Mean Arterial Pressure and Neonatal Outcomes in Pregnancies Complicated by Mild Chronic Hypertension.

OBJECTIVE: To estimate the association between mean arterial pressure during pregnancy and neonatal outcomes in participants with chronic hypertension using data from the CHAP (Chronic Hypertension and Pregnancy) trial. METHODS: A secondary analysis of the CHAP trial, an open-label, multicenter randomized trial of antihypertensive treatment in pregnancy, was conducted. The CHAP trial enrolled participants with mild chronic hypertension (blood pressure [BP] 140-159/90-104 mm Hg) and singleton pregnancies less than 23 weeks of gestation, randomizing them to active treatment (maintained on antihypertensive therapy with a goal BP below 140/90 mm Hg) or standard treatment (control; antihypertensives withheld unless BP reached 160 mm Hg systolic BP or higher or 105 mm Hg diastolic BP or higher). We used logistic regression to measure the strength of association between mean arterial pressure (average and highest across study visits) and to select neonatal outcomes. Unadjusted and adjusted odds ratios (per 1-unit increase in millimeters of mercury) of the primary neonatal composite outcome (bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, or intraventricular hemorrhage grade 3 or 4) and individual secondary outcomes (neonatal intensive care unit admission [NICU], low birth weight [LBW] below 2,500 g, and small for gestational age [SGA]) were calculated. RESULTS: A total of 2,284 participants were included: 1,155 active and 1,129 control. Adjusted models controlling for randomization group demonstrated that increasing average mean arterial pressure per millimeter of mercury was associated with an increase in each neonatal outcome examined except NEC, specifically neonatal composite (adjusted odds ratio [aOR] 1.12, 95% CI, 1.09-1.16), NICU admission (aOR 1.07, 95% CI, 1.06-1.08), LBW (aOR 1.12, 95% CI, 1.11-1.14), SGA below the fifth percentile (aOR 1.03, 95% CI, 1.01-1.06), and SGA below the 10th percentile (aOR 1.02, 95% CI, 1.01-1.04). Models using the highest mean arterial pressure as opposed to average mean arterial pressure also demonstrated consistent associations. CONCLUSION: Increasing mean arterial pressure was positively associated with most adverse neonatal outcomes except NEC. Given that the relationship between mean arterial pressure and adverse pregnancy outcomes may not be consistent at all mean arterial pressure levels, future work should attempt to further elucidate whether there is an absolute threshold or relative change in mean arterial pressure at which fetal benefits are optimized along with maternal benefits. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02299414.

Trends in Reporting of Nuchal Translucency Measurements After the Clinical Introduction of Cell-Free DNA Screening.

Nuchal translucency (NT) measurement in conjunction with serum analytes has been used for first-trimester aneuploidy screening in the United States since 2005. We sought to analyze the trends in reporting of NT measurements to the Nuchal Translucency Quality Review program in all pregnancies beginning after the clinical introduction of cell-free DNA (cfDNA) screening for fetal aneuploidy in 2011. Overall, reported NT measurements decreased 74.3% from 2012 to 2022. A similar decline was noted among individuals with pregnancies at increased risk for aneuploidy based on patient age and twin gestations. The decrease in reporting aligns temporally with the availability of cfDNA screening and the coronavirus disease 2019 (COVID-19) pandemic.

The Role of cfDNA Biomarkers and Patient Data in the Early Prediction of Preeclampsia: Artificial Intelligence Model.

