Showing papers on "Amniocentesis published in 2019"

Risk of miscarriage following amniocentesis or chorionic villus sampling: systematic review of literature and updated meta-analysis

Abstract: Objectives: To estimate the procedure-related risks of miscarriage after amniocentesis and trans-abdominal chorionic villus sampling (CVS) based on a systematic review of the literature and an updated meta-analysis. Methods: A search of MEDLINE, EMBASE, and The Cochrane Library was carried out to identify studies reporting complications following CVS or amniocentesis. The inclusion criteria for the systematic review were studies reporting results from large controlled studies and those reporting data for pregnancy loss prior to 24 weeks’ gestation. Study authors were contacted when required to identify additional necessary data. Data for cases that had invasive procedure and controls groups were inputted in contingency tables and risk of miscarriage was estimated for each study. Summary statistics based on a fixed and random effects model were calculated after taking into account the weighting for each study included in the systematic review. Procedure-related risk of miscarriage was estimated as a weighted risk difference from the summary statistics for cases and controls. A subgroup analyses according to the similarity risk levels in the invasive testing and control groups was performed. Heterogeneity was assessed using Cochrane’s Q and I2 statistic. Egger Bias was estimated to assess reporting bias in published studies. Summary statistics for procedure-related risk of miscarriage were graphically represented in Forest plots. Results: The electronic search from the databases yielded 2,943 potential citations, from which, we selected 20 controlled studies for inclusion in the systematic review to estimate the procedure-related risk of miscarriage from invasive procedures. There were a total of 580 miscarriages from 63,273 amniocentesis procedures with a weighted risk of pregnancy loss of 0.91% (95%CI: 0.73 to 1.09). In the control group, there were 1,726 miscarriages in 330,469 pregnancies with a loss rate of 0.58% (95CI%: 0.47 to 0.70). The weighted procedure-related risk of miscarriage was 0.30% (95%CI: 0.11 to 0.49, I2=70.1%). There were a total of 163 miscarriages from 13,011 CVS procedures with a risk of pregnancy loss of 1.39% (95%CI: 0.76 to 2.02). In the control group, there were 1,946 miscarriages in 232,680 pregnancies with a loss rate of 1.23% (95CI%: 0.86 to 1.59). The weighted procedure-related risk of miscarriage following CVS was 0.20% (95%CI: -0.12 to 0.52, I2=51.9%). However, when only studies with similar risk profiles between the intervention and control groups were considered, the procedure related risk for amniocentesis became 0.03% (95%CI -0.08 to 0.14, I2=0%) and for CVS -0.38 (95% CI -1.12 to 0.36, I2=0%). Conclusion: The procedure-related risks of miscarriage following amniocentesis and CVS are lower than currently quoted to women. The risk appears to be negligible when these interventions are compared to control groups of the same risk profile.

Evidence that intra-amniotic infections are often the result of an ascending invasion - a molecular microbiological study.

Abstract: Background Microbial invasion of the amniotic cavity resulting in intra-amniotic infection is associated with obstetrical complications such as preterm labor with intact or ruptured membranes, cervical insufficiency, as well as clinical and histological chorioamnionitis. The most widely accepted pathway for intra-amniotic infection is the ascension of microorganisms from the lower genital tract. However, hematogenous dissemination of microorganisms from the oral cavity or intestine, retrograde seeding from the peritoneal cavity through the fallopian tubes, and introduction through invasive medical procedures have also been suggested as potential pathways for intra-amniotic infection. The primary reason that an ascending pathway is viewed as most common is that the microorganisms most often detected in the amniotic fluid are those that are typical inhabitants of the vagina. However, thus far, no studies have shown that microorganisms in the amniotic cavity are simultaneously present in the vagina of the woman from which they were isolated. The objective of the study was to determine the frequency with which microorganisms isolated from women with intra-amniotic infection are also present in the lower genital tract. Methods This was a cross-sectional study of women with intra-amniotic infection with intact membranes. Intra-amniotic infection was defined as a positive culture and elevated concentrations of interleukin-6 (IL-6) (>2.6 ng/mL) in amniotic fluid and/or acute histologic chorioamnionitis and funisitis. Microorganisms isolated from bacterial cultures of amniotic fluid were taxonomically identified through matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) and 16S ribosomal RNA (rRNA) gene sequencing. Vaginal swabs were obtained at the time of amniocentesis for the identification of microorganisms in the lower genital tract. The overall bacterial profiles of amniotic fluids and vaginal swabs were characterized through 16S rRNA gene sequencing. The bacterial profiles of vaginal swabs were interrogated for the presence of bacteria cultured from amniotic fluid and for the presence of prominent (>1% average relative abundance) operational taxonomic units (OTUs) within the overall 16S rRNA gene bacterial profiles of amniotic fluid. Results (1) A total of 75% (6/8) of women had bacteria cultured from their amniotic fluid that are typical residents of the vaginal ecosystem. (2) A total of 62.5% (5/8) of women with bacteria cultured from their amniotic fluid also had these bacteria present in their vagina. (3) The microorganisms cultured from amniotic fluid and also detected in the vagina were Ureaplasma urealyticum, Escherichia coli, and Streptococcus agalactiae. (4) 16S rRNA gene sequencing revealed that the amniotic fluid of women with intra-amniotic infection had bacterial profiles dominated by Sneathia, Ureaplasma, Prevotella, Lactobacillus, Escherichia, Gardnerella, Peptostreptococcus, Peptoniphilus, and Streptococcus, many of which had not been cultured from the amniotic fluid samples. (5) Seventy percent (7/10) of the prominent (>1% average relative abundance) OTUs found in amniotic fluid were also prominent in the vagina. Conclusion The majority of women with intra-amniotic infection had bacteria cultured from their amniotic fluid that were typical vaginal commensals, and these bacteria were detected within the vagina at the time of amniocentesis. Molecular microbiological interrogation of amniotic fluid from women with intra-amniotic infection revealed that the bacterial profiles of amniotic fluid were largely consistent with those of the vagina. These findings indicate that ascension from the lower genital tract is the primary pathway for intra-amniotic infection.

