Telegenetics to provide comprehensive prenatal diagnosis.

Telehealth is an effective way to increase access to genetic services and can address several challenges, including geographic barriers, a shortage of interpreter services, and workforce issues, especially for prenatal diagnosis. The addition of prenatal telegenetics to current workflows shows promise in enhancing the delivery of genetic counseling and testing in prenatal care, providing accessibility, accuracy, patient satisfaction, and cost-effectiveness. Further research is needed to explore long-term patient outcomes and the evolving role of telehealth for prenatal diagnosis. Future studies should address the accuracy of diagnoses, the impact of receiving a diagnosis in a virtual setting, and patient outcomes in order to make informed decisions about the appropriate use of telemedicine in prenatal genetics service delivery.

Embryonic statistical analyses reveal 2 growth phenotypes in mouse models of Down syndrome.

BACKGROUND: Down syndrome is associated with several comorbidities, including intellectual disability, growth restriction, and congenital heart defects. The prevalence of Down syndrome-associated comorbidities is highly variable, and intellectual disability, although fully penetrant, ranges from mild to severe. Understanding the basis of this interindividual variability might identify predictive biomarkers of in utero and postnatal outcomes that could be used as endpoints to test the efficacy of future therapeutic interventions. OBJECTIVE: The main objective of this study was to examine if antenatal interindividual variability exists in mouse models of Down syndrome and whether applying statistical approaches to clinically relevant measurements (ie, the weights of the embryo, placenta, and brain) could define cutoffs that discriminate between subgroups of trisomic embryos. STUDY DESIGN: Three commonly used mouse models of Down syndrome (Dp(16)1/Yey, Ts65Dn, and Ts1Cje) and a new model (Ts66Yah) were used in this study. Trisomic and euploid littermate embryos were used from each model with total numbers of 102 for Ts66Yah, 118 for Dp(16)1/Yey, 92 for Ts65Dn, and 126 for Ts1Cje. Placental, embryonic, and brain weights and volumes at embryonic day 18.5 were compared between genotypes in each model. K-mean clustering analysis was applied to embryonic and brain weights to identify severity classes in trisomic embryos, and brain and placental volumetric measurements were compared between genotypes and classes for each strain. In addition, Ts66Yah embryos were examined for malformations because embryonic phenotypes have never been examined in this model. RESULTS: Reduced body and brain weights were present in Ts66Yah, Dp(16)1/Yey, and Ts65Dn embyos. Cluster analysis identified 2 severity classes in trisomic embryos-mild and severe-in all 4 models that were distinguishable using a putative embryonic weight cutoff of <0.5 standard deviation below the mean. Ts66Yah trisomic embryos develop congenital anomalies that are also found in humans with Down syndrome, including congenital heart defects and renal pelvis dilation. CONCLUSION: Statistical approaches applied to clinically relevant measurements revealed 2 classes of phenotypic severity in trisomic mouse models of Down syndrome. Analysis of severely affected trisomic animals may facilitate the identification of biomarkers and endpoints that can be used to prenatally predict outcomes and the efficacy of treatments.

Phenylalanine hydroxylase deficiency treatment and management: A systematic evidence review of the American College of Medical Genetics and Genomics (ACMG).

PURPOSE: Elevated serum phenylalanine (Phe) levels due to biallelic pathogenic variants in phenylalanine hydroxylase (PAH) may cause neurodevelopmental disorders or birth defects from maternal phenylketonuria. New Phe reduction treatments have been approved in the last decade, but uncertainty on the optimal lifespan goal Phe levels for patients with PAH deficiency remains. METHODS: We searched Medline and Embase for evidence of treatment concerning PAH deficiency up to September 28, 2021. Risk of bias was evaluated based on study design. Random-effects meta-analyses were performed to compare IQ, gestational outcomes, and offspring outcomes based on Phe ≤ 360 µmol/L vs > 360 µmol/L and reported as odds ratio and 95% CI. Remaining results were narratively synthesized. RESULTS: A total of 350 studies were included. Risk of bias was moderate. Lower Phe was consistently associated with better outcomes. Achieving Phe ≤ 360 µmol/L before conception substantially lowered the risk of negative effect to offspring in pregnant individuals (odds ratio = 0.07, 95% CI = 0.04-0.14; P < .0001). Adverse events due to pharmacologic treatment were common, but medication reduced Phe levels, enabling dietary liberalization. CONCLUSIONS: Reduction of Phe levels to ≤360 µmol/L through diet or medication represents effective interventions to treat PAH deficiency.

