Preexisting maternal immunity to AAV but not Cas9 impairs in utero gene editing in mice.

In utero gene editing (IUGE) is a potential treatment for inherited diseases that cause pathology before or soon after birth. Preexisting immunity to adeno-associated virus (AAV) vectors and Cas9 endonuclease may limit postnatal gene editing. The tolerogenic fetal immune system minimizes a fetal immune barrier to IUGE. However, the ability of maternal immunity to limit fetal gene editing remains a question. We investigated whether preexisting maternal immunity to AAV or Cas9 impairs IUGE. Using a combination of fluorescent reporter mice and a murine model of a metabolic liver disease, we demonstrated that maternal anti-AAV IgG antibodies were efficiently transferred from dam to fetus and impaired IUGE in a maternal titer-dependent fashion. By contrast, maternal cellular immunity was inefficiently transferred to the fetus, and neither maternal cellular nor humoral immunity to Cas9 impaired IUGE. Using human umbilical cord and maternal blood samples collected from mid- to late-gestation pregnancies, we demonstrated that maternal-fetal transmission of anti-AAV IgG was inefficient in midgestation compared with term, suggesting that the maternal immune barrier to clinical IUGE would be less relevant at midgestation. These findings support immunologic advantages for IUGE and inform maternal preprocedural testing protocols and exclusion criteria for future clinical trials.

Optimal Timing of Delivery for Pregnant Individuals With Mild Chronic Hypertension.

OBJECTIVE: To investigate the optimal gestational age to deliver pregnant people with chronic hypertension to improve perinatal outcomes. METHODS: We conducted a planned secondary analysis of a randomized controlled trial of chronic hypertension treatment to different blood pressure goals. Participants with term, singleton gestations were included. Those with fetal anomalies and those with a diagnosis of preeclampsia before 37 weeks of gestation were excluded. The primary maternal composite outcome included death, serious morbidity (heart failure, stroke, encephalopathy, myocardial infarction, pulmonary edema, intensive care unit admission, intubation, renal failure), preeclampsia with severe features, hemorrhage requiring blood transfusion, or abruption. The primary neonatal outcome included fetal or neonatal death, respiratory support beyond oxygen mask, Apgar score less than 3 at 5 minutes, neonatal seizures, or suspected sepsis. Secondary outcomes included intrapartum cesarean birth, length of stay, neonatal intensive care unit admission, respiratory distress syndrome (RDS), transient tachypnea of the newborn, and hypoglycemia. Those with a planned delivery were compared with those expectantly managed at each gestational week. Adjusted odds ratios (aORs) with 95% CIs are reported. RESULTS: We included 1,417 participants with mild chronic hypertension; 305 (21.5%) with a new diagnosis in pregnancy and 1,112 (78.5%) with known preexisting hypertension. Groups differed by body mass index (BMI) and preexisting diabetes. In adjusted models, there was no association between planned delivery and the primary maternal or neonatal composite outcome in any gestational age week compared with expectant management. Planned delivery at 37 weeks of gestation was associated with RDS (7.9% vs 3.0%, aOR 2.70, 95% CI, 1.40-5.22), and planned delivery at 37 and 38 weeks was associated with neonatal hypoglycemia (19.4% vs 10.7%, aOR 1.97, 95% CI, 1.27-3.08 in week 37; 14.4% vs 7.7%, aOR 1.82, 95% CI, 1.06-3.10 in week 38). CONCLUSION: Planned delivery in the early-term period compared with expectant management was not associated with a reduction in adverse maternal outcomes. However, it was associated with increased odds of some neonatal complications. Delivery timing for individuals with mild chronic hypertension should weigh maternal and neonatal outcomes in each gestational week but may be optimized by delivery at 39 weeks.

Pregnancy Outcomes of Nifedipine Compared With Labetalol for Oral Treatment of Mild Chronic Hypertension.