Prevention of maternal-fetal transmission of cytomegalovirus after primary maternal infection in the first trimester by biweekly hyperimmunoglobulin administration.

Abstract: OBJECTIVE To examine the efficacy of biweekly hyperimmunoglobulin (HIG) administration to prevent maternal-fetal transmission of cytomegalovirus (CMV) in women with primary first-trimester CMV infection. METHODS This was a prospective observational study of women with confirmed primary CMV infection in the first trimester who had the first HIG administration at or before 14 weeks' gestation. All women had biweekly HIG treatment until 20 weeks' gestation at a dose of 200 IU/kg of maternal body weight. Each subject underwent amniocentesis at least 6 weeks after first presentation at about 20 weeks. Primary outcome was maternal-fetal transmission at the time of amniocentesis, and secondary outcome was the frequency of congenital CMV infection at birth. The results were compared with a historic cohort of women with first-trimester CMV infection who did not undergo HIG treatment and who had amniocentesis at about 20 weeks. RESULTS Subjects were 40 pregnant women with a primary CMV infection, with a median gestational age at first presentation of 9.6 (range, 5.1-14.3) weeks. On average, HIG administration started at 11.1 weeks and continued until 16.6 weeks. Within this interval, HIG was administered between two and six times in each patient. While CMV immunoglobulin-G (IgG) monitoring showed periodic fluctuations during biweekly HIG administration cycles, high CMV-IgG avidity indices remained stable over the whole treatment period. Maternal-fetal transmission before amniocentesis occurred in only one of the 40 cases (2.5% (95% CI, 0-13.2%)). At delivery, two additional subjects were found to have had late-gestation transmission. Considering all three cases with maternal-fetal transmission, the transmission rate was 7.5% (95% CI, 1.6-20.4%) in our 40 cases. All infected neonates were asymptomatic at birth. The matched historical control group consisted of 108 pregnancies. Thirty-eight transmissions (35.2% (95% CI, 26.2-45.0%)) occurred in the control group, which was significantly higher (P < 0.0001) than the transmission rate in the HIG treatment group. CONCLUSION After a primary maternal CMV infection in the first trimester, biweekly HIG administration at a dose of 200 IU/kg prevents maternal-fetal transmission up to 20 weeks' gestation. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

DEGUM, ÖGUM, SGUM and FMF Germany Recommendations for the Implementation of First-Trimester Screening, Detailed Ultrasound, Cell-Free DNA Screening and Diagnostic Procedures

Abstract: First-trimester screening between 11 + 0 and 13 + 6 weeks with qualified prenatal counseling, detailed ultrasound, biochemical markers and maternal factors has become the basis for decisions about further examinations. It detects numerous structural and genetic anomalies. The inclusion of uterine artery Doppler and PlGF screens for preeclampsia and fetal growth restriction. Low-dose aspirin significantly reduces the prevalence of severe preterm eclampsia. Cut-off values define groups of high, intermediate and low probability. Prenatal counseling uses detection and false-positive rates to work out the individual need profile and the corresponding decision: no further diagnosis/screening – cell-free DNA screening – diagnostic procedure and genetic analysis. In pre-test counseling it must be recognized that the prevalence of trisomy 21, 18 or 13 is low in younger women, as in submicroscopic anomalies in every maternal age. Even with high specificities, the positive predictive values of screening tests for rare anomalies are low. In the general population trisomies and sex chromosome aneuploidies account for approximately 70 % of anomalies recognizable by conventional genetic analysis. Screen positive results of cfDNA tests have to be proven by diagnostic procedure and genetic diagnosis. In cases of inconclusive results a higher rate of genetic anomalies is detected. Procedure-related fetal loss rates after chorionic biopsy and amniocentesis performed by experts are lower than 1 to 2 in 1000. Counseling should include the possible detection of submicroscopic anomalies by comparative genomic hybridization (array-CGH). At present, existing studies about screening for microdeletions and duplications do not provide reliable data to calculate sensitivities, false-positive rates and positive predictive values.

