Availability Versus Accessibility: Identifying COVID-19 Testing Deserts Across Massachusetts.

Throughout the COVID-19 pandemic, communities of color have faced significantly higher rates of COVID-19 infection, as well as poor clinical outcomes. These differences are driven by long-standing structural inequities that prevent effective social distancing efforts and are further exacerbated by disparities in COVID-19 testing. Our study applied the concept of "COVID-19 testing deserts" to systematically identify gaps in testing resource allocation across Massachusetts in May 2020 and March 2021. Testing deserts were identified at the census tract level, using criteria developed by the Department of Agriculture for food deserts. Testing deserts occurred more frequently in segregated Hispanic, segregated Black, mixed minority, and integrated communities, as well as in neighborhoods with low vehicle access and in federally designated Medically Underserved Areas. Segregated communities were those in which more than 50 percent of the population self-identified as non-Hispanic White, Hispanic, non-Hispanic Black, or non-Hispanic Asian, respectively. Testing deserts were overrepresented in counties with high COVID-19 incidence rates, suggesting that testing accessibility is essential for prompt COVID-19 diagnosis and self-isolation.

Factors Associated With Coronavirus Disease 2019 Vaccine Uptake Among Pregnant Women and Nonpregnant Women of Reproductive Age in Jamaica.

Background: Despite high rates of coronavirus disease 2019 (COVID-19)-related maternal mortality, Jamaica currently has little data on COVID-19 vaccine uptake among pregnant women. Methods: We conducted a cross-sectional, web-based survey of 192 reproductive-aged women in Jamaica from February 1 to 8, 2022. Participants were recruited from a convenience sample of patients, providers, and staff at a teaching hospital. We assessed self-reported COVID-19 vaccination status and COVID-19-related medical mistrust (operationalized as vaccine confidence, government mistrust, and race-based mistrust). We used multivariable modified Poisson regression to test the association between vaccine uptake and pregnancy. Results: Of 192 respondents, 72 (38%) were pregnant. Most (93%) were Black. Vaccine uptake was 35% in pregnant women versus 75% in nonpregnant women. Pregnant women were more likely to cite healthcare providers versus the government as trustworthy sources of COVID-19 vaccine information (65% vs 28%). Pregnancy, low vaccine confidence, and government mistrust were associated with a lower likelihood of COVID-19 vaccination (adjusted prevalence ratio [aPR] = 0.68 [95% confidence interval {CI}, .49-.95], aPR = 0.61 [95% CI, .40-.95], and aPR = 0.68 [95% CI, .52-.89], respectively). Race-based mistrust was not associated with COVID-19 vaccination in the final model. Conclusions: Pregnancy, low vaccine confidence, and government mistrust were associated with a lower likelihood of COVID-19 vaccination among reproductive-aged women in Jamaica. Future studies should evaluate the efficacy of strategies proven to improve maternal vaccination coverage, including standing "opt-out" vaccination orders and collaborative provider and patient-led educational videos tailored for pregnant individuals. Strategies that decouple vaccine messaging from government agencies also warrant evaluation.

Provider confidence in counseling preconception, pregnant, and postpartum patients regarding COVID-19 vaccination: A cross-sectional survey study.

