Low Prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 Among Pregnant and Postpartum Patients With Universal Screening in Seattle, Washington.

We found low prevalence of SARS-CoV-2 (2.7% [5/188]) among pregnant and postpartum patients with universal testing. Prevalence among symptomatic patients was similar under initial targeted screening (22.2% [4/18]) and universal approaches (19.1% [8/42]). Among 170 asymptomatic patients, 2 were positive or inconclusive, respectively; repeat testing at 24 hours was negative.

Positive predictive value of non-invasive prenatal screening for fetal chromosome disorders using cell-free DNA in maternal serum: independent clinical experience of a tertiary referral center.

BACKGROUND: Non-invasive prenatal screening (NIPS) for fetal chromosome abnormalities using cell-free deoxyribonucleic acid (cfDNA) in maternal serum has significantly influenced prenatal diagnosis of fetal aneuploidies since becoming clinically available in the fall of 2011. High sensitivity and specificity have been reported in multiple publications, nearly all of which have been sponsored by the commercial performing laboratories. Once results are returned, positive and negative predictive values (PPVs, NPVs) are the performance metrics most relevant to clinical management. The purpose of this report is to present independent data on the PPVs of NIPS in actual clinical practice. METHODS: Charts were retrospectively reviewed for patients who had NIPS and were seen March 2012 to December 2013 in a tertiary academic referral center. NIPS results were compared to diagnostic genetic test results, fetal ultrasound results, and clinical phenotype/outcomes. The PPV was calculated using standard epidemiological methods. Correlation between screen results and both maternal age at delivery and gestational age at time of screening was assessed using Wilcoxon's rank sum test. RESULTS: Of 632 patients undergoing NIPS, 92 % of tests were performed in one of the four major commercial laboratories offering testing. However, all four laboratories are represented in both the normal and abnormal results groups. There were 55 abnormal NIPS results. Forty-one of 55 abnormal NIPS results were concordant with abnormal fetal outcomes, 12 were discordant, and 2 were undetermined. The PPV for all conditions included in the screen was 77.4 % (95 % CI, 63.4 - 87.3). Of 578 patients with normal NIPS results, normal pregnancy outcome was confirmed for 156 (27 %) patients. This incomplete follow-up of normal NIPS results does not affect PPV calculations, but it did preclude calculations of sensitivity, specificity, and NPV. Maternal age at delivery was significantly lower for patients with abnormal discordant results, compared to patients with abnormal concordant results (P = 0.034). Gestational age at time of screening was not associated with concordance of screen results (P = 0.722). CONCLUSIONS: The experience of using NIPS in clinical practice confirms that abnormal results cannot be considered diagnostic. Pre-test counseling should emphasize this. Diagnostic genetic testing should always be offered following abnormal NIPS results.

Differences in risk factors for retinopathy of prematurity development in paired twins: a Chinese population study.

PURPOSE: To determine the differences in risk factors for retinopathy of prematurity (ROP) in paired twins. METHODS: A retrospective medical record review was performed for all paired twins screened for ROP between 2007 and 2012. Screening was offered to very low birth weight (≤ 1500 grams) and preterm (≤ 32 weeks) neonates. Twins 1 and 2 were categorized based on the order of delivery. Maternal and neonatal covariates were analyzed using univariate and multivariate regression analyses for both ROP and Type 1 ROP. RESULTS: In 34 pairs of Chinese twins, the mean gestational age (GA) was 30.2 ± 2.0 weeks. In Twin 1, smaller GA (OR = 0.44, P = 0.02), higher mean oxygen concentration (OR = 1.34, P = 0.03), presence of thrombocytopenia (OR = 1429.60, P < 0.0001), and intraventricular hemorrhage (OR = 18.67, P = 0.03) were significant risk factors for ROP. For Twin 2, a smaller GA (OR = 0.45, P = 0.03) was the only risk factor. There were no significant risk factors for ROP in Twin 1 or Twin 2 on multivariate analysis. CONCLUSION: In Chinese twin pairs, smaller GA was the only common risk factor for ROP while Twin 1 was more susceptible to the postnatal risks for ROP.