OBJECTIVE: To evaluate maternal and neonatal outcomes by type of antihypertensive used in participants of the CHAP (Chronic Hypertension in Pregnancy) trial. METHODS: We conducted a planned secondary analysis of CHAP, an open-label, multicenter, randomized trial of antihypertensive treatment compared with standard care (no treatment unless severe hypertension developed) in pregnant patients with mild chronic hypertension (blood pressure 140-159/90-104 mm Hg before 20 weeks of gestation) and singleton pregnancies. We performed three comparisons based on medications prescribed at enrollment: labetalol compared with standard care, nifedipine compared with standard care, and labetalol compared with nifedipine. Although active compared with standard care groups were randomized, medication assignment within the active treatment group was not random but based on clinician or patient preference. The primary outcome was the occurrence of superimposed preeclampsia with severe features, preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The key secondary outcome was small for gestational age (SGA) neonates. We also compared medication adverse effects between groups. Relative risks (RRs) and 95% CIs were estimated with log binomial regression to adjust for confounding. RESULTS: Of 2,292 participants analyzed, 720 (31.4%) received labetalol, 417 (18.2%) received nifedipine, and 1,155 (50.4%) received no treatment. The mean gestational age at enrollment was 10.5±3.7 weeks; nearly half of participants (47.5%) identified as non-Hispanic Black; and 44.5% used aspirin. The primary outcome occurred in 217 (30.1%), 130 (31.2%), and 427 (37.0%) in the labetalol, nifedipine, and standard care groups, respectively. Risk of the primary outcome was lower among those receiving treatment (labetalol use vs standard adjusted RR 0.82, 95% CI, 0.72-0.94; nifedipine use vs standard adjusted RR 0.84, 95% CI, 0.71-0.99), but there was no significant difference in risk when labetalol was compared with nifedipine (adjusted RR 0.98, 95% CI, 0.82-1.18). There were no significant differences in SGA or serious adverse events between participants receiving labetalol and those receiving nifedipine. CONCLUSION: No significant differences in predetermined maternal or neonatal outcomes were detected on the basis of the use of labetalol or nifedipine for treatment of chronic hypertension in pregnancy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02299414.

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.

Clinical implications of crown-rump length discordance at 11 to 14 weeks in dichorionic twins.

BACKGROUND: Crown-rump length discordance, defined as ≥10% discordance, has been investigated as an early sonographic marker of subsequent growth abnormalities and is associated with an increased risk of fetal loss in twin pregnancies. Previous studies have not investigated the prevalence of fetal aneuploidy or structural anomalies in twins with discordance or the independent association of crown-rump length discordance with adverse perinatal outcomes. Moreover, data are limited on cell-free DNA screening for aneuploidy in dichorionic twins with discordance. OBJECTIVE: This study aimed to evaluate whether crown-rump length discordance in dichorionic twins between 11 and 14 weeks of gestation is associated with a higher risk of aneuploidy, structural anomalies, or adverse perinatal outcomes and to assess the performance of cell-free DNA screening in dichorionic twin pregnancies with crown-rump length discordance. STUDY DESIGN: This was a secondary analysis of a multicenter retrospective cohort study that evaluated the performance of cell-free DNA screening for the common trisomies in twin pregnancies from December 2011 to February 2020. For this secondary analysis, we included live dichorionic pregnancies with crown-rump length measurements between 11 and 14 weeks of gestation. First, we compared twin pregnancies with discordant crown-rump lengths with twin pregnancies with concordant crown-rump lengths and analyzed the prevalence of aneuploidy and fetal structural anomalies in either twin. Second, we compared the prevalence of a composite adverse perinatal outcome, which included preterm birth at <34 weeks of gestation, hypertensive disorders of pregnancy, stillbirth or miscarriage, small-for-gestational-age birthweight, and birthweight discordance. Moreover, we assessed the performance of cell-free DNA screening in pregnancies with and without crown-rump length discordance. Outcomes were compared with multivariable regression to adjust for confounders. RESULTS: Of 987 dichorionic twins, 142 (14%) had crown-rump length discordance. The prevalence of aneuploidy was higher in twins with crown-rump length discordance than in twins with concordance (9.9% vs 3.9%, respectively; adjusted relative risk, 2.7; 95% confidence interval, 1.4-4.9). Similarly, structural anomalies (adjusted relative risk, 2.5; 95% confidence interval, 1.4-4.4]) and composite adverse perinatal outcomes (adjusted relative risk, 1.2; 95% confidence interval, 1.04-1.3) were significantly higher in twins with discordance. A stratified analysis demonstrated that even without other ultrasound markers, there were increased risks of aneuploidy (adjusted relative risk, 3.5; 95% confidence interval, 1.5-8.4) and structural anomalies (adjusted relative risk, 2.7; 95% confidence interval, 1.5-4.8) in twins with CRL discordance. Cell-free DNA screening had high negative predictive values for trisomy 21, trisomy 18, and trisomy 13, regardless of crown-rump length discordance, with 1 false-negative for trisomy 21 in a twin pregnancy with discordance. CONCLUSION: Crown-rump length discordance in dichorionic twins is associated with an increased risk of aneuploidy, structural anomalies, and adverse perinatal outcomes, even without other sonographic abnormalities. Cell-free DNA screening demonstrated high sensitivity and negative predictive values irrespective of crown-rump length discordance; however, 1 false-negative result illustrated that there is a role for diagnostic testing. These data may prove useful in identifying twin pregnancies that may benefit from increased screening and surveillance and are not ascertained by other early sonographic markers.