Recent trends in prenatal genetic screening and testing.

Abstract: Prenatal testing in recent years has been moving toward non-invasive methods to determine the fetal risk for genetic disorders without incurring the risk of miscarriage. Rapid progress of modern high-throughput molecular technologies along with the discovery of cell-free fetal DNA in maternal plasma led to novel screening methods for fetal chromosomal aneuploidies. Such tests are referred to as non-invasive prenatal tests (NIPTs), non-invasive prenatal screening, or prenatal cell-free DNA screening. Owing to many advantages, the adoption of NIPT in routine clinical practice was very rapid and global. As an example, NIPT has recently become a standard screening procedure for all pregnant women in the Netherlands. On the other hand, invasive sampling procedures remain important, especially for their diagnostic value in the confirmation of NIPT-positive findings and the detection of Mendelian disorders. In this review, we focus on current trends in the field of NIPT and discuss their benefits, drawbacks, and consequences in regard to routine diagnostics.

Validation Studies for Single Circulating Trophoblast Genetic Testing as a Form of Noninvasive Prenatal Diagnosis.

Abstract: It has long been appreciated that genetic analysis of fetal or trophoblast cells in maternal blood could revolutionize prenatal diagnosis. We implemented a protocol for single circulating trophoblast (SCT) testing using positive selection by magnetic-activated cell sorting and single-cell low-coverage whole-genome sequencing to detect fetal aneuploidies and copy-number variants (CNVs) at ∼1 Mb resolution. In 95 validation cases, we identified on average 0.20 putative trophoblasts/mL, of which 55% were of high quality and scorable for both aneuploidy and CNVs. We emphasize the importance of analyzing individual cells because some cells are apoptotic, in S-phase, or otherwise of poor quality. When two or more high-quality trophoblast cells were available for singleton pregnancies, there was complete concordance between all trophoblasts unless there was evidence of confined placental mosaicism. SCT results were highly concordant with available clinical data from chorionic villus sampling (CVS) or amniocentesis procedures. Although determining the exact sensitivity and specificity will require more data, this study further supports the potential for SCT testing to become a diagnostic prenatal test.

Artificial intelligence and amniotic fluid multiomics: prediction of perinatal outcome in asymptomatic women with short cervix.

Abstract: OBJECTIVE To evaluate the application of artificial intelligence (AI), i.e. deep learning and other machine-learning techniques, to amniotic fluid (AF) metabolomics and proteomics, alone and in combination with sonographic, clinical and demographic factors, in the prediction of perinatal outcome in asymptomatic pregnant women with short cervical length (CL). METHODS AF samples, which had been obtained in the second trimester from asymptomatic women with short CL (< 15 mm) identified on transvaginal ultrasound, were analyzed. CL, funneling and the presence of AF 'sludge' were assessed in all cases close to the time of amniocentesis. A combination of liquid chromatography coupled with mass spectrometry and proton nuclear magnetic resonance spectroscopy-based metabolomics, as well as targeted proteomics analysis, including chemokines, cytokines and growth factors, was performed on the AF samples. To determine the robustness of the markers, we used six different machine-learning techniques, including deep learning, to predict preterm delivery < 34 weeks, latency period prior to delivery < 28 days after amniocentesis and requirement for admission to a neonatal intensive care unit (NICU). Omics biomarkers were evaluated alone and in combination with standard sonographic, clinical and demographic factors to predict outcome. Predictive accuracy was assessed using the area under the receiver-operating characteristics curve (AUC) with 95% CI, sensitivity and specificity. RESULTS Of the 32 patients included in the study, complete omics, demographic and clinical data and outcome information were available for 26. Of these, 11 (42.3%) patients delivered ≥ 34 weeks, while 15 (57.7%) delivered < 34 weeks. There was no statistically significant difference in CL between these two groups (mean ± SD, 11.2 ± 4.4 mm vs 8.9 ± 5.3 mm, P = 0.31). Using combined omics, demographic and clinical data, deep learning displayed good to excellent performance, with an AUC (95% CI) of 0.890 (0.810-0.970) for delivery < 34 weeks' gestation, 0.890 (0.790-0.990) for delivery < 28 days post-amniocentesis and 0.792 (0.689-0.894) for NICU admission. These values were higher overall than for the other five machine-learning methods, although each individual machine-learning technique yielded statistically significant prediction of the different perinatal outcomes. CONCLUSIONS This is the first study to report use of AI with AF proteomics and metabolomics and ultrasound assessment in pregnancy. Machine learning, particularly deep learning, achieved good to excellent prediction of perinatal outcome in asymptomatic pregnant women with short CL in the second trimester. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

The earlier the gestational age, the greater the intensity of the intra-amniotic inflammatory response in women with preterm premature rupture of membranes and amniotic fluid infection by Ureaplasma species.