Underlying genetic etiologies of congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is often detectable prenatally. Advances in genetic testing have made it possible to obtain a molecular diagnosis in many fetuses with CDH. Here, we review the aneuploidies, copy number variants (CNVs), and single genes that have been clearly associated with CDH. We suggest that array-based CNV analysis, with or without a chromosome analysis, is the optimal test for identifying chromosomal abnormalities and CNVs in fetuses with CDH. To identify causative sequence variants, whole exome sequencing (WES) is the most comprehensive strategy currently available. Whole genome sequencing (WGS) with CNV analysis has the potential to become the most efficient and effective means of identifying an underlying diagnosis but is not yet routinely available for prenatal diagnosis. We describe how to overcome and address the diagnostic and clinical uncertainty that may remain after genetic testing, and review how a molecular diagnosis may impact recurrence risk estimations, mortality rates, and the availability and outcomes of fetal therapy. We conclude that after the prenatal detection of CDH, patients should be counseled about the possible genetic causes of the CDH, and the genetic testing modalities available to them, in accordance with generally accepted guidelines for pretest counseling in the prenatal setting.

Novel insights from fetal and placental phenotyping in 3 mouse models of Down syndrome.

BACKGROUND: In human fetuses with Down syndrome, placental pathology, structural anomalies and growth restriction are present. There is currently a significant lack of information regarding the early life span in mouse models of Down syndrome. OBJECTIVE: The objective of this study was to examine embryonic day 18.5 and placental phenotype in the 3 most common mouse models of Down syndrome (Ts65Dn, Dp(16)1/Yey, Ts1Cje). Based on prenatal and placental phenotyping in 3 mouse models of Down syndrome, we hypothesized that one or more of them would have a similar phenotype to human fetuses with trisomy 21, which would make it the most suitable for in utero treatment studies. STUDY DESIGN: Here, C57BL6J/6 female mice were mated to Dp(16)1/Yey and Ts1Cje male mice and Ts65Dn female mice to C57BL/B6Eic3Sn.BLiAF1/J male mice. At embryonic day 18.5, dams were euthanized. Embryos and placentas were examined blindly for weight and size. Embryos were characterized as euploid or trisomic, male or female by polymerase chain reaction. A subset of embryos (34 euploid and 34 trisomic) were examined for malformations. RESULTS: The Ts65Dn mouse model showed the largest differences in fetal growth, brain development, and placental development when comparing euploid and trisomic embryos. For the Dp(16)1/Yey mouse model, genotype did not impact fetal growth, but there were differences in brain and placental development. For the Ts1Cje mouse model, no significant association was found between genotype and fetal growth, brain development, or placental development. Euploid mouse embryos had no congenital anomalies; however, 1 mouse embryo died. Hepatic necrosis was seen in 6 of 12 Dp(16)1/Yey (50%) and 1 of 12 Ts1Cje (8%) mouse embryos; hepatic congestion or inflammation was observed in 3 of 10 Ts65Dn mouse embryos (30%). Renal pelvis dilation was seen in 5 of 12 Dp(16)1/Yey (42%), 5 of 10 Ts65Dn (50%), and 3 of 12 Ts1Cje (25%) mouse embryos. In addition, 1 Ts65Dn mouse embryo and 1 Dp(16)1/Yey mouse embryo had an aortic outflow abnormality. Furthermore, 2 Ts1Cje mouse embryos had ventricular septal defects. Ts65Dn mouse placentas had increased spongiotrophoblast necrosis. CONCLUSION: Fetal and placental growth showed varying trends across strains. Congenital anomalies were primarily seen in trisomic embryos. The presence of liver abnormalities in all 3 mouse models of Down syndrome (10 of 34 cases) is a novel finding. Renal pelvis dilation was also common (13 of 34 cases). Future research will examine human autopsy material to determine if these findings are relevant to infants with Down syndrome. Differences in placental histology were also observed among strains.

Omphalocele-What should we tell the prospective parents?

An omphalocele is a congenital defect in the abdominal wall characterized by absent abdominal muscles, fascia, and skin. The characteristic ultrasound appearance includes a midline defect with herniation of abdominal contents into the base of the umbilical cord. Other anatomic abnormalities are seen in approximately 50% of cases, most notably cardiac defects (19%-32%). Approximately, 50% of cases are associated with genetic and multiple malformation syndromes including trisomy 13/18, pentalogy of Cantrell and Beckwith-Wiedemann syndrome. Therefore, a thorough evaluation is recommended, including detailed anatomic survey, fetal echocardiogram, genetic counseling, and prenatal diagnostic testing. Overall prognosis depends on the size of the omphalocele, genetic studies, and associated anomalies. Early prenatal diagnosis remains important in order to provide parental counseling and assist in pregnancy management. Delivery should occur at a tertiary care center. Timing and mode of delivery should be based on standard obstetric indications with cesarean delivery reserved for large omphalocele (>5 cm) or those that involve the fetal liver. Neonatal management involves either primary or staged reduction, both of which can be associated with a prolonged neonatal hospitalization.