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.

Connecting the dots: Carrier screening and the Genetic Information Nondiscrimination Act in the United States.

OBJECTIVE: To highlight the possibility of genetic discrimination in the United States with respect to carrier screening under limitations of the Genetic Information Nondiscrimination Act (GINA) and to encourage providers to educate patients about this possibility during pretest counseling. METHODS: Review of current professional guidelines and practice resources regarding the necessary components of pretest counseling for carrier screening in the context of GINA's limitations and the potential impact of carrier screening results on life, long-term care and disability insurance. RESULTS: Current practice resources advise that patients in the United States should be informed that their employer or health insurance company generally cannot use their genetic information during the underwriting process. However, these resources do not elaborate on GINA's limitations or explain why there may be adverse consequences to patients regarding these limitations. Studies have demonstrated significant gaps in provider knowledge of GINA, especially for those without formal genetic training. CONCLUSION: Enhanced education and provision of GINA educational resources for providers and patients will help ensure that patients have the opportunity to prioritize their insurance needs prior to undergoing carrier screening.

Prenatal Genetic Screening in Twin Pregnancy.

Twin pregnancy presents unique considerations for aneuploidy screening. Pre-test counseling regarding benefits, alternatives, and options for aneuploidy screening should be provided to all patients carrying twin pregnancy. This article aims to review the options for aneuploidy screening in twin pregnancy including the potential benefits and limitations.

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.

First Trimester Ultrasound and Aneuploidy Screening in Twins.

All patients with twin pregnancy should have first trimester ultrasound and be offered screening for chromosomal aneuploidy as well as diagnostic testing. Screening for aneuploidy in twins presents unique challenges compared with singletons. Cell-free DNA screening should be considered first-line; however, this option may not be available or may have limitations in certain clinical scenarios, such as vanishing twins. If cell-free DNA screening is not available, maternal serum marker screening in conjunction with nuchal translucency assessment should be offered. Patients with positive aneuploidy screening tests or fetal structural abnormalities should be offered diagnostic testing.

PROMPT: Prospective Meta-analysis for Pessary Trials Study Protocol.

OBJECTIVE: Preterm birth, defined as birth before 37 weeks of gestation, is a leading cause of perinatal and infant mortality throughout the world. Preterm birth is also associated with long-term neurological disabilities and other significant health issues in children. A short cervix in the second trimester has been noted to be one of the strongest predictors of subsequent spontaneous preterm birth in both singleton and multiple pregnancies. Some studies have shown that cervical support in the form of an Arabin pessary lowers the risk of preterm birth in women with a singleton gestation and short cervical length; however, other studies have conflicting results. Our objective was to form an international collaborative of planned or ongoing randomized trials of pessary in singleton and twin gestations with a short cervix. STUDY DESIGN: In November 2014, an international group of investigators, who had initiated or were planning randomized trials of pessary for pregnant people with a short cervix and singleton or twin gestation to prevent preterm birth, formed a collaboration to plan a prospective individual patient data (IPD) meta-analysis of randomized trials (PROspective Meta-analysis of Pessary Trials [PROMPT]). The PROMPT investigators agreed on meta-analysis IPD hypotheses for singletons and twins, eligibility criteria, and a set of core baseline and outcome measures. The primary outcome is a composite of fetal death or preterm delivery before 32 weeks' gestation. Secondary outcomes include maternal and neonatal morbidities. The PROMPT protocol may be viewed as a written agreement among the study investigators who make up the PROMPT consortium (PROSPERO ID# CRD42018067740). RESULTS: Results will be published in phases as the individual participating studies are concluded and published. Results of the first phase of singleton and twin pessary trials are expected to be available in late 2022. Updates are planned as participating trials are completed and published. KEY POINTS: · Short cervical length predicts preterm birth.. · Results of prior cervical pessary trials are mixed.. · Meta-analysis of pessary trials protocol..

