desire for compassionate care for baby and facilitation of memory making, (4) the need for continuity of care and (5) parents' experiences of healthcare relationships during times of legislative change.

CONCLUSION

This research reveals the important role HCPs play in helping parents cope with prenatal testing and TOPFA. Parents who had a positive relationship with an HCP, in which information was communicated effectively and compassionate and non-judgmental care was provided, felt more supported and more able to accept and adapt to their loss.

PATIENT AND PUBLIC CONTRIBUTION

An advisory group composed of parents who had experienced TOPFA and HCPs with experience in caring for such families were involved in the study from the outset, contributing to the design and development of data collection materials, interpretation of the findings and design of dissemination materials.

Interface-Stabilized Fiber Sensor for Real-Time Monitoring of Amniotic Fluid During Pregnancy

Diseases in pregnancy endanger millions of fetuses worldwide every year. The onset of these diseases can be early warned by the dynamic abnormalities of biochemicals in amniotic fluid, thus requiring real-time monitoring. However, when continuously penetrated by detection devices, the amnion is prone to loss of robustness and rupture, which is difficult to regenerate. Here, an interface-stabilized fiber sensor is presented for real-time monitoring of biochemical dynamics in amniotic fluid during pregnancy. The sensor is seamlessly integrated into the amnion through tissue adhesion, amniotic regeneration, and uniform stress distribution, posing no risk to the amniotic fluid environment. The sensor demonstrates a response performance of less than 0.3% fluctuation under complex dynamic conditions and an accuracy of more than 98% from the second to the third trimester. By applying it to early warning of diseases such as intrauterine hypoxia, intrauterine infection, and fetal growth restriction, fetal survival increases to 95% with timely intervention.

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.

Late amniocentesis: better late than never? A single referral centre experience

INTRODUCTION

Several congenital abnormalities present late in pregnancy necessitating invasive testing to rule out genetic/infectious causes at late gestation. Not many studies have described the indications/safety of a late gestation amniocentesis.

METHODS

All records of amniocentesis performed beyond 24 weeks were reviewed and evaluated for indications, positive yield and complications.

RESULTS

About 187 women had an amniocentesis after 24 weeks for various indications with CNS abnormalities being the commonest. The total yield of positive findings was 14.60% (22/150; excluding 2 VOUS). CNS, multiple system involvement and skeletal system anormalities yielded maximum results. About 32.05% abnormalities could have potentially been detected at the time of a routine anomaly scan. Amongst all the deliveries, 2.1%  delivered spontaneously within a week of the procedure and about 5.4% delivered spontaneously within a month of the procedure.

CONCLUSION

The study emphasises the need for additional accreditation (FMF, ISUOG) of sonographers to ensure the detection of anomalies at the routine 18-20 weeks scan. Inspite of a normal mid-trimester scan, central nervous system and gastrointestinal abnormalities presented more commonly after 24 weeks. The high positive yield in our study highlights the importance of testing even in late pregnancy beyond the legal age of termination. The test could clearly stratify the pregnancies with a poor outcome whilst reassuring the others. The procedure itself did not lead to a neonatal death due to prematurity.

Receiving uncertain results from prenatal chromosomal microarray analysis: Women's decisions on continuation or termination of pregnancy

BACKGROUND

Chromosomal microarray analysis (CMA) may detect variants of uncertain clinical significance (VUS) and susceptibility loci (SL) with incomplete penetrance for neurodevelopmental disorders. This qualitative study provides empirical data on women's experiences with receiving such findings in pregnancy and their decisions regarding continuation or termination of the pregnancy.

METHODS

Semi-structured interviews were conducted with women who received a VUS and/or SL from prenatal CMA in the last 2-4 years and were analyzed using Grounded Theory.

RESULTS

The vast majority of women recalled being stressed by the findings. All women sought further advice and information to be able to decide whether to continue or terminate their pregnancy. The three pregnancies that were terminated have in common a de novo SL with a 10%-20% penetrance. Similar reasoning (coping with uncertainty, the quest for a perfect child, and a chance for recurrence in future pregnancies) led different women to contradicting conclusions regarding their pregnancies. All women felt satisfied with their decisions.

CONCLUSION

Although uncertain/probabilistic information commonly involves a psychological burden, it may also be perceived as valuable and actionable. Pre-test parental choice regarding the disclosure of such information could allow personalized utilization of advanced genomic tests in pregnancy.