The Effect of Maternal Obesity on Oxytocin Requirements to Achieve Vaginal Delivery.

OBJECTIVE: Our objective was to determine if obese women are more likely to require oxytocin rates > 20 mU/min to achieve vaginal delivery, compared with normal weight women. STUDY DESIGN: This is a retrospective cohort study of deliveries at the MedStar Washington Hospital Center and MedStar Georgetown University Hospital. RESULTS: There were 4,284 births included in the analysis. Thirty-three per cent of deliveries were among women classified as overweight (body mass index [BMI] 25-29.9 kg/m2) and 58% were among women classified as obese (BMI >30.0 kg/m2), 12% were classified as class III obesity (BMI >40 kg/m2). Overall 110 (2.6%) women required an oxytocin rate of >20 mU/min. Doses of oxytocin >20 mU/min for women in the overweight, class I obesity, and class II obesity groups were 2.6, 1.9, and 1.6%, respectively. Deliveries among women with class III obesity had a significantly longer duration of oxytocin exposure (10.7 hours) compared with the normal weight group (8.2 hours, p < 0.001), and had a higher maximum rate of oxytocin compared (10 mU/min) to normal weight women (8 mU/min, p < 0.001). CONCLUSION: Obese women are more likely to require oxytocin rates more than 20 mU/min, higher doses of oxytocin, and greater duration of oxytocin exposure to achieve a vaginal delivery.

Neonatal and maternal outcomes of pregnancies with a fetal diagnosis of congenital heart disease using a standardized delivery room management protocol.

OBJECTIVE: We sought to determine if fetuses with prenatally diagnosed congenital heart disease (CHD) were more likely to undergo cesarean delivery in the setting of a non-reassuring fetal heart rate tracing (NRFHT) and to determine if those fetuses were more likely to have a fetal acidosis. STUDY DESIGN: A retrospective cohort study of neonates prenatally diagnosed with CHD from August 2010 to July 2016. The control group consisted of gestational age matched controls without CHD. RESULTS: Each group consisted of 143 patients. The most common reason for cesarean delivery was a NRFHT (control 31% vs CHD 35%, p = 0.67). Fetal acidosis was a rare outcome occurring in only five controls (3.5%) and 11 cases (7.7%) (p = 0.12). CONCLUSION: These findings demonstrate that with multidisciplinary care coordination, fetuses with a prenatal diagnosis of CHD have similar cesarean rates, labor and delivery management, and delivery room compromise as healthy fetuses.

Placental development and function in trisomy 21 and mouse models of Down syndrome: Clues for studying mechanisms underlying atypical development.

Down syndrome (DS) is the most common genetic disorder leading to developmental disability. The phenotypes associated with DS are complex and vary between affected individuals. Placental abnormalities in DS include differences in cytotrophoblast fusion that affect subsequent conversion to syncytiotrophoblast, atypical oxidative stress/antioxidant balance, and increased expression of genes that are also upregulated in the brains of individuals with Alzheimer's disease. Placentas in DS are prematurely senescent, showing atypical evidence of mineralization. Fetuses with DS are especially susceptible to adverse obstetric outcomes, including early in utero demise, stillbirth and growth restriction, all of which are related to placental function. The placenta, therefore, may provide key insights towards understanding the phenotypic variability observed in individuals with DS and aid in identifying biomarkers that can be used to evaluate phenotypic severity and prenatal treatments in real time. To address these issues, many different mouse models of DS have been generated to identify the mechanisms underlying developmental changes in many organ systems. Little is known, however, regarding placental development in the currently available mouse models of DS. Based upon the relative paucity of data on placental development in preclinical mouse models of DS, we recommend that future evaluation of new and existing models routinely include histologic and functional assessments of the placenta. In this paper we summarize studies performed in the placentas of both humans and mouse models with DS, highlighting gaps in knowledge and suggesting directions for future research.

Umbilical Cord Blood Gas in Newborns with Prenatal Diagnosis of Congenital Heart Disease: Insight into In-Utero and Delivery Hemodynamics.