OBJECTIVE: Accurate individualized assessment of preeclampsia risk enables the identification of patients most likely to benefit from initiation of low-dose aspirin at 12-16 weeks' gestation when there is evidence for its effectiveness, as well as guiding appropriate pregnancy care pathways and surveillance. The primary objective of this study was to evaluate the performance of artificial neural network models for the prediction of preterm preeclampsia (<37 weeks' gestation) using patient characteristics available at the first antenatal visit and data from prenatal cell-free DNA (cfDNA) screening. Secondary outcomes were prediction of early onset preeclampsia (<34 weeks' gestation) and term preeclampsia (≥37 weeks' gestation). METHODS: This secondary analysis of a prospective, multicenter, observational prenatal cfDNA screening study (SMART) included singleton pregnancies with known pregnancy outcomes. Thirteen patient characteristics that are routinely collected at the first prenatal visit and two characteristics of cfDNA, total cfDNA and fetal fraction (FF), were used to develop predictive models for early-onset (<34 weeks), preterm (<37 weeks), and term (≥37 weeks) preeclampsia. For the models, the 'reference' classifier was a shallow logistic regression (LR) model. We also explored several feedforward (non-linear) neural network (NN) architectures with one or more hidden layers and compared their performance with the LR model. We selected a simple NN model built with one hidden layer and made up of 15 units. RESULTS: Of 17,520 participants included in the final analysis, 72 (0.4%) developed early onset, 251 (1.4%) preterm, and 420 (2.4%) term preeclampsia. Median gestational age at cfDNA measurement was 12.6 weeks and 2,155 (12.3%) had their cfDNA measurement at 16 weeks' gestation or greater. Preeclampsia was associated with higher total cfDNA (median 362.3 versus 339.0 copies/ml cfDNA; p<0.001) and lower FF (median 7.5% versus 9.4%; p<0.001). The expected, cross-validated area under the curve (AUC) scores for early onset, preterm, and term preeclampsia were 0.782, 0.801, and 0.712, respectively for the LR model, and 0.797, 0.800, and 0.713, respectively for the NN model. At a screen-positive rate of 15%, sensitivity for preterm preeclampsia was 58.4% (95% CI 0.569, 0.599) for the LR model and 59.3% (95% CI 0.578, 0.608) for the NN model.The contribution of both total cfDNA and FF to the prediction of term and preterm preeclampsia was negligible. For early-onset preeclampsia, removal of the total cfDNA and FF features from the NN model was associated with a 6.9% decrease in sensitivity at a 15% screen positive rate, from 54.9% (95% CI 52.9-56.9) to 48.0% (95% CI 45.0-51.0). CONCLUSION: Routinely available patient characteristics and cfDNA markers can be used to predict preeclampsia with performance comparable to other patient characteristic models for the prediction of preterm preeclampsia. Both LR and NN models showed similar performance.

Genetic ancestry and diagnostic yield of exome sequencing in a diverse population.

It has been suggested that diagnostic yield (DY) from Exome Sequencing (ES) may be lower among patients with non-European ancestries than those with European ancestry. We examined the association of DY with estimated continental/subcontinental genetic ancestry in a racially/ethnically diverse pediatric and prenatal clinical cohort. Cases (N = 845) with suspected genetic disorders underwent ES for diagnosis. Continental/subcontinental genetic ancestry proportions were estimated from the ES data. We compared the distribution of genetic ancestries in positive, negative, and inconclusive cases by Kolmogorov-Smirnov tests and linear associations of ancestry with DY by Cochran-Armitage trend tests. We observed no reduction in overall DY associated with any genetic ancestry (African, Native American, East Asian, European, Middle Eastern, South Asian). However, we observed a relative increase in proportion of autosomal recessive homozygous inheritance versus other inheritance patterns associated with Middle Eastern and South Asian ancestry, due to consanguinity. In this empirical study of ES for undiagnosed pediatric and prenatal genetic conditions, genetic ancestry was not associated with the likelihood of a positive diagnosis, supporting the equitable use of ES in diagnosis of previously undiagnosed but potentially Mendelian disorders across all ancestral populations.

Prenatal vs postnatal diagnosis of 22q11.2 deletion syndrome: cardiac and noncardiac outcomes through 1 year of age.