Drug exposure during pregnancy: Current understanding and approaches to measure maternal-fetal drug exposure

Prescription drug use is prevalent during pregnancy, yet there is limited knowledge about maternal-fetal safety and efficacy of this drug use because pregnant individuals have historically been excluded from clinical trials. Underrepresentation has resulted in a lack of data available to estimate or predict fetal drug exposure. Approaches to study fetal drug pharmacology are limited and must be evaluated for feasibility and accuracy. Anatomic and physiological changes throughout pregnancy fluctuate based on gestational age and can affect drug pharmacokinetics (PK) for both mother and fetus. Drug concentrations have been studied throughout different stages of gestation and at or following delivery in tissue and fluid biospecimens. Sampling amniotic fluid, umbilical cord blood, placental tissue, meconium, umbilical cord tissue, and neonatal hair present surrogate options to quantify and characterize fetal drug exposure. These sampling methods can be applied to all therapeutics including small molecule drugs, large molecule drugs, conjugated nanoparticles, and chemical exposures. Alternative approaches to determine PK have been explored, including physiologically based PK modeling, in vitro methods, and traditional animal models. These alternative approaches along with convenience sampling of tissue or fluid biospecimens can address challenges in studying maternal-fetal pharmacology. In this narrative review, we 1) present an overview of the current understanding of maternal-fetal drug exposure; 2) discuss biospecimen-guided sampling design and methods for measuring fetal drug concentrations throughout gestation; and 3) propose methods for advancing pharmacology research in the maternal-fetal population.

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.

Termination of pregnancy for fetal anomaly: a systematic review of the healthcare experiences and needs of parents

BACKGROUND

Improved technology and advances in clinical testing have resulted in increased detection rates of congenital anomalies during pregnancy, resulting in more parents being confronted with the possibility of terminating a pregnancy for this reason. There is a large body of research on the psychological experience and impact of terminating a pregnancy for fetal anomaly. However, there remains a lack of evidence on the holistic healthcare experience of parents in this situation. To develop a comprehensive understanding of the healthcare experiences and needs of parents, this systematic review sought to summarise and appraise the literature on parents' experiences following a termination of pregnancy for fetal anomaly.

REVIEW QUESTION

What are the healthcare experiences and needs of parents who undergo a termination of pregnancy following an antenatal diagnosis of a fetal anomaly?

METHODS

A systematic review was undertaken with searches completed across six multi-disciplinary electronic databases (Medline, Embase, PsycINFO, CINAHL, Web of Science, and Cochrane). Eligible articles were qualitative, quantitative or mixed methods studies, published between January 2010 and August 2021, reporting the results of primary data on the healthcare experiences or healthcare needs in relation to termination of pregnancy for fetal anomaly for either, or both parents. Findings were synthesised using Thematic Analysis.

RESULTS

A total of 30 articles were selected for inclusion in this review of which 24 were qualitative, five quantitative and one mixed-methods. Five overarching themes emerged from the synthesis of findings: (1) Contextual impact on access to and perception of care, (2) Organisation of care, (3) Information to inform decision making, (4) Compassionate care, and (5) Partner experience.

CONCLUSION

Compassionate healthcare professionals who provide non-judgemental and sensitive care can impact positively on parents' satisfaction with the care they receive. A well organised and co-ordinated healthcare system is needed to provide an effective and high-quality service.

TRIAL REGISTRATION

PROSPERO registration number: CRD42020175970 .

Individualized treatment of preterm premature rupture of membranes to prolong the latency period, reduce the rate of preterm birth, and improve neonatal outcomes

BACKGROUND

Preterm premature rupture of membranes complicates approximately 3% of pregnancies. Currently, in the absence of chorioamnionitis or placental abruption, expectant management, including antenatal steroids for lung maturation and prophylactic antibiotic treatment, is recommended. The benefits of individualized management have not been adequately explored.

OBJECTIVE

This study aimed to compare the impact of 2 different management strategies of preterm premature rupture of membranes in 2 tertiary obstetrical centers on latency of >7 days, latency to birth, chorioamnionitis, funisitis, and short-term adverse maternal and neonatal outcomes.