Abstract: Objectives To determine the relationship between the intensity of the intra-amniotic inflammatory response and the gestational age at the time of diagnosis in cases with preterm premature rupture of membranes (PROM) and intra-amniotic infection caused by Ureaplasma spp. Methods A retrospective cohort study was conducted which included 71 women with preterm PROM and a positive amniotic fluid culture with Ureaplasma spp. Women with mixed intra-amniotic infections were excluded. The study population was classified into three groups according to gestational age: group 1, <26 weeks (extreme preterm PROM, n = 17); group 2, 26.0-33.9 weeks (moderate preterm PROM, n = 39); group 3, 34.0-36.9 weeks (late preterm PROM, n = 15). The intensity of the intra-amniotic and maternal inflammatory response was compared among the three groups. The intensity of the intra-amniotic inflammatory response was assessed by the concentration of amniotic fluid matrix metalloproteinase-8 (MMP-8) and white blood cell (WBC) count. The maternal inflammatory response was assessed by the concentration of C-reactive protein (CRP) and WBC count in maternal blood at the time of amniocentesis. Results (1) The median values of amniotic fluid MMP-8 concentration and WBC count were the highest in the extreme preterm PROM group and the lowest in the late preterm PROM group (P < 0.001 and P = 0.01, respectively); (2) the intensity of the maternal inflammatory response measured by maternal blood WBC count and CRP concentration was not significantly associated with gestational age at the time of diagnosis. Conclusion The earlier the gestational age at the time of PROM, the higher the intensity of the intra-amniotic inflammatory response in women with preterm PROM and intra-amniotic infection caused by Ureaplasma spp.

Procedure-related risk of miscarriage following chorionic villus sampling and amniocentesis.

Abstract: Objectives To estimate the procedure-related risks of miscarriage following chorionic villus sampling (CVS) and amniocentesis in a large unselected screened population, and to determine whether these risks are consistent with those reported in systematic reviews and meta-analyses. Methods This was a retrospective cohort study carried out on data obtained from a large fetal medicine unit in the UK between January 2009 and May 2018. We included all women with singleton pregnancy who booked for pregnancy care at our unit before 20 weeks' gestation, after excluding those with multiple pregnancy, major fetal defect, pregnancy termination and loss to follow-up. We estimated the risk of miscarriage in women who underwent a CVS or amniocentesis as well as in those who did not have an invasive procedure. The procedure-related risk of miscarriage was estimated as risk difference (95% CI) between the two groups. Univariate and multivariate regression analyses were used to derive odds ratios (95% CI) and determine which maternal and pregnancy characteristics provided a significant contribution in the prediction of miscarriage and whether CVS or amniocentesis provided a significant independent contribution. Results During the study period, 45 120 singleton pregnancies were booked for pregnancy care at our hospital, of which 1546 had an invasive procedure. We excluded 1429 (3.2%) pregnancies due to fetal defects, termination of pregnancy or missing outcomes. Of the 43 691 pregnancies included in the study population, 861 underwent CVS and 375 amniocentesis. In pregnancies that underwent CVS, the risk of miscarriage was 1.5% (13/861), compared with 1.2% (476/39 152) in pregnancies that had first-trimester combined screening and did not have an invasive procedure (P = 0.437). In pregnancies that underwent an amniocentesis, the risk of miscarriage was 0.8% (3/375), compared with 1.2% (491/42 463) in those that did not undergo an invasive procedure (P = 0.520). Univariate and multivariate regression analysis demonstrated that there was no significant contribution in the prediction of the risk of miscarriage from CVS (P = 0.399 and P = 0.592, respectively) or amniocentesis (P = 0.543 and P = 0.550, respectively). The risk of procedure-related loss attributed to CVS was 0.29% (95% CI, -0.53 to 1.12%) and that following amniocentesis was -0.36% (95% CI, -1.26 to 0.55%), which was not significantly different from the risk in women who did not have any procedure. Conclusions The procedure-related risks of miscarriage following CVS and amniocentesis in our study are considerably lower than those currently quoted and are consistent with the estimates of such risks reported by systematic reviews and meta-analyses. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Prevention and treatment of fetal cytomegalovirus infection with cytomegalovirus hyperimmune globulin: a multicenter study in Madrid.