Cervical Pessary for Prevention of Preterm Birth in Individuals With a Short Cervix: The TOPS Randomized Clinical Trial.

Importance: A short cervix as assessed by transvaginal ultrasound is an established risk factor for preterm birth. Study findings for a cervical pessary to prevent preterm delivery in singleton pregnancies with transvaginal ultrasound evidence of a short cervix have been conflicting. Objective: To determine if cervical pessary placement decreases the risk of preterm birth or fetal death prior to 37 weeks among individuals with a short cervix. Design, Setting, and Participants: We performed a multicenter, randomized, unmasked trial comparing a cervical pessary vs usual care from February 2017 through November 5, 2021, at 12 centers in the US. Study participants were nonlaboring individuals with a singleton pregnancy and a transvaginal ultrasound cervical length of 20 mm or less at gestations of 16 weeks 0 days through 23 weeks 6 days. Individuals with a prior spontaneous preterm birth were excluded. Interventions: Participants were randomized 1:1 to receive either a cervical pessary placed by a trained clinician (n = 280) or usual care (n = 264). Use of vaginal progesterone was at the discretion of treating clinicians. Main Outcome and Measures: The primary outcome was delivery or fetal death prior to 37 weeks. Results: A total of 544 participants (64%) of a planned sample size of 850 were enrolled in the study (mean age, 29.5 years [SD, 6 years]). Following the third interim analysis, study recruitment was stopped due to concern for fetal or neonatal/infant death as well as for futility. Baseline characteristics were balanced between participants randomized to pessary and those randomized to usual care; 98.9% received vaginal progesterone. In an as-randomized analysis, the primary outcome occurred in 127 participants (45.5%) randomized to pessary and 127 (45.6%) randomized to usual care (relative risk, 1.00; 95% CI, 0.83-1.20). Fetal or neonatal/infant death occurred in 13.3% of those randomized to receive a pessary and in 6.8% of those randomized to receive usual care (relative risk, 1.94; 95% CI, 1.13-3.32). Conclusions and Relevance: Cervical pessary in nonlaboring individuals with a singleton gestation and with a cervical length of 20 mm or less did not decrease the risk of preterm birth and was associated with a higher rate of fetal or neonatal/infant mortality. Trial Registration: ClinicalTrials.gov Identifier: NCT02901626.

Cell-free DNA screening for trisomy 21 in twin pregnancy: a large multicenter cohort study.

