Maternal and Perinatal Outcomes Associated With Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection During Pregnancy, Florida, 2020-2021: A Retrospective Cohort Study

Perinatal outcomes after admission with COVID-19 in pregnancy: a UK national cohort study

There are few population-based studies of sufficient size and follow-up duration to have reliably assessed perinatal outcomes for pregnant women hospitalised with SARS-CoV-2 infection. The United Kingdom Obstetric Surveillance System (UKOSS) covers all 194 consultant-led UK maternity units and included all pregnant women admitted to hospital with an ongoing SARS-CoV-2 infection. Here we show that in this large national cohort comprising two years' active surveillance over four SARS-CoV-2 variant periods and with near complete follow-up of pregnancy outcomes for 16,627 included women, severe perinatal outcomes were more common in women with moderate to severe COVID-19, during the delta dominant period and among unvaccinated women. We provide strong evidence to recommend continuous surveillance of pregnancy outcomes in future pandemics and to continue to recommend SARS-CoV-2 vaccination in pregnancy to protect both mothers and babies.

SARS-CoV-2 infection by trimester of pregnancy and adverse perinatal outcomes: a Mexican retrospective cohort study

OBJECTIVE

Conflicting evidence for the association between COVID-19 and adverse perinatal outcomes exists. This study examined the associations between maternal COVID-19 during pregnancy and adverse perinatal outcomes including preterm birth (PTB), low birth weight (LBW), small-for-gestational age (SGA), large-for-gestational age (LGA) and fetal death; as well as whether the associations differ by trimester of infection.

DESIGN AND SETTING

The study used a retrospective Mexican birth cohort from the Instituto Mexicano del Seguro Social (IMSS), Mexico, between January 2020 and November 2021.

PARTICIPANTS

We used the social security administrative dataset from IMSS that had COVID-19 information and linked it with the IMSS routine hospitalisation dataset, to identify deliveries in the study period with a test for SARS-CoV-2 during pregnancy.

OUTCOME MEASURES

PTB, LBW, SGA, LGA and fetal death. We used targeted maximum likelihood estimators, to quantify associations (risk ratio, RR) and CIs. We fit models for the overall COVID-19 sample, and separately for those with mild or severe disease, and by trimester of infection. Additionally, we investigated potential bias induced by missing non-tested pregnancies.

RESULTS

The overall sample comprised 17 340 singleton pregnancies, of which 30% tested positive. We found that those with mild COVID-19 had an RR of 0.89 (95% CI 0.80 to 0.99) for PTB and those with severe COVID-19 had an RR of 1.53 (95% CI 1.07 to 2.19) for LGA. COVID-19 in the first trimester was associated with fetal death, RR=2.36 (95% CI 1.04, 5.36). Results also demonstrate that missing non-tested pregnancies might induce bias in the associations.

CONCLUSIONS

In the overall sample, there was no evidence of an association between COVID-19 and adverse perinatal outcomes. However, the findings suggest that severe COVID-19 may increase the risk of some perinatal outcomes, with the first trimester potentially being a high-risk period.

The impact of gestational weeks of Coronavirus disease 2019 (COVID-19) infection on perinatal outcomes

BACKGROUND

To evaluate the relationship between coronavirus disease 2019 (COVID-19) infection at different time points during pregnancy and perinatal outcomes.

METHODS

This retrospective study included 611 women who hospitalized for delivery between December 7 and April 30, 2023. Based on the different pregnancy weeks infected with COVID-19, the participants were divided into four groups: Group 1 (14-27+6 weeks gestation), Group 2 (28-36+6 weeks gestation), Group 3 (37-39+6 weeks gestation), and Group 4 (≥ 40 weeks gestation). Data including maternal demographic characteristics, clinical profiles, and perinatal outcomes were analyzed.

RESULTS

There were no significant differences in maternal demographic characteristics among the four groups (P > 0.05). Compared to Groups 3 and 4, a higher rate of fever was noted in Groups 1 and 2 (P < 0.05). The frequency of preeclampsia and gestational diabetes mellitus showed a decreasing trend as pregnancy progressing (P < 0.05). Preterm delivery and neonatal intensive care unit admission were more frequently observed in Groups 1 and 2 than in Groups 3 and 4 (P < 0.05). Multivariate logistic regression analysis demonstrated that the timing of gestation in which COVID-19 was infected was not associated with preterm delivery and neonatal intensive care unit admission (P > 0.05), whereas gestational age at COVID-19 infection was negatively associated with the occurrence of preeclampsia and gestational diabetes mellitus (P < 0.05).