Abstract: Introduction: Cytomegalovirus (CMV) is the leading cause of congenital infection worldwide. Data about the management of CMV infection in pregnant women are scarce, and treatment options are very limited. The aim of the study is to investigate the effectiveness of cytomegalovirus hyperimmune globulin (CMV-HIG) for the prevention and treatment of congenital CMV (cCMV) infection.Materials and methods: A retrospective observational study was conducted in three tertiary hospitals in Madrid. In the period 2009–2015, CMV-HIG (Cytotect® CP Biotest, Biotest) treatment was offered to all pregnant women with primary CMV infection and/or detection of CMV-DNA in amniotic fluid in participating centers. Women were divided into prevention and treatment groups (PG and TG, respectively). Those with primary CMV infection who had not undergone amniocentesis comprised the PG and received monthly CMV-HIG (100 UI/kg). If CMV-DNA was subsequently detected in amniotic fluid, one extra dose of CMV-HIG (200 UI/kg) was giv...

Testosterone measured from amniotic fluid and maternal plasma shows no significant association with directional asymmetry in newborn digit ratio (2D:4D).

Abstract: Foetal sex hormones can have powerful and far-reaching effects on later phenotype. However, obtaining accurate measurements is difficult for ethical reasons, and researchers often employ proxy variables to examine their effects. The relative length of the second and fourth fingers (digit ratio or 2D:4D) is frequently used for this purpose, as it is hypothesized to index variance in prenatal androgen and oestrogen exposure. Most studies employing this method examine digit ratio for the right hand (R2D:4D) and/or left hand (L2D:4D), though the mean value (M2D:4D) (i.e., the average of R2D:4D and L2D:4D) and directional asymmetry (D[R-L]) (i.e., R2D:4D minus L2D:4D) are also commonly used. As no published studies have examined M2D:4D or D[R-L] in relation to testosterone measured from amniotic fluid, we conducted a secondary analysis of data published by Ventura et al. The sample comprises 106 mothers from Portugal who underwent amniocentesis during the second trimester and their neonates. Newborn M2D:4D was negatively correlated with amniotic testosterone in females (P<0.05) but not in males; no significant association was observed between amniotic testosterone and D[R-L] in either sex. In addition, we examined testosterone measured from maternal circulation during the second trimester, and found that it was not a significant predictor of M2D:4D or D[R-L] in male or female infants. Further research should aim to measure the ratio of testosterone to oestradiol present in amniotic fluid and maternal plasma, to examine whether either is a predictor of digit ratio variables at different stages of postnatal development.

In Utero Amniotic Fluid Stem Cell Therapy Protects Against Myelomeningocele via Spinal Cord Coverage and Hepatocyte Growth Factor Secretion.

Abstract: Despite the poor prognosis associated with myelomeningocele (MMC), the options for prenatal treatments are still limited. Recently, fetal cellular therapy has become a new option for treating birth defects, although the therapeutic effects and mechanisms associated with such treatments remain unclear. The use of human amniotic fluid stem cells (hAFSCs) is ideal with respect to immunoreactivity and cell propagation. The prenatal diagnosis of MMC during early stages of pregnancy could allow for the ex vivo proliferation and modulation of autologous hAFSCs for use in utero stem cell therapy. Therefore, we investigated the therapeutic effects and mechanisms of hAFSCs-based treatment for fetal MMC. hAFSCs were isolated as CD117-positive cells from the amniotic fluid of 15- to 17-week pregnant women who underwent amniocentesis for prenatal diagnosis and consented to this study. Rat dams were exposed to retinoic acid to induce fetal MMC and were subsequently injected with hAFSCs in each amniotic cavity. We measured the exposed area of the spinal cord and hepatocyte growth factor (HGF) levels at the lesion. The exposed spinal area of the hAFSC-treated group was significantly smaller than that of the control group. Immunohistochemical analysis demonstrated a reduction in neuronal damage such as neurodegeneration and astrogliosis in the hAFSC-treated group. Additionally, in lesions of the hAFSC-treated group, HGF expression was upregulated and HGF-positive hAFSCs were identified, suggesting that these cells migrated to the lesion and secreted HGF to suppress neuronal damage and induce neurogenesis. Therefore, in utero hAFSC therapy could become a novel strategy for fetal MMC. Stem Cells Translational Medicine 2019;8:1170-1179.