STUDY DESIGN

This was a multicenter retrospective study of women with singleton pregnancies with preterm premature rupture of membranes from 23 0/7 to 33 6/7 weeks of gestation between 2014 and 2018 and undelivered within 24 hours after hospital admission managed at Sunnybrook Health Sciences Center, Toronto, Canada (standard management group), and BCNatal (Hospital Clínic of Barcelona and Hospital Sant Joan de Déu Barcelona), Barcelona, Spain (individualized management group), following local protocols. The standard management group received similar management for all patients, which included a standard antibiotic regimen and routine maternal and fetal surveillance, whereas the individualized management group received personalized management on the basis of amniocentesis at hospital admission (if possible), to rule out microbial invasion of the amniotic cavity and targeted treatment. The exclusion criteria were cervical dilatation >2 cm, active labor, contraindications to expectant management (acute chorioamnionitis, placental abruption, or abnormal fetal tracing), and major fetal anomalies. The primary outcome was latency of >7 days, and the secondary outcomes included latency to birth, chorioamnionitis, and short-term adverse maternal and neonatal outcomes. Statistical comparisons between groups were conducted with propensity score weighting.

RESULTS

A total of 513 pregnancies with preterm premature rupture of membranes were included in this study: 324 patients received standard management, and 189 patients received individualized management, wherein amniocentesis was performed in 112 cases (59.3%). After propensity score weighting, patients receiving individualized management had a higher latency of >7 days (76.0% vs 41.6%; P<.001) and latency to birth (18.1±14.7 vs 9.7±9.7 days; P<.001). Although a higher rate of clinical chorioamnionitis was suspected in the individualized management group than the standard group (34.5% vs 22.0%; P<.01), there was no difference between the groups in terms of histologic chorioamnionitis (67.2% vs 73.4%; P=.16), funisitis (57.6% vs 58.1%; P=.92), or composite infectious maternal outcomes (9.1% vs 7.9%; P=.64). Prolonged latency in the individualized management group was associated with a significant reduction of preterm birth at <32 weeks of gestation (72.1% vs 90.5%; P<.001), neonatal intensive care unit admission (75.6% vs 83.0%; P=.046), and neonatal respiratory support at 28 days of life (16.1% vs 26.1%; P<.01) compared with that in the standard management group. Moreover, prolonged latency was not associated with neonatal severe morbidity at discharge (survival without severe morbidity, 80.4% vs 73.5%; P=.09).

CONCLUSION

Individualized management of preterm premature rupture of membranes may prolong pregnancy and reduce preterm birth at <32 weeks of gestation, the need for neonatal support, and neonatal intensive care unit admissions, without an increase in histologic chorioamnionitis, funisitis, neonatal infection-related morbidity, and short-term adverse maternal and neonatal outcomes.

Antimicrobial prophylaxis post-amniocentesis procedures in cattle: A randomized controlled equivalence study

Amniocentesis is a routine procedure utilized on several species including human, equine, and bovine patients. Early assessment and discovery of new genetic traits in the cattle industry are highly desirable in order to accelerate genetic gain by shortening generational intervals. One of the main concerns from this procedure is the introduction of pathogenic bacterial contamination into the amniotic cavity thereby increasing the risks of spontaneous pregnancy losses post procedure. In this randomized controlled equivalence study, we have tested the effect of antimicrobial prophylaxis on the incidence of spontaneous abortions and contrasted it to untreated individuals post amniocentesis. On the treated group (n = 67) all heifers remained pregnant whereas 1 of the untreated group (n = 65) resulted in a spontaneous abortion during the study period. The latter represents 1.54% of pregnancy losses attributed to the risk associated to the amniocentesis procedure. However, the probability of inducing spontaneous abortion from the technique itself is not different to that of the contemporaneous population (n = 694) not undergoing amniocentesis viz., 1.59%. Following a two-tailed distribution, statistical analyses showed no significant differences across treatments (Fisher's exact test P = 0.49). The current prospective study indicates that performing amniocenteses on cattle have resulted in similar spontaneous pregnancy losses comparable to those of pregnant heifers without undergoing amniocentesis and regardless of antimicrobial use. In conclusion, prophylactic antimicrobials may not be applicable within the cattle amniocentesis framework.

Clinicians' attitudes towards parental choice in the era of advanced genomic tests in pregnancy

OBJECTIVE

Israel is one of the first countries to incorporate chromosomal microarray analysis into routine prenatal care. We explored attitudes of Israeli healthcare professionals (HCPs) towards the disclosure of challenging findings: variants of uncertain clinical significance (VUS), susceptibility loci (SL) for neurodevelopmental disorders and variants associated with adult-onset (AO) conditions. Particularly, we sought their views on providing parental choice regarding the disclosure of these findings.