BACKGROUND: Analysis of cell-free DNA from maternal blood provides effective screening for trisomy 21 in singleton pregnancies. Data on cell-free DNA screening in twin gestations are promising although limited. In previous twin studies, cell-free DNA screening was primarily performed in the second trimester and many studies did not report chorionicity. OBJECTIVE: This study aimed to evaluate the screening performance of cell-free DNA for trisomy 21 in twin pregnancies in a large, diverse cohort. A secondary aim was to evaluate screening performance for trisomy 18 and trisomy 13. STUDY DESIGN: This was a retrospective cohort study of twin pregnancies from 17 centers for which cell-free DNA screening was performed from December 2011 to February 2020 by one laboratory using massively parallel sequencing technology. Medical record review was conducted for all newborns and data on the birth outcome, the presence of any congenital abnormalities, phenotypic appearance at birth, and any chromosomal testing that was undertaken in the antenatal or postnatal period were extracted. Cases with a possible fetal chromosomal abnormality with no genetic test results were reviewed by a committee of maternal-fetal medicine geneticists. Cases with a vanishing twin and inadequate follow-up information were excluded. A minimum of 35 confirmed cases of trisomy 21 was required to capture a sensitivity of at least 90% with a prevalence of at least 1.9% with 80% power. Test characteristics were calculated for each outcome. RESULTS: A total of 1764 samples were sent for twin cell-free DNA screening. Of those, 78 cases with a vanishing twin and 239 cases with inadequate follow-up were excluded, leaving a total of 1447 cases for inclusion in the analysis. The median maternal age was 35 years and the median gestational age at cell-free DNA testing was 12.3 weeks. In total, 81% of the twins were dichorionic. The median fetal fraction was 12.4%. Trisomy 21 was detected in 41 of 42 pregnancies, yielding a detection rate of 97.6% (95% confidence interval, 83.8-99.7). There was 1 false negative and no false positive cases. Trisomy 21 was detected in 38 out of 39 dichorionic twin pregnancies, yielding a detection rate of 97.4% (95% confidence interval, 82.6-99.7). Trisomy 18 was detected in 10 of the 10 affected pregnancies. There was 1 false positive case. Trisomy 13 was detected in 4 of the 5 cases, yielding a detection rate of 80% (95% confidence interval, 11.1-99.2). There was one false negative and no false positive cases. The nonreportable rate was low at 3.9 %. CONCLUSION: Cell-free DNA testing is effective in screening for trisomy 21 in twin gestations from the first trimester of pregnancy. Detection of trisomy 21 was high in dichorionic and monochorionic twins, and the nonreportable result rates were low. This study included high numbers of cases of trisomy 18 and 13 when compared with the current literature. Although screening for these conditions in twins seems to be promising, the numbers were too small to make definitive conclusions regarding the screening efficacy for these conditions. It is possible that cell-free DNA testing performance may differ among laboratories and vary with screening methodologies.

Outcomes of shared institutional review board compared with multiple individual site institutional review board models in a multisite clinical trial.

BACKGROUND: Institutional review boards play a crucial role in initiating clinical trials. Although many multicenter clinical trials use an individual institutional review board model, where each institution uses their local institutional review board, it is unknown if a shared (single institutional review board) model would reduce the time required to approve a standard institutional review board protocol. OBJECTIVE: This study aimed to compare processing times and other processing characteristics between sites using a single institutional review board model and those using their individual site institutional review board model in a multicenter clinical trial. STUDY DESIGN: This was a retrospective study of sites in an open-label, multicenter randomized control trial from 2014 to 2021. Participating sites in the multicenter Chronic Hypertension and Pregnancy trial were asked to complete a survey collecting data describing their institutional review board approval process. RESULTS: A total of 45 sites participated in the survey (7 used a shared institutional review board model and 38 used their individual institutional review board model). Most sites (86%) using the shared institutional review board model did not require a full-board institutional review board meeting before protocol approval, compared with 1 site (3%) using the individual institutional review board model (P<.001). Median total approval times (41 vs 56 days; P=.42), numbers of submission rounds (1 vs 2; P=.09), and numbers of institutional review board stipulations (1 vs 4; P=.12) were lower for the group using the shared institutional review board model than those using the individual site institutional review board model; however, these differences were not statistically significant. CONCLUSION: The findings supported the hypothesis that the shared institutional review board model for multicenter studies may be more efficient in terms of cumulative time and effort required to obtain approval of an institutional review board protocol than the individual institutional review board model. Given that these data have important implications for multicenter clinical trials, future research should evaluate these findings using larger or multiple multicenter trials.

How to choose a test for prenatal genetic diagnosis: a practical overview.

Establishing the diagnosis of a fetal genetic disease in utero expands decision-making opportunities for individuals during pregnancy and enables providers to tailor prenatal care and surveillance to disease-specific risks. The selection of prenatal genetic tests is guided by key details from fetal imaging, family and obstetrical history, suspected diagnoses and mechanisms of disease, an accurate understanding of what abnormalities each test is designed to detect, and, at times, the gestational age at which testing is initiated. Pre- and posttest counseling, by or in conjunction with providers trained in genetics, ensure an accurate understanding of genetic tests, their potential results and limitations, estimated turnaround time for results, and the clinical implications of their findings. As prenatal diagnosis and testing options continue to expand rapidly, it is increasingly important for obstetrical providers to understand how to choose appropriate genetic testing and contextualize the clinical implications of their results.