Background and Aims: Healthcare provider counseling surrounding COVID-19 vaccine in pregnancy and lactation is essential to vaccination uptake in this population; however, provider knowledge and confidence are not well characterized. We aimed to assess knowledge and confidence in COVID-19 vaccine counseling among practitioners who provide care to pregnant persons and to describe factors associated with confidence in counseling. Methods: A web-based anonymous survey was distributed via email to a cross-sectional convenience sample of Obstetrics and Gynecology, Primary Care, and Internal Medicine faculty at three hospitals in a single healthcare network in Massachusetts, United States. Individual demographics and institution-specific variables were included in the survey along with questions assessing both attitudes toward COVID-19 illness and confidence in counseling regarding the use of the vaccine in pregnancy. Results: Almost all providers (151, 98.1%) reported that they received a COVID-19 vaccine, and most (111, 72.1%) reported that they believe the benefits of the vaccine in pregnancy outweigh the risks. Forty-one (26.6%) reported feeling very confident in counseling patients who primarily speak English about the evidence for messenger ribonucleic acid vaccination in pregnancy, and 36 (23%) reported feeling very confident in counseling patients who are not primarily English-speaking. Forty-three providers (28.1%) expressed strong confidence in their comfort talking to individuals with vaccine hesitancy based on historic and continued racism and systemic injustices. The sources that survey respondents most used to find information regarding COVID-19 vaccination in pregnancy were the Centers for Disease Control (112, 74.2%), hospital-specific resources (94, 62.3%), and the American College of Obstetricians and Gynecologists (82, 54.3%). Conclusion: Ensuring that providers feel comfortable bridging the gap between their belief that the vaccine is beneficial for pregnant patients and their comfort with holding conversations with patients regarding vaccination is paramount to ensure equitable access to vaccines for pregnant patients.

First Trimester Cardiac Biomarkers among Women with Peripartum Cardiomyopathy: Are There Early Clues to This Late-Pregnancy Phenomenon?

OBJECTIVE: Whether biomarkers may enable early identification of women who develop peripartum cardiomyopathy (PPCM) prior to disease onset remains a question of interest. STUDY DESIGN: A retrospective nested case-control study was conducted to determine whether first trimester N-terminal pro-B type natriuretic peptide (NT-proBNP) or high sensitivity cardiac troponin I (hs-cTnI) differed among women who developed PPCM versus unaffected pregnancies. Cases were matched to unaffected women by age, race, parity, and gestational age of sample (control A) and then further by blood pressure and pregnancy weight gain (control B). RESULTS: First trimester NT-proBNP concentrations were numerically higher among women who subsequently developed PPCM (116 pg/mL [83-177]) as compared with women in control A (56.1 pg/mL [38.7-118.7], p = 0.3) or control B (37.6 [23.3 - 53.8], p <0.05). A higher proportion of women who subsequently developed PPCM (50%) had detectable levels of hs-cTnI as compared with control A (0%, p = 0.03) or control B (18.8%, p = 0.52). Among both cases and controls, hs-cTnI values were low and often below the limit of detection. CONCLUSION: There were differences in first trimester NT-proBNP and hs-cTnI concentrations between women who subsequently developed PPCM and those who did not, raising the possibility the early pregnancy subclinical myocardial dysfunction may be associated with this late-pregnancy disease. KEY POINTS: · First trimester NT-proBNP is numerically higher among women who subsequently develop PPCM.. · First trimester hs-cTnI was nominally higher among women who developed PPCM versus those who did not.. · A significant proportion of normal pregnant women have undetectable hs-cTnI..

Experiences Navigating the Pregnancy Care Continuum During the COVID-19 Pandemic.

INTRODUCTION: The COVID-19 pandemic led to unprecedented changes in care delivery across the pregnancy care continuum. Our primary objective with this research was to characterize the range of ways that the early months of the COVID-19 pandemic affected pregnancy, childbirth, and postpartum care experiences. METHODS: Pregnant and recently pregnant patients (n = 20) from obstetrics and gynecology clinical sites associated with Massachusetts General Hospital were interviewed about their experiences with prenatal care, childbirth, and postpartum care during the first wave of the COVID-19 pandemic. Interview transcripts were analyzed for emergent themes. RESULTS: This sample included 20 pregnant and postpartum people, including 11 individuals who tested positive for COVID-19 during pregnancy or postpartum and nine with suspected infection. The ways in which COVID-19 or suspected COVID-19 affected experiences of prenatal care, childbirth, and postpartum care were complex and varied. Three themes were identified across narratives of pregnancy, birth, and postpartum care: patient perceptions of diminished access to care, stigma due to COVID-19 infection, and limited capacity of providers to honor patient preferences. CONCLUSIONS: A better understanding of pregnant and recently pregnant people's experiences during the early months of the COVID-19 pandemic can inform infection control policies and clinical care delivery practices that are more congruent with the needs and values of pregnant, birthing, and postpartum people as institutions craft responses to future pandemics. Approaches that maximize meaningful access across the pregnancy care continuum, center patients' priorities within adapted care models, and honor patient preferences as much as possible are important aspects of an appropriate response to future waves of COVID-19 and other pandemics.