Germline mosaicism does not explain the maternal age effect on trisomy.

A variety of hypotheses have been proposed to explain the association between trisomy and increasing maternal age in humans, virtually all of which assume that the underlying mechanisms involve meiotic errors. However, recently Hultén and colleagues [Hulten et al., 2010b] proposed a provocative model-the Oocyte Mosaicism Selection Model (OMSM)-that links age-dependent trisomy 21 to pre-meiotic errors in the ovary. Specifically, they propose that nondisjunctional events occur in a proportion of germ cells as they mitotically proliferate, resulting in mosaicism for trisomy 21. Assuming that the presence of an additional chromosome 21 delays meiotic progression, these cells would be ovulated later in reproductive life, resulting in an age-dependent increase in aneuploid eggs. Because this model has important clinical implications, we initiated studies to test it. We first analyzed oocytes from two trisomy 21 fetuses, combining immunostaining with FISH to determine the likelihood of detecting the additional chromosome 21 at different stages of meiosis. The detection of trisomy was enhanced during the earliest stage of prophase (leptotene), before homologs synapsed. Accordingly, in subsequent studies we examined the chromosome content of leptotene oocytes in seven second trimester female fetuses, analyzing three chromosomes commonly associated with human trisomies (i.e., 13, 16, and 21). In contrast to the prediction of the OMSM, we found no evidence of trisomy mosaicism for any chromosome. We conclude that errors in pre-meiotic germ cells are not a major contributor to human aneuploidy and do not provide an explanation for the age-related increase in trisomic conceptions.

Ambiguous genitalia: what prenatal genetic testing is practical?

Concern for ambiguous genitalia or chromosome-phenotype discordance detected in a prenatal setting has increased over the last two decades. Practitioners faced with this prenatal finding have a variety of genetic tests available to them; however, it is unclear to what extent prenatal testing for disorders of sex development (DSD) is useful or practical. We undertook a retrospective review of the medical records of 140 individuals evaluated through the DSD clinic at Seattle Children's Hospital with birthdates from 01/01/1994 through 08/16/2011 to determine the rate of prenatal detection of ambiguous genitalia in individuals with DSD, what prenatal diagnostic workup was undertaken, and the postnatal outcome, including whether a postnatal genetic diagnosis was confirmed. Of all 140 subjects, 34 (24%) were identified prenatally. The most common postnatal diagnoses were penoscrotal hypospadias with transposition of the scrotum with no known genetic cause (24/140; 17%) and 21-hydroxylase deficiency (20/140; 14%). Apart from these, no single diagnosis comprised more than a few cases. Prenatal diagnostic testing varied widely, from no tests to multiple molecular tests with amniotic fluid hormone concentrations. In the absence of other fetal anomalies or growth retardation on ultrasound, prenatal karyotype with fluorescence in situ hybridization for the SRY gene is the most useful test when ambiguous genitalia is suspected. Further prenatal testing for Smith-Lemli-Opitz syndrome in 46,XY individuals and congenital adrenal hyperplasia in 46,XX individuals may be considered. However, targeted molecular testing for rare DSD conditions in the absence of a family history of DSD has a low yield.

Clinical, neuroradiological and genetic findings in pontocerebellar hypoplasia.