CONCLUSIONS

Gestational age at COVID-19 infection is a simple parameter that predicts adverse perinatal outcomes to aid clinicians in determining to provide early enhanced prenatal care and increased monitoring to reduce maternal complications.

Factors associated with hospitalizations and deaths of pregnant women from Paraná due to COVID-19: a cross-sectional study

OBJECTIVE

To analyze the factors associated with hospitalization in the ward and intensive care unit (ICU), and with death from COVID-19 in pregnant women with confirmed cases.

METHODS

Observational, cross-sectional study, carried out with data from pregnant women with a confirmed case of COVID-19 from the Influenza Epidemiological Surveillance Information System and the Paraná's state COVID-19 notification system. The association between the independent and dependent variables (hospitalization in the ward and ICU, and death) was investigated using the Poisson regression model with robust variance.

RESULTS

4,719 pregnant women comprised the study population. 9.6 and 5.1% were hospitalized in wards and ICU, respectively. 1.9% died. There was an association between advanced maternal age and hospitalization in wards (PR=1.36; 95%CI 1.10-1.62) and ICU (PR=2.25; 95%CI 1.78-2.71), and death (PR=3.22; 95%CI 2.30-4.15). An association was found between the third trimester and hospitalization in wards (PR=5.06; 95%CI 2.82-7.30) and ICU (PR=6.03; 95%CI 3.67-8.39) and death (PR=13.56; 95%CI 2.90-24.23). The second trimester was associated with ICU admission (PR=2.67; 95%CI 1.36-3.99). Pregnant women with cardiovascular disease had a higher frequency of hospitalization in wards (PR=2.24; 95%CI 1.43-3.05) and ICU (PR=2.66; 95%CI 1.46-3.87). Obesity was associated with ICU admission (PR=3.79; 95%CI 2.71-4.86) and death (PR=5.62; 95%CI 2.41-8.83).

CONCLUSIONS

Advanced maternal age, the end of the gestational period and comorbidities were associated with severe COVID-19.

Neonatal outcomes of maternal prenatal coronavirus infection

The coronavirus disease 2019 (COVID-19) pandemic has led to significant changes in life and healthcare all over the world. Pregnant women and their newborns require extra attention due to the increased risk of adverse outcomes. Adverse pregnancy outcomes include intensive care unit (ICU) admission, pulmonary, cardiac, and renal impairment leading to mortality. Immaturity and variations of the neonatal immune system may be advantageous in responding to the virus. Neonates are at risk of vertical transmission and in-utero infection. Impaired intrauterine growth, prematurity, vertical transmission, and neonatal ICU admission are the most concerning issues. Data on maternal and neonatal outcomes should be interpreted cautiously due to study designs, patient characteristics, clinical variables, the effects of variants, and vaccination beyond the pandemic. Cesarean section, immediate separation of mother-infant dyads, isolation of neonates, and avoidance of breast milk were performed to reduce transmission risk at the beginning of the pandemic in the era of insufficient knowledge. Vertical transmission was found to be low with favorable short-term outcomes. Serious fetal and neonatal outcomes are not expected, according to growing evidence. Long-term effects may be associated with fetal programming. Knowledge and lessons from COVID-19 will be helpful for the next pandemic if it occurs. IMPACT: Prenatal infection with SARS-CoV-2 is associated with adverse maternal and neonatal outcomes. Our review includes the effects of COVID-19 on the fetus and neonates, transmission routes, placental effects, fetal and neonatal outcomes, and long-term effects on neonates. There is a growing body of data and evidence about the COVID-19 pandemic. Knowledge and lessons from the pandemic will be helpful for the next pandemic if it happens.

Mild/asymptomatic COVID-19 in unvaccinated pregnant mothers impairs neonatal immune responses

Maternal SARS-CoV-2 infection triggers placental inflammation and alters cord blood immune cell composition. However, most studies focus on outcomes of severe maternal infection. Therefore, we analyzed cord blood and chorionic villi from newborns of unvaccinated mothers who experienced mild/asymptomatic SARS-CoV-2 infection during pregnancy. We investigated immune cell rewiring using flow cytometry, single-cell RNA sequencing, and functional readouts using ex vivo stimulation with TLR agonists and pathogens. Maternal infection was associated with increased frequency of memory T and B cells and nonclassical monocytes in cord blood. Ex vivo T and B cell responses to stimulation were attenuated, suggesting a tolerogenic state. Maladaptive responses were also observed in cord blood monocytes, where antiviral responses were dampened but responses to bacterial TLRs were increased. Maternal infection was also associated with expansion and activation of placental Hofbauer cells, secreting elevated levels of myeloid cell-recruiting chemokines. Moreover, we reported increased activation of maternally derived monocytes/macrophages in the fetal placenta that were transcriptionally primed for antiviral responses. Our data indicate that even in the absence of vertical transmission or symptoms in the neonate, mild/asymptomatic maternal COVID-19 altered the transcriptional and functional state in fetal immune cells in circulation and in the placenta.