Perceptions and Attitudes toward COVID-19 Vaccination among Pregnant and Postpartum Individuals.

OBJECTIVE: This study aimed to characterize attitudes toward novel coronavirus disease 2019 (COVID-19) vaccination and to evaluate factors associated with vaccine uptake among pregnant individuals. STUDY DESIGN: An anonymous survey was distributed to a convenience sample of pregnant individuals receiving prenatal care at two large urban academic hospitals in a single health care network in Massachusetts. Individual demographic variables were included in the survey along with questions assessing attitudes toward COVID-19 and vaccination in pregnancy. Data were analyzed using parametric or nonparametric tests when appropriate, and associated odds ratios (OR) were calculated via univariable logistic regression. RESULTS: There were 684 surveys distributed, and 477 pregnant and postpartum individuals completed the survey, for a response rate of 69.7%. Overall, 233 (49.3%) had received or were scheduled to receive a COVID-19 vaccine. Age, White race, non-Hispanic or Latinx ethnicity, working from home, and typical receipt of the influenza vaccine were associated with COVID-19 vaccination. Further, 276 respondents (58.4%) reported that their provider recommended the COVID-19 vaccine in pregnancy; these participants were more likely to have received a vaccine (OR = 5.82, 95% confidence interval [CI]: 3.68-9.26, p < 0.005). Vaccinated individuals were less likely to be worried about the effects of the vaccine on themselves (OR = 0.18, 95% CI: 0.12-0.27, p < 0.005) or their developing babies (OR = 0.17, 95% CI: 0.11-0.26, p < 0.005). Unvaccinated individuals were less likely to report that it is easy to schedule a COVID-19 vaccine (OR = 0.56, 95% CI: 0.34-0.93, p = 0.02), to travel to receive a vaccine (OR = 0.19, 95% CI: 0.10-0.36, p < 0.005), and to miss work to receive a vaccine (OR = 0.30, 95% CI: 0.18-0.48, p < 0.005). CONCLUSION: Strategies are needed to improve patient education regarding vaccine side effects and safety in pregnancy. Policy changes should focus on making it feasible for patients to schedule a vaccine and miss work without loss of pay to get vaccinated. KEY POINTS: · There were racial and ethnic disparities in COVID-19 vaccination.. · Unvaccinated respondents were more likely to be concerned about vaccine effects for themselves or their growing babies.. · Unvaccinated respondents cited work and scheduling-related barriers to vaccination, indicating areas for advocacy..

Maternal immune response and placental antibody transfer after COVID-19 vaccination across trimester and platforms.

The availability of three COVID-19 vaccines in the United States provides an unprecedented opportunity to examine how vaccine platforms and timing of vaccination in pregnancy impact maternal and neonatal immunity. Here, we characterize the antibody profile after Ad26.COV2.S, mRNA-1273 or BNT162b2 vaccination in 158 pregnant individuals and evaluate transplacental antibody transfer by profiling maternal and umbilical cord blood in 175 maternal-neonatal dyads. These analyses reveal lower vaccine-induced functions and Fc receptor-binding after Ad26.COV2.S compared to mRNA vaccination and subtle advantages in titer and function with mRNA-1273 versus BN162b2. mRNA vaccines have higher titers and functions against SARS-CoV-2 variants of concern. First and third trimester vaccination results in enhanced maternal antibody-dependent NK-cell activation, cellular and neutrophil phagocytosis, and complement deposition relative to second trimester. Higher transplacental transfer ratios following first and second trimester vaccination may reflect placental compensation for waning maternal titers. These results provide novel insight into the impact of platform and trimester of vaccination on maternal humoral immune response and transplacental antibody transfer.