Pontocerebellar hypoplasia is a group of autosomal recessive neurodegenerative disorders with prenatal onset. The common characteristics are cerebellar hypoplasia with variable atrophy of the cerebellum and the ventral pons. Supratentorial involvement is reflected by variable neocortical atrophy, ventriculomegaly and microcephaly. Mutations in the transfer RNA splicing endonuclease subunit genes (TSEN54, TSEN2, TSEN34) were found to be associated with pontocerebellar hypoplasia types 2 and 4. Mutations in the mitochondrial transfer RNA arginyl synthetase gene (RARS2) were associated with pontocerebellar hypoplasia type 6. We studied a cohort of 169 patients from 141 families for mutations in these genes, of whom 106 patients tested positive for mutations in one of the TSEN genes or the RARS2 gene. In order to delineate the neuroradiological and clinical phenotype of patients with mutations in these genes, we compared this group with 63 patients suspected of pontocerebellar hypoplasia who were negative on mutation analysis. We found a strong correlation (P < 0.0005) between TSEN54 mutations and a dragonfly-like cerebellar pattern on magnetic resonance imaging, in which the cerebellar hemispheres are flat and severely reduced in size and the vermis is relatively spared. Mutations in TSEN54 are clinically associated with dyskinesia and/or dystonia and variable degrees of spasticity, in some cases with pure generalized spasticity. Nonsense or splice site mutations in TSEN54 are associated with a more severe phenotype of more perinatal symptoms, ventilator dependency and early death. In addition, we present ten new mutations in TSEN54, TSEN2 and RARS2. Furthermore, we show that pontocerebellar hypoplasia type 1 together with elevated cerebrospinal fluid lactate may be caused by RARS2 mutations.

Meiotic recombination in human oocytes.

Studies of human trisomies indicate a remarkable relationship between abnormal meiotic recombination and subsequent nondisjunction at maternal meiosis I or II. Specifically, failure to recombine or recombination events located either too near to or too far from the centromere have been linked to the origin of human trisomies. It should be possible to identify these abnormal crossover configurations by using immunofluorescence methodology to directly examine the meiotic recombination process in the human female. Accordingly, we initiated studies of crossover-associated proteins (e.g., MLH1) in human fetal oocytes to analyze their number and distribution on nondisjunction-prone human chromosomes and, more generally, to characterize genome-wide levels of recombination in the human female. Our analyses indicate that the number of MLH1 foci is lower than predicted from genetic linkage analysis, but its localization pattern conforms to that expected for a crossover-associated protein. In studies of individual chromosomes, our observations provide evidence for the presence of "vulnerable" crossover configurations in the fetal oocyte, consistent with the idea that these are subsequently translated into nondisjunctional events in the adult oocyte.

LSD1 is required for euchromatic origin firing and replication timing.

The chromatin-based rule governing the selection and activation of replication origins remains to be elucidated. It is believed that DNA replication initiates from open chromatin domains; thus, replication origins reside in open and active chromatin. However, we report here that lysine-specific demethylase 1 (LSD1), which biochemically catalyzes H3K4me1/2 demethylation favoring chromatin condensation, interacts with the DNA replication machinery in human cells. We find that LSD1 level peaks in early S phase, when it is required for DNA replication by facilitating origin firing in euchromatic regions. Indeed, euchromatic zones enriched in H3K4me2 are the preferred sites for the pre-replicative complex (pre-RC) binding. Remarkably, LSD1 deficiency leads to a genome-wide switch of replication from early to late. We show that LSD1-engaged DNA replication is mechanistically linked to the loading of TopBP1-Interacting Checkpoint and Replication Regulator (TICRR) onto the pre-RC and subsequent recruitment of CDC45 during origin firing. Together, these results reveal an unexpected role for LSD1 in euchromatic origin firing and replication timing, highlighting the importance of epigenetic regulation in the activation of replication origins. As selective inhibitors of LSD1 are being exploited as potential cancer therapeutics, our study supports the importance of leveraging an appropriate level of LSD1 to curb the side effects of anti-LSD1 therapy.

Pregnancy in cystic fibrosis: Review of the literature and expert recommendations.

Cystic fibrosis (CF) was historically a disease largely afflicting children. Due to therapeutic advancements, there are now more adults with CF than children. In the past decade, medications including Cystic Fibrosis Transmembrane conductance Regulator (CFTR) modulators became available that treat the underlying cause of CF and are dramatically improving lung function as well as quality and quantity of life for people with CF. As a result, more women with CF are becoming pregnant. We gathered a panel of experts in CF care, family planning, high risk obstetrics, nutrition, genetics and women with CF to review current literature on pregnancies and to provide care recommendations for this unique population.

EXIT procedure: technique and indications with prenatal imaging parameters for assessment of airway patency.