Mild/Asymptomatic Maternal SARS-CoV-2 Infection Leads to Immune Paralysis in Fetal Circulation and Immune Dysregulation in Fetal-Placental Tissues

Few studies have addressed the impact of maternal mild/asymptomatic SARS-CoV-2 infection on the developing neonatal immune system. In this study, we analyzed umbilical cord blood and placental chorionic villi from newborns of unvaccinated mothers with mild/asymptomatic SARSCoV-2 infection during pregnancy using flow cytometry, single-cell transcriptomics, and functional assays. Despite the lack of vertical transmission, levels of inflammatory mediators were altered in cord blood. Maternal infection was also associated with increased memory T, B cells, and non-classical monocytes as well as increased activation. However, ex vivo responses to stimulation were attenuated. Finally, within the placental villi, we report an expansion of fetal Hofbauer cells and infiltrating maternal macrophages and rewiring towards a heightened inflammatory state. In contrast to cord blood monocytes, placental myeloid cells were primed for heightened antiviral responses. Taken together, this study highlights dysregulated fetal immune cell responses in response to mild maternal SARS-CoV-2 infection during pregnancy.

Risk Factors of Severe COVID-19: A Review of Host, Viral and Environmental Factors

The clinical course and outcome of COVID-19 are highly variable, ranging from asymptomatic infections to severe disease and death. Understanding the risk factors of severe COVID-19 is relevant both in the clinical setting and at the epidemiological level. Here, we provide an overview of host, viral and environmental factors that have been shown or (in some cases) hypothesized to be associated with severe clinical outcomes. The factors considered in detail include the age and frailty, genetic polymorphisms, biological sex (and pregnancy), co- and superinfections, non-communicable comorbidities, immunological history, microbiota, and lifestyle of the patient; viral genetic variation and infecting dose; socioeconomic factors; and air pollution. For each category, we compile (sometimes conflicting) evidence for the association of the factor with COVID-19 outcomes (including the strength of the effect) and outline possible action mechanisms. We also discuss the complex interactions between the various risk factors.

The impact of maternal SARS-CoV-2 infection and COVID-19 vaccination on maternal-fetal outcomes

The rapidly evolving COVID-19 pandemic has resulted in an upsurge of scientific productivity to help address the global health crisis. One area of active research is the impact of COVID-19 on pregnancy. Here, we provide an epidemiological overview about what is known about the effects of maternal SARS-CoV-2 infection and COVID-19 vaccination on maternal-fetal outcomes, and identify gaps in knowledge. Pregnant people are at increased risk for severe COVID-19, and maternal SARS-CoV-2 infection increases the risk of negative maternal-fetal outcomes. Despite this elevated risk, there have been high rates of vaccine hesitancy, heightened by the initial lack of safety and efficacy data for COVID-19 vaccination in pregnancy. In response, retrospective cohort studies were performed to examine the impact of COVID-19 vaccination during pregnancy. Here, we report the vaccine's efficacy during pregnancy and its impact on maternal-fetal outcomes, as well as an overview of initial studies on booster shots in pregnancy. We found that pregnant people are at risk for more severe COVID-19 outcomes, maternal SARS-CoV-2 infection is associated with worse birth outcomes, COVID-19 vaccine hesitancy remains prevalent in the pregnant population, and COVID-19 vaccination and boosters promote better maternal-fetal outcomes. The results should help reduce vaccine hesitancy by alleviating concerns about the safety and efficacy of administering the COVID-19 vaccine during pregnancy. Overall, this review provides an introduction to COVID-19 during pregnancy. It is expected to help consolidate current knowledge, accelerate research of COVID-19 during pregnancy and inform clinical, policy, and research decisions regarding COVID-19 vaccination in pregnant people.

Vaccines, Variants, and Vigilance: Strengthening the Coronavirus Disease 2019 (COVID-19) Public Health Response Through Partnerships and Collaborations

The US Centers for Disease Control and Prevention (CDC); state, tribal, local, and territorial health departments; other US government departments and agencies; the private sector; and international partners have engaged in a real-time public health response to the coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Vaccination, variants, and vigilance were themes that arose in the second year of pandemic response in the United States. The findings included in this supplement emerged from these themes and represent some of the many collaborative efforts to improve public health knowledge and action to reduce transmission, infection, and disease severity.