Adverse Perinatal Outcomes Associated with Stage 1 Hypertension in Pregnancy: A Retrospective Cohort Study.

OBJECTIVE: To determine if women who newly met criteria for stage 1 hypertension in early pregnancy were at increased risk for adverse perinatal outcomes compared with normotensive women. STUDY DESIGN: We conducted a retrospective cohort study of women who had prenatal care at a single institution and subsequently delivered a live infant between December 2017 and August 2019. Women with a singleton gestation who had at least two prenatal visits prior to 20 weeks of gestation were included. We excluded women with known chronic hypertension or other major maternal illness. Two groups were identified: (1) women newly diagnosed with stage 1 hypertension before 20 weeks of gestation (blood pressure [BP]: 130-139/80-89 on at least two occasions) and (2) women with no known history of hypertension and normal BP (<130/80 mm Hg) before 20 weeks of gestation. The primary outcome was any hypertensive disorder of pregnancy; secondary outcomes were indicated preterm birth and small for gestational age. Generalized linear models were used to compare risk of adverse outcomes between the groups. RESULTS: Of the 1,630 women included in the analysis, 1,443 women were normotensive prior to 20 weeks of gestation and 187 women (11.5%) identified with stage 1 hypertension. Women with stage 1 hypertension were at significantly increased risk for any hypertensive disorder of pregnancy (adjusted risk ratio [aRR]: 1.86, 95% confidence interval [CI]: 1.12-3.04) and indicated preterm birth (aRR: 1.83, 95% CI: 1.12-3.02). Black women and obese women with stage 1 hypertension were at increased for hypertensive disorder of pregnancy compared with white women and nonobese women, respectively (aRR: 1.32, 95% CI: 1.11-1.57; aRR: 1.69, 95% CI: 1.39-2.06). CONCLUSION: These results provide insight about the prevalence of stage 1 hypertension and inform future guidelines for diagnosis and management of hypertension in pregnancy. Future research is needed to assess potential interventions to mitigate risk. KEY POINTS: · Stage 1 hypertension increased risk for hypertensive disorders of pregnancy and indicated preterm birth.. · Among women with stage 1 hypertension, risk of severe preeclampsia was 2.6 times higher than normotensive women.. · Black and obese women with stage 1 hypertension were at additional risk for adverse outcomes..

Guidelines for Cystic Fibrosis Carrier Screening in the Prenatal/Preconception Period.

Importance: Cystic fibrosis (CF) is one of the most common autosomal recessive disorders. Carrier screening for CF should be offered to all women considering becoming pregnant or who are pregnant. Understanding the available screening tests, their limitations, and the benefits of screening is of paramount importance to the obstetrician-gynecologist. Objectives: The objective is to review the current guidelines for CF carrier screening including the options for carrier screening, the potential complexities associated with carrier screening for CF, and indications for referral to certified genetic counselors or maternal-fetal medicine specialists. Evidence Acquisition: A MEDLINE search of "cystic fibrosis," "cystic fibrosis carrier screening pregnancy," and "inheritance of cystic fibrosis" in the review was performed. Results: The evidence cited in this review includes 2 medical society committee opinions and 15 additional peer-reviewed journal articles that were original research or expert opinion summaries. Conclusions and Relevance: The American College of Obstetricians and Gynecologists recommends that obstetricians offer CF carrier screening to all pregnant women or women considering becoming pregnant. Based on recent guidelines from ACMG, additional expanded carrier screening can be recommended to patients in the future, with additional CF variants and other autosomal or X-linked recessive conditions. It is important for the prenatal care provider to understand the guidelines for carrier screening as well as the potential complexities associated with carrier screening due to the multiple pathogenic variants in the CFTR gene that may be associated with varying phenotypes. With the options for CF carrier screening, screening performance in different populations, a basic understanding of the disease and interpretation of carrier screening results is of paramount importance to the prenatal care provider.