Prenatal circulating microRNA signatures of foetal Down syndrome

Abstract: The altered expression pattern of miRNAs might potentially reflect anomalies related to foetal chromosomal aberrations. The aim of the study was to determine the expression level of miRNAs in plasma of pregnant women with foetal Down syndrome (DS). Out of 198 amniocentesis performed at 15-18 weeks of gestation, within a group of 12 patients with foetal DS and 12 patients with uncomplicated pregnancies, who delivered healthy newborns at term, we examined the expression level of 800 miRNAs using the NanoString technology. Our study revealed that there are 6 miRNAs were upregulated (hsa-miR-15a, hsa-let-7d, hsa-miR-142, hsa-miR-23a, hsa-miR-199, hsa-miR-191) and 7 were downregulated (hsa-miR-1290, hsa-miR-1915, hsa-miR30e, hsa-miR-1260, hsa-miR-483, hsa-miR-548, hsa-miR-590) in plasma samples of women with foetal DS syndrome. The genes regulated by identified miRNAs are involved in central nervous system development, congenital abnormalities and heart defects. The results of the present study yielded information on DS-specific miRNA expression signature, which can further help to design a panel of miRNAs as a non-invasive test for DS diagnosis. We believe that identified miRNAs may attend in the pathogenesis of DS and would potentially make a significant role for the future preventive therapies.

Traditional Prenatal Diagnosis: Past to Present.

Abstract: In the nearly 60 years since prenatal diagnosis for genetic disease was first offered, the field of prenatal diagnosis has progressed far past rudimentary uterine puncture to provide fetal material to assess gender and interpret risk. Concurrent with the improvements in invasive fetal sampling came technological advances in cytogenetics and molecular biology that widened both the scope of genetic disorders that could be diagnosed and also the resolution at which the human genome could be interrogated. Nowadays, routine blood work available to all pregnant women can determine the risk for common chromosome abnormalities; chorionic villus sampling (CVS) and amniocentesis can be used to diagnose nearly all conditions with a known genetic cause; and the genome and/or exome of a fetus with multiple anomalies can be sequenced in an attempt to determine the underlying etiology. This chapter will discuss some of the major advances in prenatal sampling and prenatal diagnostic laboratory techniques that have occurred over the past six decades.

Turner syndrome: New insights from prenatal genomics and transcriptomics

Abstract: In some parts of the world, prenatal screening using analysis of circulating cell-free (cf) DNA in the plasma of pregnant women has become part of routine prenatal care with limited professional guidelines and without significant input from the Turner syndrome community. In contrast to the very high positive predictive values (PPVs) achieved with cfDNA analysis for trisomy 21 (91% for high-risk and 82% for low-risk cases), the PPVs for monosomy X are much lower (~26%). This is because the maternal plasma sample contains both maternal cfDNA and placental DNA, which is a proxy for the fetal genome. Underlying biological mechanisms for false positive monosomy X screening results include confined placental mosaicism, co-twin demise, and maternal mosaicism. Somatic loss of a single X chromosome in the mother is a natural phenomenon that occurs with aging; this could explain many of the false positive cfDNA results. There is also increased awareness of women who have constitutional mosaicism for 45, X who are fertile. It is important to recognize that a positive cfDNA screen for 45, X does not mean that the fetus has Turner syndrome. A follow-up diagnostic test, either amniocentesis or neonatal karyotype/chromosome microarray, is recommended. Research studies on cell-free mRNA in second trimester amniotic fluid, which is almost exclusively fetal, demonstrate consistent dysregulation of genes involved in the hematologic, immune, and neurologic systems. This suggests that some of the pathophysiology of Turner syndrome occurs early in fetal life and presents novel opportunities for consideration of antenatal treatments.

Prenatally diagnosed developmental abnormalities of the central nervous system and genetic syndromes: A practical review

Abstract: Developmental brain abnormalities are complex and can be difficult to diagnose by prenatal imaging because of the ongoing growth and development of the brain throughout pregnancy and the limitations of ultrasound, often requiring fetal magnetic resonance imaging as an additional tool. As for all major structural congenital anomalies, amniocentesis with chromosomal microarray and a karyotype is the first-line recommended test for the genetic work-up of prenatally diagnosed central nervous system (CNS) abnormalities. Many CNS defects, especially neuronal migration defects affecting the cerebral and cerebellar cortex, are caused by single-gene mutations in a large number of different genes. Early data suggest that prenatal diagnostic exome sequencing for fetal CNS defects will have a high diagnostic yield, but interpretation of sequencing results can be complex. Yet a genetic diagnosis is important for prognosis prediction and recurrence risk counseling. The evaluation and management of such patients is best done in a multidisciplinary team approach. Here, we review general principles of the genetic work-up for fetuses with CNS defects and review categories of genetic causes of prenatally diagnosed CNS phenotypes.

Mechanisms of death in structurally normal stillbirths.