Emotional Experiences of Pregnant and Postpartum People with Confirmed or Suspected COVID-19 Infection During the Initial Surge of the Pandemic.

Objectives: The COVID-19 pandemic may have a unique emotional impact on pregnant people. This qualitative study aimed to characterize the emotional effects of the COVID-19 pandemic on pregnant and recently pregnant patients who had either suspected or confirmed COVID-19 infection during the initial 6 months of the pandemic. Methods: Pregnant and recently pregnant participants (n = 20) from Massachusetts General Hospital Obstetrics and Gynecology clinical sites with suspected or confirmed COVID-19 infection were interviewed about their experiences during the COVID-19 pandemic. Interviews were transcribed and coded using NVivo 12 software. Using data display matrices, thematic analysis was performed to identify emergent, crosscutting themes. Results: Twenty pregnant and postpartum patients participated of whom 12 had confirmed COVID-19 infection and 8 had suspected infection. The most frequently described emotions were anxiety (90%), uncertainty (80%), fear (70%), relief (65%), and sadness (60%). The following three crosscutting themes were identified: risk, protection, and change. The ways in which participants articulated their emotional reactions to the themes of risk, protection, and change were complex and varied. Conclusions: There was a broad range of negative and positive emotional experiences of pregnancy, birth, and the postpartum period during the first 4 months of the COVID-19 pandemic. A better understanding of pregnant people's emotional experiences may lead to changes in clinical practice and institutional policies that are more supportive of their needs and congruent with their values.

Prolonged Second Stage of Labor and Anal Sphincter Injury in a Contemporary Cohort of Term Nulliparas.

OBJECTIVE: This study aimed to assess whether a prolonged second stage of labor is an independent predictor of obstetric anal sphincter injury (OASI) in a contemporary cohort of nulliparous and term parturients, and to evaluate whether predelivery factors can accurately predict OASI. STUDY DESIGN: This was a nested case-control study within a cohort of consecutive nulliparous term parturients with a singleton gestation who underwent a vaginal delivery at a single institution between January 2014 and January 2015. Cases were defined as women with a third- or fourth-degree laceration at the time of delivery, and controls were women without a third- or fourth-degree laceration. A prolonged second stage was defined as a second stage of ≥3 hours. Univariable and multivariable regression analyses were performed to examine the relationship between prolonged second stage of labor and third- or fourth-degree lacerations. Receiver operator curves were developed to assess the predictive capacity of predelivery information for third- and fourth-degree lacerations. RESULTS: Of 1,197 births, 63 women had third- or fourth-degree lacerations (5.3%). With each additional hour of the second stage, the rate of OASI increased, with 2.9% of women with a second stage of <1 hour with OASI, 3.5% between 1 and 2 hours, 5.7% between 2 and 3 hours, 7.8% between 3 and 4 hours, 16.1% between 4 and 5 hours, and 28.6% among women with a second stage length >5 hours (p < 0.001). In multivariable regression analysis, operative vaginal delivery (adjusted odds ratio [aOR] = 5.92, 95% confidence interval [CI]: 3.17-11.07) and a prolonged second stage (aOR = 1.92, 95% CI: 1.06-3.51) were independent predictors of third- and fourth-degree lacerations. A predictive model was developed from these results (area under the curve [AUC] = 0.75, 95% CI: 0.68-0.81). CONCLUSION: Prolonged second stage of labor is a predictor of OASI, after adjustment for operative vaginal delivery. A model using predelivery risk factors has a reasonable prediction of OASI. KEY POINTS: · Prolonged second stage labor is associated with obstetric anal sphincter injury in term nulliparas.. · Predelivery risk factors reasonably predict obstetric anal sphincter injury in term nulliparas.. · Improved models are needed for clinical risk-stratification..