BACKGROUND: The 22q11.2 deletion syndrome is the most common microdeletion syndrome and is frequently associated with congenital heart disease. Prenatal diagnosis of 22q11.2 deletion syndrome is increasingly offered. It is unknown whether there is a clinical benefit to prenatal detection as compared with postnatal diagnosis. OBJECTIVE: This study aimed to determine differences in perinatal and infant outcomes between patients with prenatal and postnatal diagnosis of 22q11.2 deletion syndrome. STUDY DESIGN: This was a retrospective cohort study across multiple international centers (30 sites, 4 continents) from 2006 to 2019. Participants were fetuses, neonates, or infants with a genetic diagnosis of 22q11.2 deletion syndrome by 1 year of age with or without congenital heart disease; those with prenatal diagnosis or suspicion (suggestive ultrasound findings and/or high-risk cell-free fetal DNA screen for 22q11.2 deletion syndrome with postnatal confirmation) were compared with those with postnatal diagnosis. Perinatal management, cardiac and noncardiac morbidity, and mortality by 1 year were assessed. Outcomes were adjusted for presence of critical congenital heart disease, gestational age at birth, and site. RESULTS: A total of 625 fetuses, neonates, or infants with 22q11.2 deletion syndrome (53.4% male) were included: 259 fetuses were prenatally diagnosed (156 [60.2%] were live-born) and 122 neonates were prenatally suspected with postnatal confirmation, whereas 244 infants were postnatally diagnosed. In the live-born cohort (n=522), 1-year mortality was 5.9%, which did not differ between groups but differed by the presence of critical congenital heart disease (hazard ratio, 4.18; 95% confidence interval, 1.56-11.18; P<.001) and gestational age at birth (hazard ratio, 0.78 per week; 95% confidence interval, 0.69-0.89; P<.001). Adjusting for critical congenital heart disease and gestational age at birth, the prenatal cohort was less likely to deliver at a local community hospital (5.1% vs 38.2%; odds ratio, 0.11; 95% confidence interval, 0.06-0.23; P<.001), experience neonatal cardiac decompensation (1.3% vs 5.0%; odds ratio, 0.11; 95% confidence interval, 0.03-0.49; P=.004), or have failure to thrive by 1 year (43.4% vs 50.3%; odds ratio, 0.58; 95% confidence interval, 0.36-0.91; P=.019). CONCLUSION: Prenatal detection of 22q11.2 deletion syndrome was associated with improved delivery management and less cardiac and noncardiac morbidity, but not mortality, compared with postnatal detection.

The utility of gene sequencing in identifying an underlying genetic disorder in prenatally suspected lower urinary tract obstruction.

OBJECTIVE: Fetal megacystis generally presents as suspected lower urinary tract obstruction (LUTO), which is associated with severe perinatal morbidity. Genetic etiologies underlying LUTO or a LUTO-like initial presentation are poorly understood. Our objectives are to describe single gene etiologies in fetuses initially ascertained to have suspected LUTO and to elucidate genotype-phenotype correlations. METHODS: A retrospective case series of suspected fetal LUTO positive for a molecular diagnosis was collected from five centers in the Fetal Sequencing Consortium. Demographics, sonograms, genetic testing including variant classification, and delivery outcomes were abstracted. RESULTS: Seven cases of initially prenatally suspected LUTO-positive for a molecular diagnosis were identified. In no case was the final diagnosis established as urethral obstruction that is, LUTO. All variants were classified as likely pathogenic or pathogenic. Smooth muscle deficiencies involving the bladder wall and interfering with bladder emptying were identified in five cases: MYOCD (2), ACTG2 (2), and MYH11 (1). Other genitourinary and/or non-genitourinary malformations were seen in two cases involving KMT2D (1) and BBS10 (1). CONCLUSION: Our series illustrates the value of molecular diagnostics in the workup of fetuses who present with prenatally suspected LUTO but who may have a non-LUTO explanation for their prenatal ultrasound findings.

Monogenic conditions and central nervous system anomalies: A prospective study, systematic review and meta-analysis.

OBJECTIVES: Determine the incremental diagnostic yield of prenatal exome sequencing (pES) over chromosome microarray (CMA) or G-banding karyotype in fetuses with central nervous system (CNS) abnormalities. METHODS: Data were collected via electronic searches from January 2010 to April 2022 in MEDLINE, Cochrane, Web of Science and EMBASE. The NHS England prenatal exome cohort was also included. Incremental yield was calculated as a pooled value using a random-effects model. RESULTS: Thirty studies were included (n = 1583 cases). The incremental yield with pES for any CNS anomaly was 32% [95%CI 27%-36%; I2 = 72%]. Subgroup analysis revealed apparent incremental yields in; (a) isolated CNS anomalies; 27% [95%CI 19%-34%; I2 = 74%]; (b) single CNS anomaly; 16% [95% CI 10%-23%; I2 = 41%]; (c) more than one CNS anomaly; 31% [95% Cl 21%-40%; I2 = 56%]; and (d) the anatomical subtype with the most optimal yield was Type 1 malformation of cortical development, related to abnormal cell proliferation or apoptosis, incorporating microcephalies, megalencephalies and dysplasia; 40% (22%-57%; I2 = 68%). The commonest syndromes in isolated cases were Lissencephaly 3 and X-linked hydrocephalus. CONCLUSIONS: Prenatal exome sequencing provides a high incremental diagnostic yield in fetuses with CNS abnormalities with optimal yields in cases with multiple CNS anomalies, particularly those affecting the midline, posterior fossa and cortex.