Abstract: Objectives To investigate mechanisms of in utero death in normally formed fetuses by measuring amniotic fluid (AF) biomarkers for hypoxia (erythropoietin [EPO]), myocardial damage (cardiac troponin I [cTnI]) and brain injury (glial fibrillary acidic protein [GFAP]), correlated with risk factors for fetal death and placental histopathology. Methods This retrospective, observational cohort study included intrauterine deaths with transabdominal amniocentesis prior to induction of labor. Women with a normal pregnancy and an indicated amniocentesis at term were randomly selected as controls. AF was assayed for EPO, cTnI and GFAP using commercial immunoassays. Placental histopathology was reviewed, and CD15-immunohistochemistry was used. Analyte concentrations >90th centile for controls were considered "raised". Raised AF EPO, AF cTnI and AF GFAP concentrations were considered evidence of hypoxia, myocardial and brain injury, respectively. Results There were 60 cases and 60 controls. Hypoxia was present in 88% (53/60), myocardial damage in 70% (42/60) and brain injury in 45% (27/60) of fetal deaths. Hypoxic fetuses had evidence of myocardial injury, brain injury or both in 77% (41/53), 49% (26/53) and 13% (7/53) of cases, respectively. Histopathological evidence for placental dysfunction was found in 74% (43/58) of these cases. Conclusion Hypoxia, secondary to placental dysfunction, was found to be the mechanism of death in the majority of fetal deaths among structurally normal fetuses. Ninety-one percent of hypoxic fetal deaths sustained brain, myocardial or both brain and myocardial injuries in utero. Hypoxic myocardial injury was an attributable mechanism of death in 70% of the cases. Non-hypoxic cases may be caused by cardiac arrhythmia secondary to a cardiac conduction defect.

Mother-to-child transmission of hepatitis B virus after amniocentesis: A retrospective matched cohort study.

Abstract: Objective The objective of this study is to determine whether amniocentesis increases the risk of mother-to-child transmission (MTCT) of hepatitis B virus (HBV) and evaluate risk factors for MTCT. Methods One hundred forty-three hepatitis B surface antigen (HBsAg)-positive women with amniocentesis were enrolled into the amniocentesis group. Six hundred five nonamniocentesis cases were matched with amniocentesis cases based on maternal viral loads, antiviral therapy regimens, and delivery dates. MTCT of HBV was defined as HBsAg and/or DNA positivity in infants from birth to age 7 to 12 months. Results Mother-to-child transmission rate was significantly higher in HBsAg-positive women with amniocentesis than in those without amniocentesis (2.80% vs 0.50%; relative risk [RR], 5.64; 95% CI, 1.28-24.93). In the amniocentesis group, maternal HBV DNA more than or equal to 7.0 log10 IU/mL and hepatitis B e-antigen (HBeAg) positivity were associated with higher MTCT rates than maternal HBV DNA less than 7.0 log10 IU/mL (10.81% vs 0%, p = .004) and HBeAg negativity (8.16% vs 0%, p = .013), and antiviral therapy reduced MTCT rate from 14.3% to 0% (p = .554) when maternal HBV DNA was more than or equal to 7.0 log10 IU/mL. Conclusions Amniocentesis increases the risk of MTCT in women with hepatitis B, and maternal HBV DNA more than or equal to 7.0 log10 IU/mL and HBeAg positivity are risk factors for MTCT. Antiviral therapy may be effective to prevent MTCT after amniocentesis in highly viremic mothers.

The frequency and clinical significance of intra-amniotic inflammation in twin pregnancies with preterm labor and intact membranes.

Abstract: Objective: The objective of this study is to evaluate the frequency and clinical significance of intra-amniotic inflammation in twin pregnancies with preterm labor and intact membranes.Study design: Amniotic fluid (AF) was retrieved from both sacs in 90 twin gestations with preterm labor and intact membranes (gestational age between 20 and 34 6/7 weeks). Preterm labor was defined as the presence of painful regular uterine contractions, with a frequency of at least 2 every 10 min, requiring hospitalization. Fluid was cultured and assayed for matrix metalloproteinase-8. Intra-amniotic inflammation was defined as an AF matrix metalloproteinase-8 concentration >23 ng/mL.Results: The prevalence of intra-amniotic inflammation for at least 1 amniotic sac was 39% (35/90), while that of proven intra-amniotic infection for at least one amniotic sac was 10% (9/90). Intra-amniotic inflammation without proven microbial invasion of the amniotic cavity was found in 29% (26/90) of the cases. Intra-amniotic inflam...

Partial Hydatidiform Mole and Coexistent Live Fetus: A Case Report and Review of the Literature.