METHODS

Twenty-nine in-depth interviews were conducted with genetic counselors (n = 19), medical geneticists (n = 4), medical geneticists that are trained in and practice fetal medicine (n = 3), and fetal medicine experts (n = 3).

RESULTS

Most participants (n = 24) supported parental choice regarding uncertain genetic information. Engaging parents in disclosure decisions allows avoidance from potentially anxiety-provoking information, practicing parental autonomy, and better preparation in cases where uncertain findings are identified. HCPs believed that given appropriate preparation, parents can make informed decisions. Four participants believed that disclosure should be based on professional judgment and one supported full-disclosure. Unlike VUS or SL, all interviewees agreed that in cases of medically actionable AO conditions, the benefit of disclosure outweighs the damage.

CONCLUSION

HCPs attitudes are largely in-line with the Israeli practice of involving parents in disclosure decisions regarding uncertain information. This may mitigate disclosure dilemmas and allow personalized disclosure based on parents' views.

Metabolic Profile and Neurogenic Potential of Human Amniotic Fluid Stem Cells From Normal vs. Fetus-Affected Gestations

Human amniotic fluid stem cells (hAFSCs) possess some characteristics with mesenchymal stem cells (MSCs) and embryonic stem cells and have a broader differentiation potential compared to MSCs derived from other sources. Although hAFSCs are widely researched, their analysis mainly involves stem cells (SCs) obtained from normal, fetus-unaffected gestations. However, in clinical settings, knowledge about hAFSCs from normal gestations could be poorly translational, as hAFSCs from healthy and fetus-diseased gestations may differ in their differentiation and metabolic potential. Therefore, a more thorough investigation of hAFSCs derived from pathological gestations would provide researchers with the knowledge about the general characteristics of these cells that could be valuable for further scientific investigations and possible future clinical applicability. The goal of this study was to look into the neurogenic and metabolic potential of hAFSCs derived from diseased fetuses, when gestations were concomitant with polyhydramnios and compare them to hAFSCs derived from normal fetuses. Results demonstrated that these cells are similar in gene expression levels of stemness markers (SOX2, NANOG, LIN28A, etc.). However, they differ in expression of CD13, CD73, CD90, and CD105, as flow cytometry analysis revealed higher expression in hAFSCs from unaffected gestations. Furthermore, hAFSCs from “Normal” and “Pathology” groups were different in oxidative phosphorylation rate, as well as level of ATP and reactive oxygen species production. Although the secretion of neurotrophic factors BDNF and VEGF was of comparable degree, as evaluated with enzyme-linked immunosorbent assay (ELISA) test, hAFSCs from normal gestations were found to be more prone to neurogenic differentiation, compared to hAFSCs from polyhydramnios. Furthermore, hAFSCs from polyhydramnios were distinguished by higher secretion of pro-inflammatory cytokine TNFα, which was significantly downregulated in differentiated cells. Overall, these observations show that hAFSCs from pathological gestations with polyhydramnios differ in metabolic and inflammatory status and also possess lower neurogenic potential compared to hAFSCs from normal gestations. Therefore, further in vitro and in vivo studies are necessary to dissect the potential of hAFSCs from polyhydramnios in stem cell-based therapies. Future studies should also search for strategies that could improve the characteristics of hAFSCs derived from diseased fetuses in order for those cells to be successfully applied for regenerative medicine purposes.

Chromosomal microarray analysis for pregnancies with abnormal maternal serum screening who undergo invasive prenatal testing

Recently, chromosomal microarray analysis (CMA) has been implemented as a first-tier test in pregnancies with ultrasound anomalies. However, its application for pregnancies with abnormal maternal serum screening (AMSS) only is not widespread. This study evaluated the value of CMA compared to traditional karyotyping in pregnancies with increased risk following first- or second-trimester maternal serum screening. Data from 3973 pregnancies with referral for invasive prenatal testing following AMSS were obtained from April 2016 to May 2020. Routine karyotyping was performed and single nucleotide polymorphism array was recommended. The foetuses were categorized according to the indications as AMSS only (group A) and AMSS with ultrasound anomalies (group B). CMA was performed on 713 prenatal samples. The proportion of women opting for CMA testing in both groups increased over the years. The incremental yield of clinically significant findings for pregnancies with high risk of screening results was similar to that for the foetuses with ultrasound soft markers (P > 0.05), but significantly lower than that for the foetuses with structural anomalies (P < 0.05). The total frequencies of variants of unknown significance in groups A and B showed no significant difference (P > 0.05). CMA should be performed for pregnant women undergoing prenatal invasive testing due to AMSS, especially with high-risk results, regardless of ultrasound findings.