Successful management of fetal conditions in which airway obstruction is anticipated is now possible because of advances in prenatal imaging and the development of innovative techniques to secure the fetal airway before complete separation of the fetus from the maternal circulation. Fetal ultrasonography and fetal magnetic resonance imaging are complementary imaging modalities in the assessment of fetuses with potential airway obstruction. The ex utero intrapartum therapy (EXIT) procedure is used to secure the fetal airway before complete delivery of the fetus. However, successful intrapartum treatment of fetuses who may need prolonged placental support depends on a multidisciplinary assessment in which the benefits of the EXIT procedure for the fetus are weighed against the risk of maternal complications that may occur during prolongation of the intrapartum period to secure the fetal airway. This multidisciplinary approach requires an understanding of the types of lesions in which intrapartum fetal airway access would be beneficial, a knowledge of the prenatal images that would best delineate the anatomic defect and thus help guide the best approach to securing the airway, and consensus and coordination among medical ethicists, radiologists, obstetric anesthesiologists and obstetricians, pediatric surgeons and anesthesiologists, and neonatologists.

Elucidating the spatially varying relation between cervical cancer and socio-economic conditions in England.

BACKGROUND: Geographically weighted Poisson regression (GWPR) was applied to the relation between cervical cancer disease incidence rates in England and socio-economic deprivation, social status and family structure covariates. Local parameters were estimated which describe the spatial variation in the relations between incidence and socio-economic covariates. RESULTS: A global (stationary) regression model revealed a significant correlation between cervical cancer incidence rates and social status. However, a local (non-stationary) GWPR model provided a better fit with less spatial correlation (positive autocorrelation) in the residuals. Moreover, the GWPR model was able to represent local variation in the relations between cervical cancer incidence and socio-economic covariates across space, whereas the global model represented only the overall (or average) relation for the whole of England. The global model could lead to misinterpretation of the relations between cervical cancer incidence and socio-economic covariates locally. CONCLUSIONS: Cervical cancer incidence was shown to have a non-stationary relationship with spatially varying covariates that are available through national datasets. As a result, it was shown that if low social status sectors of the population are to be targeted preferentially, this targeting should be done on a region-by-region basis such as to optimize health outcomes. While such a strategy may be difficult to implement in practice, the research does highlight the inequalities inherent in a uniform intervention approach.

Development of a prenatal clinical care pathway for uncomplicated gastroschisis and literature review.

BACKGROUND: Gastroschisis is an abdominal wall defect wherein the bowel is herniated into the amniotic fluid. Controversy exists regarding optimal prenatal surveillance strategies that predict fetal well-being and help guide timing of delivery. Our objective was to develop a clinical care pathway for prenatal management of uncomplicated gastroschisis at our institution. METHODS: We performed a review of literature from January 1996 to May 2017 to evaluate prenatal ultrasound (US) markers and surveillance strategies that help determine timing of delivery and optimize outcomes in fetal gastroschisis. RESULTS: A total 63 relevant articles were identified. We found that among the US markers, intraabdominal bowel dilatation, polyhydramnios, and gastric dilatation are potentially associated with postnatal complications. Prenatal surveillance strategy with monthly US starting at 28weeks of gestational age (wGA) and twice weekly non-stress testing beginning at 32wGA is recommended to optimize fetal wellbeing. Timing of delivery should be based on obstetric indications and elective preterm delivery prior to 37wGA is not indicated. CONCLUSIONS: Close prenatal surveillance of fetal gastroschisis is necessary due to the high risk for adverse outcomes including intrauterine fetal demise in the third trimester. Decisions regarding the timing of delivery should take into consideration the additional prematurity-associated morbidity.

Prenatal Imaging Findings Predict Obstructive Fetal Airways Requiring EXIT.