Pregnant Individuals' Views on Fetal Tissue Research in the United States.

OBJECTIVE: Fetal tissue research has driven significant medical advances but remains publicly contentious in the United States. The views of pregnant individuals in the United States regarding the donation of fetal tissue offer an important and previously unexplored perspective on this issue. METHODS: We conducted a secondary analysis of data from two separate, broader qualitative studies. Pregnant and recently pregnant individuals (N=79) from clinical sites at the University of North Carolina at Chapel Hill, Johns Hopkins University, and Massachusetts General Hospital were interviewed individually using a semi-structured guide addressing a range of issues related to infectious disease research and pregnancy, including the acceptability of fetal tissue research. Interviews were transcribed, coded, and analyzed for emergent themes. RESULTS: Among this sample of predominantly Black (61%), reproductive-aged pregnant and recently pregnant participants, the majority (72%) generally supported fetal tissue research. The following three themes were identified: choice, respect, and meaning. Respondents discussed the deeply personal nature of decisions surrounding fetal tissue research, emphasizing the importance of informed consent and respect for the person's emotional state when approaching for consent. The ways in which participants regarded how to respectfully handle fetal tissue also shaped views about the acceptability of donation, both for and against. For many participants, fetal tissue donation to research represented one way of ascribing meaning to pregnancy termination or loss. CONCLUSION: Among this diverse sample of pregnant and recently pregnant individuals, most were supportive of fetal tissue donation for research. A better understanding of pregnant individuals' views on this topic may lead to policies and practices that are congruent with the needs and values of people facing decisions regarding the disposition of fetal remains.

Advancing research in pregnancy during COVID-19: Missed opportunities and momentum in the US.

Pregnant people's exclusion from COVID-19 vaccine research highlights both the harms of excluding pregnant people from clinical trials and the growing public support for their equitable inclusion. Protectionary tendencies must be challenged for the sake of progress. The COVID-19 pandemic presents an opportunity to translate recognition of an unjust paradigm into action.

Third trimester stillbirth during the first wave of the SARS-CoV-2 pandemic: Similar rates with increase in placental vasculopathic pathology.

Whether early SARS-CoV-2 definitively increases the risk of stillbirth is unknown, though studies have suggested possible trends of stillbirth increase during the pandemic. This study of third trimester stillbirth does not identify an increase in rates during the first wave of the pandemic period, however investigation of the placental pathology demonstrates trends towards more vascular placental abnormalities.

Patient characteristics associated with SARS-CoV-2 infection in parturients admitted for labour and delivery in Massachusetts during the spring 2020 surge: A prospective cohort study.

BACKGROUND: While studies from large cities affected by coronavirus disease 2019 (COVID-19) have reported on the prevalence of SARS-CoV-2 in the context of universal testing during admission for delivery, the patient demographic, social and clinical factors associated with SARS-CoV-2 infection in pregnant women are not fully understood. OBJECTIVE: To evaluate the epidemiological factors associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in women admitted for labour and delivery, in the context of universal screening at four Boston-area hospitals. METHODS: In this prospective cohort study, we reviewed the health records of all women admitted for labour and delivery at four hospitals from the largest health system in Massachusetts between 19 April 2020 and 27 June 2020. We calculated the risk of SARS-CoV-2 infection, including asymptomatic infection. We calculated associations between SARS-CoV-2 infection and demographic and clinical characteristics. RESULTS: A total of 93 patients (3.2%, 95% confidence interval 2.5, 3.8) tested positive for SARS-CoV-2 infection on admission for labour and delivery out of 2945 patients included in the analysis; 80 (86.0%) of the patients who tested positive were asymptomatic at the time of testing. Factors associated with SARS-CoV-2 infection included the following: younger age, obesity, African American or Hispanic race/ethnicity, residence in heavily affected communities (as measured in cases reported per capita), presence of a household member with known SARS-CoV-2 infection, non-health care essential worker occupation and MassHealth or Medicaid insurance compared to commercial insurance. 93.8% of patients testing positive for SARS-CoV-2 on admission had one or more identifiable factors associated with disease acquisition. CONCLUSIONS: In this large sample of deliveries during the height of the surge in infections during the spring of 2020, SARS-CoV-2 infection was largely concentrated in patients with distinct demographic characteristics, those largely from disadvantaged communities. Racial disparities seen in pregnancy persist with respect to SARS-CoV-2 infection.