Abstract: Twin pregnancy of a hydatidiform mole with a coexistent live fetus is very rare, and complete molar pregnancy is involved in most cases. A partial molar pregnancy almost always ends in miscarriage due to a triploid fetus. Here, we report a case of a 32-year-old Chinese woman with ultrasound diagnosis of a partial molar pregnancy. Amniocentesis suggested mosaicism, but the fetus was morphologically normal. The woman chose to continue the pregnancy after fully understanding the risk. The infant was delivered prematurely, and the presence of a large single placenta with molar changes. The baby's peripheral blood chromosomes were diploid, and the pregnant woman had no serious complications. The diagnosis, management, and monitoring of this condition will remain challenging because of its rarity. Partial hydatidiform mole combined with pregnancy can result in delivering of a normal fetus and live birth under proper management.

Noninvasive Approaches to Prenatal Diagnosis: Historical Perspective and Future Directions

Abstract: The field of prenatal screening and diagnosis has undergone enormous progress over the past four decades. Most of this period has been characterized by gradual improvements in the technical and public health aspects of prenatal screening for Down syndrome. Compared to the direct analysis of fetal cells from amniocentesis or chorionic villus sampling, noninvasive approaches using maternal blood or ultrasound have the great advantage of posing no risk of miscarriage to the pregnancy. Recent advances in molecular genetics and DNA sequencing have revolutionized both the accuracy and the range of noninvasive testing for genetic abnormalities using cell-free DNA in maternal plasma. Many of these advances have already been incorporated into clinical care, including diagnosis of fetal blood group and aneuploidy screening. The accelerated pace of these recent developments is creating not just technical and logistical challenges, but is also magnifying the ethical and public policy issues traditionally associated with this field.

Cervical and Amniotic Fluid Matrix Metalloproteinase-8 and Interleukin-6 Concentrations in Preterm Pregnancies with or without Preterm Premature Rupture of Membranes.

Abstract: Introduction Intra-amniotic inflammation is defined by elevated inflammatory biomarkers in the amniotic fluid (AF), either due to microbial invasion of the amniotic cavity (MIAC) or sterile inflammation. Amniocentesis being an invasive procedure, we wanted to investigate whether elevated matrix metalloproteinase-8 (MMP-8) or interleukin-6 (IL-6) concentrations could be detected from cervical fluid samples. Materials and methods This prospective study included 67 women with singleton nondiabetic pregnancies with or without preterm premature rupture of membranes (PPROM) between 22+0 and 37+0 weeks of gestation. Simultaneous AF and cervical samples were obtained. Results In women without PPROM, cervical MMP-8 concentrations correlated with AF MMP-8 concentrations (rS = 0.466, p = 0.002), but cervical IL-6 did not correlate with AF IL-6 (rS = 0.277, p = 0.076). In PPROM cases no correlations were found. Women with MIAC had higher concentrations of AF MMP-8 and AF IL-6 compared to women without MIAC regardless of membrane status. However, only women without PPROM had higher concentrations of cervical MMP-8 in proven MIAC. Conclusion In women without PPROM, cervical MMP-8 concentration reflects the magnitude of AF MMP-8, thus potentially guiding the selection of patients benefitting from amniocentesis.

LB20. Valacyclovir to Prevent Vertical Transmission of Cytomegalovirus After Maternal Primary Infection During Pregnancy

Abstract: Background Cytomegalovirus (CMV) is the most common cause of congenital infection in humans. The highest risk of fetal injury follows a maternal primary infection early in pregnancy. Despite the potential for severe fetal injury, to date there are no proven means to prevent viral transmission. Valacyclovir is an antiviral drug proven effective in decreasing the risk for CMV infection among transplant recipients. Valacyclovir is safe for use in pregnancy, and concentrates in the amniotic fluid without accumulating. A dose of 8 g/day creates therapeutic drug levels in the amniotic fluid and fetal blood.

Cell-free nucleic acids in prenatal diagnosis and pregnancy-associated diseases.

Abstract: There is a great effort to find out the biological role of cell-free nucleic acids (cfNAs). They are considered very promising targets in the diagnosis of genetic diseases. Non-invasive sampling (liquid biopsy) has recently become a very popular method, and new molecular biological techniques have been developed for these types of samples. Application of next-generation sequencing (NGS) and massively parallel sequencing (MPS) is spreading fast. These are the part of the arsenal of the modern prenatal genetic diagnostic laboratories by now. Cell-free DNA based noninvasive prenatal testing accounts for more than half of the prenatal genetic tests performed, it is gradually replacing the invasive amniocentesis or chorionic villus sample-based diagnostics. Besides that, new non-coding RNAs are taking more attention: microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) are in the focus of the clinical research to detect the most common pregnancy-associated diseases, like preeclampsia, fetal growth restriction, congenital heart diseases and gestational diabetes. The research is at advanced stage on the use of microRNAs, while lncRNAs and circRNAs are still promising targets. In this review, comprehensive information is given about the recent developments on this field.