OBJECTIVE: Detection of fetal airway compromise through imaging raises the possible need for ex utero intrapartum treatment (EXIT) procedures. Despite EXIT procedures involving massive resource utilization and posing increased risk to the mother, decisions for EXIT are usually based on anecdotal experience. Our objectives were to analyze prenatal consultations with potential fetal airway obstruction for imaging and obstetric findings used to determine management strategy. METHODS: Retrospective chart review was performed for prenatal abnormal fetal airway consults between 2004-2019 at a quaternary pediatric facility. Data collected included demographics, imaging characteristics, delivery information, and airway management. Our primary outcome was EXIT performance and the secondary outcome was postnatal airway management. Fisher's exact test was used to compare management decisions, outcomes, and imaging findings. RESULTS: Thirty-seven patients met inclusion criteria. The most common diagnoses observed were lymphatic malformation, teratoma, and micrognathia. Of the imaging findings collected, only midline neck mass location was associated with EXIT procedure performance. Factors associated with invasive airway support at birth were mass-induced in-utero neck extension and neck vessel compression, polyhydramnios, and micrognathia. CONCLUSIONS: Multidisciplinary input and interpretation of prenatal imaging can guide management of fetal airway-related pathology. EXIT is an overall safe procedure and can decrease risk due to airway obstruction at birth. We identified in-utero neck extension, neck vessel compression, micrognathia, and polyhydramnios as better indicators of a need for invasive airways measures at birth and suggest use of these criteria in combination with clinical judgement when recommending EXIT. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1357-E1362, 2021.

High-resolution profiling of human cytomegalovirus cell-free DNA in human plasma highlights its exceptionally fragmented nature.

Human cytomegalovirus (CMV) infections comprise a leading cause of newborn impairments worldwide and are pervasive concerns among the immunocompromised. Quantification of CMV viral loads is increasingly used to guide definitions of CMV disease but standardization of CMV quantitation remains problematic, mostly due to differences in qPCR amplicon sizes between clinical laboratories. Here, we used plasma cfDNA sequencing data from 2,208 samples sent for non-invasive prenatal aneuploidy screening to detect CMV and precisely measure the length of CMV fragments in human plasma. CMV reads were identified in 120 (5.4%) samples. Median cfDNA fragment size derived from CMV was significantly shorter than cfDNA derived from human chromosomes (103 vs 172 bp, p < 0.0001), corresponding to the 3rd percentile of human cfDNA. Sequencing of cfDNA from seven plasma samples from transplant patients positive for CMV confirmed the extraordinarily short nature of CMV cfDNA fragment size with a median length of 149 bp. We further show that these high-resolution measurements of CMV DNA fragment size accurately predict measured discrepancies in serum viral load measurements by different qPCR assays. These results highlight the exceptionally fragmented nature of CMV cfDNA and illustrate the promise of plasma cfDNA sequencing for quantitating viral loads through detection of fragments that would be unrecoverable by qPCR.

Global gene expression in the human fetal testis and ovary.

This study describes a temporal profile of gene expression from normal human fetal testes and ovaries. Gonads from 34 fetuses between 9 wk and 20 wk of gestation were obtained from the Department of Pathology and the Birth Defects Research Laboratory at the University of Washington. Relative transcript levels were determined using the Affymetrix Human Genome U133A Plus 2.0 arrays. Sex determination occurs in the human gonad at approximately 6 wk of gestation with development of the testis driven by expression of SRY. In this study, SRY transcript was present and elevated at 9 wk of gestation in the testis but was absent in the ovary. The transcript levels of other testis-specific factors SOX9 and AMH and the steroidogenic genes CYP17A1, CYP11A1, STAR, and HSD17B3 were all significantly higher in the testis. In contrast, transcripts known to be involved in meiosis, including STRA8, SPO11, SYCP3, TEX11, TEX14, and STAG3, showed highest expression in the fetal ovary beginning at Week 12. These gene expression profiles will be a resource for understanding and defining normal gonad development and provide the opportunity to dissect abnormal development.

Clinical practice and genetic counseling for cystic fibrosis and CFTR-related disorders.