Compromised SARS-CoV-2-specific placental antibody transfer.

SARS-CoV-2 infection causes more severe disease in pregnant women compared to age-matched non-pregnant women. Whether maternal infection causes changes in the transfer of immunity to infants remains unclear. Maternal infections have previously been associated with compromised placental antibody transfer, but the mechanism underlying this compromised transfer is not established. Here, we used systems serology to characterize the Fc profile of influenza-, pertussis-, and SARS-CoV-2-specific antibodies transferred across the placenta. Influenza- and pertussis-specific antibodies were actively transferred. However, SARS-CoV-2-specific antibody transfer was significantly reduced compared to influenza- and pertussis-specific antibodies, and cord titers and functional activity were lower than in maternal plasma. This effect was only observed in third-trimester infection. SARS-CoV-2-specific transfer was linked to altered SARS-CoV-2-antibody glycosylation profiles and was partially rescued by infection-induced increases in IgG and increased FCGR3A placental expression. These results point to unexpected compensatory mechanisms to boost immunity in neonates, providing insights for maternal vaccine design.

Compassionate Use of Remdesivir in Pregnant Women With Severe Coronavirus Disease 2019.

BACKGROUND: Remdesivir is efficacious for severe coronavirus disease 2019 (COVID-19) in adults, but data in pregnant women are limited. We describe outcomes in the first 86 pregnant women with severe COVID-19 who were treated with remdesivir. METHODS: The reported data span 21 March to 16 June 2020 for hospitalized pregnant women with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 infection and room air oxygen saturation ≤94% whose clinicians requested remdesivir through the compassionate use program. The intended remdesivir treatment course was 10 days (200 mg on day 1, followed by 100 mg for days 2-10, given intravenously). RESULTS: Nineteen of 86 women delivered before their first dose and were reclassified as immediate "postpartum" (median postpartum day 1 [range, 0-3]). At baseline, 40% of pregnant women (median gestational age, 28 weeks) required invasive ventilation, in contrast to 95% of postpartum women (median gestational age at delivery 30 weeks). By day 28 of follow-up, the level of oxygen requirement decreased in 96% and 89% of pregnant and postpartum women, respectively. Among pregnant women, 93% of those on mechanical ventilation were extubated, 93% recovered, and 90% were discharged. Among postpartum women, 89% were extubated, 89% recovered, and 84% were discharged. Remdesivir was well tolerated, with a low incidence of serious adverse events (AEs) (16%). Most AEs were related to pregnancy and underlying disease; most laboratory abnormalities were grade 1 or 2. There was 1 maternal death attributed to underlying disease and no neonatal deaths. CONCLUSIONS: Among 86 pregnant and postpartum women with severe COVID-19 who received compassionate-use remdesivir, recovery rates were high, with a low rate of serious AEs.

Establishing Better Evidence on Remote Monitoring for Postpartum Hypertension: A Silver Lining of the Coronavirus Pandemic.

The transformation of our health care system in response to coronavirus disease 2019 (COVID-19) provides a unique opportunity to examine the use of telehealth for postpartum care. The postpartum period can pose significant risks and challenges, particularly for women with hypertensive disorders of pregnancy. Remote blood pressure monitoring has proven feasible and acceptable among women and providers but has not been widely implemented or researched. Early studies have identified improved outcomes with use of telehealth, including increased compliance with care and decreased disparity in hypertension follow-up. Preliminary data make a compelling case for remote monitoring as a promising treatment strategy to manage postpartum hypertension. Remote monitoring technology should be incorporated as a standard component for the comprehensive management of postpartum hypertension during COVID-19. As a consequence of the pandemic, we now have an opportunity to research the impact of postpartum remote blood pressure monitoring on maternal outcome and disparities within these outcomes.