Impact of high-risk prenatal screening results for 22q11.2 deletion syndrome on obstetric and neonatal management: Secondary analysis from the SMART study.

OBJECTIVE: One goal of prenatal genetic screening is to optimize perinatal care and improve infant outcomes. We sought to determine whether high-risk cfDNA screening for 22q11.2 deletion syndrome (22q11.2DS) affected prenatal or neonatal management. METHODS: This was a secondary analysis from the SMART study. Patients with high-risk cfDNA results for 22q11.2DS were compared with the low-risk cohort for pregnancy characteristics and obstetrical management. To assess differences in neonatal care, we compared high-risk neonates without prenatal genetic confirmation with a 1:1 matched low-risk cohort. RESULTS: Of 18,020 eligible participants enrolled between 2015 and 2019, 38 (0.21%) were high-risk and 17,982 (99.79%) were low-risk for 22q11.2DS by cfDNA screening. High-risk participants had more prenatal diagnostic testing (55.3%; 21/38 vs. 2.0%; 352/17,982, p < 0.001) and fetal echocardiography (76.9%; 10/13 vs. 19.6%; 10/51, p < 0.001). High-risk newborns without prenatal diagnostic testing had higher rates of neonatal genetic testing (46.2%; 6/13 vs. 0%; 0/51, P < 0.001), echocardiography (30.8%; 4/13 vs. 4.0%; 2/50, p = 0.013), evaluation of calcium levels (46.2%; 6/13 vs. 4.1%; 2/49, P < 0.001) and lymphocyte count (53.8%; 7/13 vs. 15.7%; 8/51, p = 0.008). CONCLUSIONS: High-risk screening results for 22q11.2DS were associated with higher rates of prenatal and neonatal diagnostic genetic testing and other 22q11.2DS-specific evaluations. However, these interventions were not universally performed, and >50% of high-risk infants were discharged without genetic testing, representing possible missed opportunities to improve outcomes for affected individuals.

Access to prenatal exome sequencing for fetal malformations: A qualitative landscape analysis in the US.

OBJECTIVE: There is increasing evidence supporting the clinical utility of next generation sequencing for identifying fetal genetic disorders. However, there are limited data on the demand for and accessibility of these tests, as well as payer coverage in the prenatal context. We sought to identify clinician perspectives on the utility of prenatal exome sequencing (ES) and on equitable access to genomic technologies for the care of pregnancies complicated by fetal structural anomalies. METHOD: We conducted two focus group discussions and six interviews with a total of 13 clinicians (11 genetic counselors; 2 Maternal Fetal Medicine/Geneticists) from U.S. academic centers and community clinics. RESULTS: Participants strongly supported ES for prenatal diagnostic testing in pregnancies with fetal structural anomalies. Participants emphasized the value of prenatal ES as an opportunity for a continuum of care before, during, and after a pregnancy, not solely as informing decisions about abortions. Cost and coverage of the test was the main access barrier, and research was the main pathway to access ES in academic centers. CONCLUSION: Further integrating the perspectives of additional key stakeholders are important for understanding clinical utility, developing policies and practices to address access barriers, and assuring equitable provision of prenatal diagnostic testing.

Perinatal Outcomes Associated With Management of Stage 1 Hypertension.