Cystic fibrosis transmembrane conductance regulator-related disorders encompass a disease spectrum from focal male reproductive tract involvement in congenital absence of the vas deferens to multiorgan involvement in classic cystic fibrosis. The reproductive, gastrointestinal, and exocrine manifestations of cystic fibrosis transmembrane conductance regulator deficiency are correlated with CFTR genotype, whereas the respiratory manifestations that are the main cause of morbidity and mortality in cystic fibrosis are less predictable. Molecular genetic testing of CFTR has led to new diagnostic strategies and will enable targeting of molecular therapies now in development. Older diagnostic methods that measure sweat chloride and nasal potential difference nonetheless remain important because of their sensitivity and specificity. In addition, the measurement of immunoreactive trypsinogen and the genotyping of CFTR alleles are key to newborn screening programs because of low cost. The multiorgan nature of cystic fibrosis leads to a heavy burden of care, thus therapeutic regimens are tailored to the specific manifestations present in each patient. The variability of cystic fibrosis lung disease and the variable expressivity of mild CFTR alleles complicate genetic counseling for this autosomal recessive disorder. Widespread implementation of newborn screening programs among populations with significant cystic fibrosis mutation carrier frequencies is expected to result in increasing demands on genetic counseling resources.

Fetal skeletal dysplasia: an approach to diagnosis with illustrative cases.

Skeletal dysplasias are a heterogeneous group of conditions associated with various abnormalities of the skeleton. These conditions are caused by widespread disturbance of bone growth, beginning during the early stages of fetal development and evolving throughout life. Despite recent advances in imaging, fetal skeletal dysplasias are difficult to diagnose in utero due to a number of factors, including the large number of skeletal dysplasias and their phenotypic variability with overlapping features, lack of precise molecular diagnosis for many disorders, lack of a systematic approach, the inability of ultrasonography (US) to provide an integrated view, and variability in the time at which findings manifest in some skeletal dysplasias. US of suspected skeletal dysplasia involves systematic imaging of the long bones, thorax, hands and feet, skull, spine, and pelvis. Assessment of the fetus with three-dimensional US has been shown to improve diagnostic accuracy, since additional phenotypic features not detectable at two-dimensional US may be identified. The radiologist plays a major role in making an accurate diagnosis; however, representatives of other disciplines, including clinicians, molecular biologists, and pathologists, can also provide important diagnostic information.

A Paradigm Shift: Considerations in Prenatal Cell-Free DNA Screening.

BACKGROUND: Testing to determine the health of a fetus has undergone multiple iterations since the widespread adoption of amniocentesis in the 1970s, including several combinations of ultrasound and/or maternal serum screening. The clinical paradigm for prenatal screening for fetal chromosome aneuploidies was transformed by the introduction of cell-free DNA (cfDNA) screening or noninvasive prenatal screening in 2011. CONTENT: The clinical performance of cfDNA screening is well-established for the most common autosomal and sex chromosome aneuploidies with a detection rate exceeding 90% for all aneuploidies. One of the most significant advantages of cfDNA screening relative to maternal serum screening is the markedly reduced false-positive rate, which is <0.5%. The clinical implementation of cfDNA screening is discussed at length, including key biological, preanalytical, and analytical factors that affect test performance. SUMMARY: cfDNA prenatal screening for whole chromosome aneuploidies has become routine in high-risk obstetric populations. There is tremendous interest in expanding cfDNA screening to the general obstetric population. Early studies suggest that routine application of cfDNA screening is both feasible and effective, although significant economic and quality control considerations remain.

Gaps in Training in Interdisciplinary Social and Behavioral Sciences and Applications Among Undergraduate and Graduate Students in the 22 Top-Ranked Schools of Public Health in China.

The next generation of public health professionals requires rigorous training in behavioral health, in order to design effective behavioral interventions to respond effectively to the epidemiological transition in China. This study aimed to investigate issues in training in social and behavioral sciences in public health in China. A cross-sectional survey was conducted among 1285 and 835 last-year undergraduate and graduate public health students in 2013. The results showed that (1) majority of undergraduate students but a minority of graduate students had enrolled in psychology, social medicine, and health promotion courses; (2) very few had enrolled in other social and behavioral sciences courses; (3) high percentages of students perceived significance, needs, and interests related to social sciences courses; (4) very few were familiar with commonly used behavioral health theories and constructs, or had applied such theories/constructs to their thesis. The situation deviates from international accreditation requirement. A timely review and benchmarking are warranted.