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.

Procedure-to-delivery interval after late amniocentesis and the need for routine antenatal corticosteroids

OBJECTIVES

The aim of this study is to assess the procedure-to-delivery interval (PDI), the obstetric complications, and the early neonatal outcome in patients that did or did not receive glucocorticosteroids (GCSs) before third-trimester amniocentesis (TTA).

METHODS

A retrospectively analysis of 445 TTA procedures divided into two groups based on the administration (study group = 220 patients) or not (control group = 225 patients) of GCSs before TTA. The PDI was calculated for all patients. Obstetric and neonatal outcomes were compared between the groups.

RESULTS

The rate of procedure-associated complications was similar between the groups. The mean PDI was 47.2 ± 16.8 days. The overall incidence of preterm birth was 11.7%; 9% delivered between 34 and 37 weeks and 2.7% between 28 and 34 weeks. Only nine patients (2%) delivered within seven days following TTA. The incidence of respiratory distress syndrome in the study and control groups was 1.8% and 1.3%, p = .71, respectively. There were no significant differences in other neonatal outcomes in term and preterm deliveries between the study and control groups.

CONCLUSIONS

In the present study, the administration of glucocorticoids prior to TTA did not reduce the rates of neonatal complications, which was similar in both groups and not higher than the general population.

RASopathies: A significant cause of polyhydramnios?

OBJECTIVE

The aim of the study is to determine the prevalence of RASopathies in a polyhydramnios cohort selected by postnatal medical genetics evaluation.

METHODS

In this retrospective study, we reviewed 622 pregnancies with polyhydramnios seen at Lucile Packard Children's Hospital between 2008 and 2017. The findings from 131 cases evaluated by Medical Genetics were included in our final analysis. Genetic testing information was extracted to determine the rate of chromosomal or single gene conditions focusing on the RASopathies. Additional variables collected were: maternal characteristics, ultrasound findings, and the severity and timing of diagnosis of polyhydramnios.

RESULTS

Postnatal genetic testing or clinical examination identified a genetic disorder in 63 (48.1%) cases, more than half (n = 33) of which had a single gene condition. Postnatal testing revealed an underlying RASopathy in 15 (11.5%) cases. An underlying RASopathy was significantly associated with the severity and timing of polyhydramnios (p < 0.05).

CONCLUSION

Focusing on a selected cohort postnatally evaluated by Medical Genetics, our study identified a chromosomal or genetic disorder in almost half of pregnancies complicated by polyhydramnios. Specifically, an underlying RASopathy was found in 11.5% of cases with 13/15 of these cases having additional ultrasound findings.

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.

Information Women Choose to Receive About Prenatal Chromosomal Microarray Analysis

OBJECTIVE

To examine the choices of women with both high-risk and low-risk pregnancies who are undergoing prenatal chromosomal microarray analysis in a clinical setting regarding three challenging types of findings: variants of uncertain clinical significance, susceptibility loci for neurodevelopmental disorders, and copy number variants associated with risks for adult-onset conditions. We assessed whether women's choices were associated with indications for testing or with one-on-one pretest genetic counseling.

METHODS

In this cross-sectional study, medical records of women who underwent invasive prenatal chromosomal microarray analysis testing (N=1,070) at Hadassah Medical Center between June 2017 and February 2018 were examined for testing indications, choices regarding chromosomal microarray analysis findings, and type of pretest genetic counseling. Multivariable analyses to assess associations with testing indication and prior genetic counseling were carried out using logistic regression models.

RESULTS

In total, 56% of women (n=593) chose to be informed of all three types of findings and 20% (n=218) chose not to be informed of any of the findings beyond high-penetrance childhood-onset pathogenic findings. Variants of uncertain clinical significance as a single choice was the least-selected finding (2.5%, n=27). Low-risk pregnancies (ie, those with normal biochemical screening and fetal ultrasound examinations) were associated with increased interest in receiving genetic information about adult-onset conditions (adjusted odds ratio [aOR] 1.7; 95% CI 1.18-2.33) and susceptibility loci (aOR 1.5; 95% CI 1.08-2.10).

CONCLUSION

Women with both high-risk and low-risk pregnancies were generally more likely to choose to receive additional genetic information, albeit differences in preferences depend on testing indication and type of pretest counseling.