Congenital thrombotic thrombocytopenic purpura (TTP) with placental abruption despite maternal improvement: a case report.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a rare but serious complication in pregnancy that places the mother and fetus at high risk for morbidity and mortality. This case illustrates novel pregnancy complications associated with this rare medical condition. CASE PRESENTATION: A 31-year-old G3P0020 at 28 weeks and 1 day was admitted with severe thrombocytopenia and was ultimately diagnosed with TTP. With therapeutic plasma exchange (TPE), maternal status improved. At 28 weeks 6 days, however, non-reassuring fetal testing prompted cesarean delivery with placental abruption noted intraoperatively. Pathology examination confirmed placental abruption and also revealed multiple placental infarcts. CONCLUSION: While medical management of TTP can significantly improve the health of the mother, this case highlights the potential role of TTP in abruption and other placental pathology and thus, the need for close fetal surveillance throughout an affected pregnancy.

High Fetal Fraction on First Trimester Cell-Free DNA Aneuploidy Screening and Adverse Pregnancy Outcomes.

OBJECTIVE: To test the hypothesis that high fetal fraction (FF) on first trimester cell-free deoxyribonucleic acid (cfDNA) aneuploidy screening is associated with adverse perinatal outcomes. STUDY DESIGN: This is a single-institution retrospective cohort study of women who underwent cfDNA screening at <14 weeks' gestation and delivered a singleton infant between July 2016 and June 2018. Women with abnormal results were excluded. Women with high FF (≥95th percentile) were compared with women with normal FF (5th-95th percentiles). Outcomes investigated were preterm birth, small for gestational age, and hypertensive disorders of pregnancy. RESULTS: A total of 2,033 women met inclusion criteria. The mean FF was 10.0%, and FF >16.5% was considered high (n = 102). Women with high FF had a greater chance of delivering a small for gestational age infant

Low Fetal Fraction and Birth Weight in Women with Negative First-Trimester Cell-Free DNA Screening.

OBJECTIVE: To determine the association between low fetal fraction and birth weight among women with a negative cell-free DNA (cfDNA) result for common aneuploidies in the first trimester. STUDY DESIGN: This is a retrospective cohort of women who delivered a singleton between July 2016 and June 2018 at a single institution and had normal cfDNA testing in the first trimester. The primary variable of interest was "low fetal fraction," which was defined as fetal fractions less than 5th percentile among all fetal fractions in the cohort (fetal fraction < 5.34%). The primary outcomes were birth weight ≤ 5th and ≤ 10th percentiles. Multivariable logistic regressions assessed for the association between low fetal fraction and birth weight. RESULTS: A total of 7,478 women delivered a singleton at ≥24 weeks' gestation, of which 2,387 (32%) underwent genetic screening through cfDNA; the majority were in the first trimester (n = 2,052 [86%]). 2,035 met the inclusion criteria. Birth weight ≤ 5th percentile was significantly higher in the low fetal fraction group (6.9 vs. 3.2%; p = 0.04). A low fetal fraction was associated with higher odds of an infant with a low birth weight: adjusted odds ratio (aOR) of 2.32 (95% CI 1.15-4.67) for birth weight ≤ 10th percentile (p = 0.02) and aOR of 3.73 (95% CI 1.40-9.03) for birth weight ≤ 5th percentile (p = 0.004). CONCLUSION: Low fetal fractions of ≤ 5th percentile were associated with an increased risk of birth weights ≤ 5th and ≤ 10th percentiles in women with negative cfDNA screening in the first trimester. Future work is needed to further investigate this relationship and to determine the potential clinical implications, such as third-trimester screening for growth restriction in women with low fetal fractions and negative cfDNA screening results.