The primary objective was to determine if newborns with congenital heart disease (CHD) are at a higher risk for acidosis at delivery as determined by cord blood gas analysis. The secondary objective was to determine whether specific fetal cardiac diagnosis, delivery method, or duration of labor is associated with an increased risk for acidosis. This was a retrospective study of newborns with CHD diagnosed prenatally and comparable patients without a CHD diagnosis. Study participants included 134 CHD-affected newborns and 134 controls. Median UA pH in CHD newborns was 7.22 (CI 7.2-7.4) and in controls it was 7.22 (CI 7.21-7.24), p = 0.91. There was no difference in median UA pH comparing newborns with single-ventricle CHD and two-ventricle CHD [7.23 (CI 7.2-7.26) vs. 7.22 (CI 7.22-7.24), p = 0.77], or newborns with CHD with aortic obstruction and those without aortic obstruction [7.23 (CI 7.21-7.26) vs. 7.22 (CI 7.2-7.24), p = 0.29]. After controlling for delivery method and duration of labor, CHD patients who underwent a spontaneous vaginal delivery were found to have a declining median UA pH as labor progressed. Our results show that newborns with CHD have a normal UA pH at delivery suggesting a compensated circulation in utero. Spontaneous vaginal delivery with a progressively longer duration of labor in CHD newborns was associated with lower UA pH. This suggests that fetuses with CHD may be at risk for hemodynamic instability at birth with a longer duration of labor as a potentially modifiable factor to improve outcome.

Use of the STROBE Checklist to Evaluate the Reporting Quality of Observational Research in Obstetrics.

OBJECTIVE: To evaluate observational research manuscripts submitted to Obstetrics & Gynecology to determine the level of adherence to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist and highlight specific areas that could be improved. METHODS: A scoring system based on the STROBE checklist was developed and validated for consistency by volunteer medical students or doctors. Using this scoring system, we performed a cross-sectional analysis on 198 observational research manuscripts submitted to Obstetrics & Gynecology from 2008 to 2016. Each manuscript was given a score based on the STROBE checklist. Comparisons were made among acceptance status, country of origin, and study type. Descriptive statistics (means, medians, and frequencies) were calculated for each manuscript category. The t test or Wilcoxon rank-sum test was used to compare differences between two groups and analysis of variance or the Kruskal-Wallis test was used to compare differences among three or more groups. RESULTS: There was a statistically significant difference between the mean score for accepted (23.2±2.7) compared with rejected (19.7±4.1) manuscripts (P<.001). This difference was not seen when comparing country of origin and study type. Poor reporting was seen among all manuscript categories for objectives, study size, missing data, study participants, and translation of risk. Additionally, rejected manuscripts had poor reporting for eligibility criteria, variables, bias and confounding, statistical methods, unadjusted and adjusted estimates, and category boundaries. CONCLUSION: Overall, accepted manuscripts show better adherence to the STROBE checklist, but there are several critical items that are poorly reported in all manuscripts.

Differences in prenatal aneuploidy screening among African-American women with hemoglobin S variants.

OBJECTIVE: It has been shown that hemoglobinopathies increase the risk of pregnancy complications and placental dysfunction. This could alter the placental analytes examined during prenatal aneuploidy screening. Our objective was to determine whether there is a difference in maternal serum screening results for women with hemoglobin S variants (AS, SS, SC, S/beta thalassemia) compared with women with normal hemoglobin (AA). STUDY DESIGN: This is a retrospective cohort study in African-American women receiving aneuploidy screening at MedStar Washington Hospital Center from 2008 to 2015. We evaluated 79 women with hemoglobin S variants (69 AS and 10 sickle cell disease (SCD)) and 79 controls. Descriptive statistics (means, medians, and frequencies) were calculated for each group. For the continuous variables, differences in the averages between the two groups were tested using the t test or Wilcoxon rank sum test. Differences in the averages between three or more groups were tested using the analysis of variance test or the Kruskal-Wallis test. RESULTS: Demographics were similar between cases and controls. The overall screen positive rate for Down syndrome among patients with sickle cell trait (AS) was 3% (2/69). For patients with SCD, the overall screen positive rate was 10% (1/10). None of the women in the control population (AA) has a positive Down syndrome screening result (0/79). CONCLUSION: As expected, the screen positive rate in patients with hemoglobin S variants was higher than controls, however, patients with sickle cell trait do not appear to be at an increased risk for false-positive results with serum aneuploidy screening compared with the general population. We did, however, find an increased risk of false-positive quad screen results in patients with sickle cell disease.