OBJECTIVE: To evaluate the association between maternal blood pressure (BP) below 130/80 mm Hg compared with 130-139/80-89 mm Hg and pregnancy outcomes. METHODS: We conducted a planned secondary analysis of CHAP (Chronic Hypertension and Pregnancy), an open label, multicenter, randomized controlled trial. Participants with mean BP below 140/90 mm Hg were grouped as below 130/80 mm Hg compared with 130-139/80-89 mm Hg by averaging postrandomization clinic BP throughout pregnancy. The primary composite outcome was preeclampsia with severe features, indicated preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The secondary outcome was small for gestational age (SGA). RESULTS: Of 2,408 patients in CHAP, 2,096 met study criteria; 1,328 had mean BP 130-139/80-89 mm Hg and 768 had mean BP below 130/80 mm Hg. Participants with mean BP below 130/80 mm Hg were more likely to be older, on antihypertensive medication, in the active treatment arm, and to have lower BP at enrollment. Mean clinic BP below 130/80 mm Hg was associated with lower frequency of the primary outcome (16.0% vs 35.8%, adjusted relative risk 0.45; 95% CI 0.38-0.54) as well as lower risk of severe preeclampsia and indicated birth before 35 weeks of gestation. There was no association with SGA. CONCLUSION: In pregnant patients with mild chronic hypertension, mean BP below 130/80 mm Hg was associated with improved pregnancy outcomes without increased risk of SGA. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02299414.

Systematic evaluation of genome sequencing for the diagnostic assessment of autism spectrum disorder and fetal structural anomalies.

Short-read genome sequencing (GS) holds the promise of becoming the primary diagnostic approach for the assessment of autism spectrum disorder (ASD) and fetal structural anomalies (FSAs). However, few studies have comprehensively evaluated its performance against current standard-of-care diagnostic tests: karyotype, chromosomal microarray (CMA), and exome sequencing (ES). To assess the clinical utility of GS, we compared its diagnostic yield against these three tests in 1,612 quartet families including an individual with ASD and in 295 prenatal families. Our GS analytic framework identified a diagnostic variant in 7.8% of ASD probands, almost 2-fold more than CMA (4.3%) and 3-fold more than ES (2.7%). However, when we systematically captured copy-number variants (CNVs) from the exome data, the diagnostic yield of ES (7.4%) was brought much closer to, but did not surpass, GS. Similarly, we estimated that GS could achieve an overall diagnostic yield of 46.1% in unselected FSAs, representing a 17.2% increased yield over karyotype, 14.1% over CMA, and 4.1% over ES with CNV calling or 36.1% increase without CNV discovery. Overall, GS provided an added diagnostic yield of 0.4% and 0.8% beyond the combination of all three standard-of-care tests in ASD and FSAs, respectively. This corresponded to nine GS unique diagnostic variants, including sequence variants in exons not captured by ES, structural variants (SVs) inaccessible to existing standard-of-care tests, and SVs where the resolution of GS changed variant classification. Overall, this large-scale evaluation demonstrated that GS significantly outperforms each individual standard-of-care test while also outperforming the combination of all three tests, thus warranting consideration as the first-tier diagnostic approach for the assessment of ASD and FSAs.

Spectrum of Fetal Intraparenchymal Hemorrhage in COL4A1/A2-Related Disorders.

BACKGROUND: COL4A1/A2 variants affecting the alpha 1 and 2 chains of type IV collagen are increasingly recognized as a cause of fetal and neonatal intracranial hemorrhage, porencephaly, and schizencephaly. Fetal magnetic resonance imaging (MRI) findings in COL4A1/A2-related disorders are not well characterized. METHODS: This is a retrospective case series of fetal MRI findings in eight patients with intraparenchymal hemorrhage (IPH) and COL4A1/A2 variants, five of whom have postnatal imaging and clinical follow-up. RESULTS: IPH was multifocal and bilateral in four of eight patients. IPH involved the frontal lobes in all cases and basal ganglia in six of eight. The median maximum diameter of IPH was 16 mm (range 6 to 65 mm). All patients had ventriculomegaly, and four of eight had intraventricular hemorrhage. Prenatal IPH size correlated clinically with motor outcomes, and none had clinically symptomatic recurrent hemorrhage. CONCLUSION: COL4A1/A2 variants can present with a spectrum of IPH prenatally, including small and/or unifocal IPH, as well as multifocal and bilateral IPH, involving the frontal lobes and basal ganglia. Given the wide spectrum of IPH severity seen on fetal brain MRI, genetic testing for COL4A1/A2 variants should be considered in all cases of fetal IPH.

