Maternal respiratory SARS-CoV-2 infection in pregnancy is associated with a robust inflammatory response at the maternal-fetal interface.

BACKGROUND: Pregnant women are at increased risk for severe outcomes from coronavirus disease 2019 (COVID-19), but the pathophysiology underlying this increased morbidity and its potential effect on the developing fetus is not well understood. METHODS: We assessed placental histology, ACE2 expression, and viral and immune dynamics at the term placenta in pregnant women with and without respiratory severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. FINDINGS: The majority (13 of 15) of placentas analyzed had no detectable viral RNA. ACE2 was detected by immunohistochemistry in syncytiotrophoblast cells of the normal placenta during early pregnancy but was rarely seen in healthy placentas at full term, suggesting that low ACE2 expression may protect the term placenta from viral infection. Using immortalized cell lines and primary isolated placental cells, we found that cytotrophoblasts, the trophoblast stem cells and precursors to syncytiotrophoblasts, rather than syncytiotrophoblasts or Hofbauer cells, are most vulnerable to SARS-CoV-2 infection in vitro. To better understand potential immune mechanisms shielding placental cells from infection in vivo, we performed bulk and single-cell transcriptomics analyses and found that the maternal-fetal interface of SARS-CoV-2-infected women exhibited robust immune responses, including increased activation of natural killer (NK) and T cells, increased expression of interferon-related genes, as well as markers associated with pregnancy complications such as preeclampsia. CONCLUSIONS: SARS-CoV-2 infection in late pregnancy is associated with immune activation at the maternal-fetal interface even in the absence of detectable local viral invasion. FUNDING: NIH (T32GM007205, F30HD093350, K23MH118999, R01AI157488, U01DA040588) and Fast Grant funding support from Emergent Ventures at the Mercatus Center.

Coronavirus disease 2019 pregnancy outcomes in a racially and ethnically diverse population.

Background: Older age and medical comorbidities are identified risk factors for developing severe coronavirus disease 2019. However, there are limited data on risk stratification, clinical and laboratory course, and optimal management of coronavirus disease 2019 in pregnancy. Objective: Our study aimed to describe the clinical course of coronavirus disease 2019, effect of comorbidities on disease severity, laboratory trends, and pregnancy outcomes of symptomatic and asymptomatic severe acute respiratory syndrome coronavirus 2-positive pregnant women. Study Design: This is a case series of pregnant and postpartum women who received positive test results for severe acute respiratory syndrome coronavirus 2 between March 3, 2020, and May 11, 2020, within 3 hospitals of the Yale New Haven Health delivery network. Charts were reviewed for basic sociodemographic and prepregnancy characteristics, coronavirus disease 2019 course, laboratory values, and pregnancy outcomes. Results: Of the 1567 tested pregnant and postpartum women between March 3, 2020, and May 11, 2020, 9% (n=141) had a positive severe acute respiratory syndrome coronavirus 2 result. Hispanic women were overrepresented in the severe acute respiratory syndrome coronavirus 2-positive group (n=61; 43.8%). In addition, Hispanic ethnicity was associated with a higher rate of moderate and severe diseases than non-Hispanic (18% [11/61] vs 3.8% [3/78], respectively; odds ratio, 5.5; 95% confidence interval, 1.46-20.7; P=.01). Of note, 44 women (31.2%) were asymptomatic, 37 of whom (26.2%) were diagnosed on universal screening upon admission for delivery. Moreover, 59% (n=83) were diagnosed before delivery, 36% (n=51) upon presentation for childbirth, and 5% (n=7) after delivery. Severe disease was diagnosed in 6 cases (4.3%), and there was 1 maternal death. Obese women were more likely to develop moderate and severe diseases than nonobese women (16.4% [9/55] vs 3.8% [3/79]; odds ratio, 4.96; 95% confidence interval, 1.28-19.25; P=.02). Hypertensive disorders of pregnancy were diagnosed in 22.3% of women (17/77) who delivered after 20 weeks' gestation. Higher levels of C-reactive protein during antepartum coronavirus disease 2019-related admission were more common in women with worse clinical course; however, this association did not reach statistical significance. Conclusion: Coronavirus disease 2019 in pregnancy may result in severe disease and death. Hispanic women were more likely to receive a positive test result for severe acute respiratory syndrome 2 than other ethnic groups. Obesity and Hispanic ethnicity represent risk factors for moderate and severe diseases.

Consolidation of obstetric services in a public health emergency.

Though much of routine healthcare pauses in a public health emergency, childbirth continues uninterrupted. Crises like COVID-19 put incredible strains on healthcare systems and require strategic planning, flexible adaptability, clear communication, and judicious resource allocation. Experiences from obstetric units affected by COVID-19 highlight the importance of developing new teams and workflows to ensure patient and healthcare worker safety. Additionally, adapting a strategy that combines units and staff from different areas and hospitals can allow for synergistic opportunities to provision care appropriately to manage a structure and workforce at maximum capacity.

SARS-CoV-2 infection of the placenta.

BACKGROUNDThe effects of the novel coronavirus disease 2019 (COVID-19) in pregnancy remain relatively unknown. We present a case of second trimester pregnancy with symptomatic COVID-19 complicated by severe preeclampsia and placental abruption.METHODSWe analyzed the placenta for the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through molecular and immunohistochemical assays and by and electron microscopy and measured the maternal antibody response in the blood to this infection.RESULTSSARS-CoV-2 localized predominantly to syncytiotrophoblast cells at the materno-fetal interface of the placenta. Histological examination of the placenta revealed a dense macrophage infiltrate, but no evidence for the vasculopathy typically associated with preeclampsia.CONCLUSIONThis case demonstrates SARS-CoV-2 invasion of the placenta, highlighting the potential for severe morbidity among pregnant women with COVID-19.FUNDINGBeatrice Kleinberg Neuwirth Fund and Fast Grant Emergent Ventures funding from the Mercatus Center at George Mason University. The funding bodies did not have roles in the design of the study or data collection, analysis, and interpretation and played no role in writing the manuscript.