Cell-free DNA Screening for Aneuploidy.

Cell-free DNA (cfDNA) screening has high detection for the common fetal autosomal aneuploidies, but is not diagnostic. The positive predictive value should be utilized in counseling after a positive cell-free DNA screen, and diagnostic testing should be offered for confirmation. cfDNA screening does not report a result in ~3% of cases; nonreportable results indicate an increased risk for aneuploidy and some adverse perinatal outcomes. False-positive cfDNA screening occurs due to confined placental mosaicism, maternal copy number variants, mosaicism, and cancer. Pretest education and counseling should be provided with emphasis on the potential benefits, risks, and limitations before cfDNA screening.

Breastfeeding initiation and duration among people with mild chronic hypertension: a secondary analysis of the Chronic Hypertension and Pregnancy trial.

BACKGROUND: Increased duration of breastfeeding improves maternal cardiovascular health and may be especially beneficial in high-risk populations, such as those with chronic hypertension. Others have shown that individuals with hypertension are less likely to breastfeed, and there has been limited research aimed at supporting breastfeeding goals in this population. The impact of perinatal blood pressure control on breastfeeding outcomes among people with chronic hypertension is unknown. OBJECTIVE: This study aimed to evaluate whether breastfeeding initiation and short-term duration assessed at the postpartum clinic visit differed according to perinatal blood pressure treatment strategy (targeting blood pressure <140/90 mm Hg vs reserving antihypertensive treatment for blood pressure ≥160/105 mm Hg). STUDY DESIGN: We performed a secondary analysis of the Chronic Hypertension and Pregnancy trial. This was an open-label, multicenter, randomized trial where pregnant participants with mild chronic hypertension were randomized to receive antihypertensive medications with goal blood pressure <140/90 mm Hg (active treatment) or deferred treatment until blood pressure ≥160/105 mm Hg (control). The primary outcome was initiation and duration of breastfeeding, assessed at the postpartum clinic visit. We performed bivariate analyses and log-binomial and cumulative logit regression models, adjusting models for variables that were unbalanced in bivariate analyses. We performed additional analyses to explore the relationship between breastfeeding duration and blood pressure measurements at the postpartum visit. RESULTS: Of the 2408 participants from the Chronic Hypertension and Pregnancy trial, 1444 (60%) attended the postpartum study visit and provided breastfeeding information. Participants in the active treatment group had different body mass index class distribution and earlier gestational age at enrollment, and (by design) were more often discharged on antihypertensives. Breastfeeding outcomes did not differ significantly by treatment group. In the active and control treatment groups, 563 (77.5%) and 561 (78.1%) initiated breastfeeding, and mean durations of breastfeeding were 6.5±2.3 and 6.3±2.1 weeks, respectively. The probability of ever breastfeeding (adjusted relative risk, 0.99; 95% confidence interval, 0.93-1.05), current breastfeeding at postpartum visit (adjusted relative risk, 1.01; 95% confidence interval, 0.94-1.10), and weeks of breastfeeding (adjusted odds ratio, 0.87; 95% confidence interval, 0.68-1.12) did not differ by treatment group. Increased duration (≥2 vs <2 weeks) of breastfeeding was associated with slightly lower blood pressure measurements at the postpartum visit, but these differences were not significant in adjusted models. CONCLUSION: In a secondary analysis of the cohort of Chronic Hypertension and Pregnancy trial participants who attended the postpartum study visit and provided breastfeeding information (60% of original trial participants), breastfeeding outcomes did not differ significantly by treatment group. This suggests that maintaining goal blood pressure <140/90 mm Hg throughout the perinatal period is associated with neither harm nor benefit for short-term breastfeeding goals. Further study is needed to understand long-term breastfeeding outcomes among individuals with chronic hypertension and how to support this population in achieving their breastfeeding goals.

Parent-Reported Clinical Utility of Pediatric Genomic Sequencing.

BACKGROUND AND OBJECTIVES: Genomic sequencing (GS) is increasingly used for diagnostic evaluation, yet follow-up care is not well understood. We assessed clinicians' recommendations after GS, parent-reported follow-up, and actions parents initiated in response to learning their child's GS results. METHODS: We surveyed parents of children who received GS through the Clinical Sequencing Evidence Generating Research consortium ∼5 to 7 months after return of results. We compared the proportion of parents who reported discussing their child's result with a clinician, clinicians' recommendations, and parents' follow-up actions by GS result type using χ2 tests. RESULTS: A total of 1188 respondents completed survey measures on recommended medical actions (n = 1187) and/or parent-initiated actions (n = 913). Most parents who completed recommended medical actions questions (n = 833, 70.3%) reported having discussed their child's GS results with clinicians. Clinicians made recommendations to change current care for patients with positive GS results (n = 79, 39.1%) more frequently than for those with inconclusive (n = 31, 12.4%) or negative results (n = 44, 11.9%; P < .001). Many parents discussed (n = 152 completed, n = 135 planned) implications of GS results for future pregnancies with a clinician. Aside from clinical recommendations, 13.0% (n = 119) of parents initiated changes to their child's health or lifestyle. CONCLUSIONS: In diverse pediatric clinical contexts, GS results can lead to recommendations for follow-up care, but they likely do not prompt large increases in the quantity of care received.

Diagnostic Yield of Exome Sequencing in a Diverse Pediatric and Prenatal Population is not Associated with Genetic Ancestry.

Purpose: It has been hypothesized that diagnostic yield (DY) from Exome Sequencing (ES) may be lower among patients with non-European ancestries than those with European ancestry. We examined the association of DY with estimated continental genetic ancestry in a racially/ethnically diverse pediatric and prenatal clinical cohort. Methods: Cases (N=845) with suspected genetic disorders underwent ES for diagnosis. Continental genetic ancestry proportions were estimated from the ES data. We compared the distribution of genetic ancestries in positive, negative, and inconclusive cases by Kolmogorov Smirnov tests and linear associations of ancestry with DY by Cochran-Armitage trend tests. Results: We observed no reduction in overall DY associated with any continental genetic ancestry (Africa, America, East Asia, Europe, Middle East, South Asia). However, we observed a relative increase in proportion of autosomal recessive homozygous inheritance versus other inheritance patterns associated with Middle Eastern and South Asian ancestry, due to consanguinity. Conclusions: In this empirical study of ES for undiagnosed pediatric and prenatal genetic conditions, genetic ancestry was not associated with the likelihood of a positive diagnosis, supporting the ethical and equitable use of ES in diagnosis of previously undiagnosed but potentially Mendelian disorders across all ancestral populations.

Performance of prenatal cfDNA screening for sex chromosomes.

PURPOSE: The aim of this study was to assess the performance of cell-free DNA (cfDNA) screening to detect sex chromosome aneuploidies (SCAs) in an unselected obstetrical population with genetic confirmation. METHODS: This was a planned secondary analysis of the multicenter, prospective SNP-based Microdeletion and Aneuploidy RegisTry (SMART) study. Patients receiving cfDNA results for autosomal aneuploidies and who had confirmatory genetic results for the relevant sex chromosomal aneuploidies were included. Screening performance for SCAs, including monosomy X (MX) and the sex chromosome trisomies (SCT: 47,XXX; 47,XXY; 47,XYY) was determined. Fetal sex concordance between cfDNA and genetic screening was also evaluated in euploid pregnancies. RESULTS: A total of 17,538 cases met inclusion criteria. Performance of cfDNA for MX, SCTs, and fetal sex was determined in 17,297, 10,333, and 14,486 pregnancies, respectively. Sensitivity, specificity, and positive predictive value (PPV) of cfDNA were 83.3%, 99.9%, and 22.7% for MX and 70.4%, 99.9%, and 82.6%, respectively, for the combined SCTs. The accuracy of fetal sex prediction by cfDNA was 100%. CONCLUSION: Screening performance of cfDNA for SCAs is comparable to that reported in other studies. The PPV for the SCTs was similar to the autosomal trisomies, whereas the PPV for MX was substantially lower. No discordance in fetal sex was observed between cfDNA and postnatal genetic screening in euploid pregnancies. These data will assist interpretation and counseling for cfDNA results for sex chromosomes.