COVID-19: the possibility, ways, mechanisms, and interruptions of mother-to-child transmission

Preserved prenatal lung growth assessed by fetal MRI in the omicron-dominated phase of the SARS-CoV-2 pandemic

OBJECTIVES

With SARS-CoV-2 evolving, disease severity and presentation have changed due to changes in mechanisms of entry and effector site as well as due to effects of vaccination- and/or infection-acquired immunity. We re-assessed fetal lung pathology in pregnancies with uncomplicated SARS-CoV-2 infections during the late, omicron-dominated pandemic phase to inform disease understanding and pregnancy consultation.

METHODS

In this case-control study, fetal lung volumes were assessed by fetal MRI in 24 pregnancies affected by mild maternal SARS-CoV-2 infection during the omicron-dominated pandemic phase with prevailing immunity through vaccination and/or prior SARS-CoV-2 infection.

RESULTS

Fetal lung volumes (normalized to estimated fetal weight) in 24 pregnancies (GA 33.3 ± 3.8, 12 female fetuses) following mild, uncomplicated SARS-CoV-2 infection did not differ significantly from both, published reference values (96.3% ± 22.5% of 50th percentile reference values, p = 0.43), or fetal lung volumes of a site-specific, non-COVID control group (n = 15, 94.2% ± 18.5%, p = 0.76). Placental assessment revealed no group differences in thrombotic changes or placental heterogeneity (p > 0.05, respectively), and fetal lung volume did not correlate with placental heterogeneity when adjusting for gestational age at scan (p > 0.05).

CONCLUSION

Assessment of fetal lung volume by MRI revealed unaffected lung growth in pregnancies affected by uncomplicated SARS-CoV-2 infection in the omicron-dominated pandemic phase in the presence of prevailing hybrid immunity. This finding contrasts sharply with the observed reduction in fetal lung volume following maternal alpha-variant infection in the pre-vaccination era and might reflect tropism- as well as immunity-related effects.

KEY POINTS

Question: Is fetal lung development affected by mild maternal SARS-CoV-2 infection during the omicron-dominated phase of the pandemic?

FINDINGS

Fetal lung volume in 24 affected pregnancies did not differ significantly from published reference values or fetal lung volumes in 15 site-specific, non-COVID-affected control pregnancies.

CLINICAL RELEVANCE

Preserved fetal lung volume following mild maternal SARS-CoV-2 infection during the omicron-dominated phase contrasts with previous findings of reduced volume in unvaccinated pregnancies during the alpha-dominated pandemic phase. These observations might reflect tropism- as well as immunity-related effects.

Management of neonates with maternal prenatal coronavirus infection and influencing factors

The coronavirus disease 2019 (COVID-19) in pregnancy causes adverse outcomes for both the mother and the fetus. Neonates are at risk of vertical transmission and in-utero infection. Additionally, intensive care unit (ICU) admission and impairment in the organ systems of the mother are associated with neonatal outcomes, including impaired intrauterine growth, prematurity, and neonatal ICU admission. The management of neonates born from infected mothers has changed over the progress of the pandemic. At the beginning of the pandemic, cesarean section, immediate separation of mother-infant dyads, isolation of neonates, and avoiding of skin-to-skin contact, breast milk, and breastfeeding were the main practices to reduce vertical and horizontal transmission risk in the era of insufficient knowledge. The effects of antenatal steroids and delayed cord clamping on COVID-19 were also not known. As the pandemic progressed, data showed that prenatal, delivery room, and postnatal care of neonates can be performed as pre-pandemic practices. Variants and vaccines that affect clinical course and outcomes have emerged during the pandemic. The severity of the disease and the timing of infection in pregnancy also influence maternal and neonatal outcomes. The knowledge and lessons from COVID-19 will be helpful for the next pandemic if it happens. IMPACT: Prenatal infection with COVID-19 is associated with adverse maternal and neonatal outcomes. Our review includes the management of neonates with prenatal COVID-19 infection exposure, maternal-fetal, delivery room, and postnatal care of neonates, clinical features, treatment of neonates, and influencing factors such as variants, vaccination, severity of maternal disease, and timing of infection during pregnancy. There is a growing body of data and evidence about the COVID-19 pandemic. The knowledge and lessons from the pandemic will be helpful for the next pandemic if it happens.

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.

Vaccination during pregnancy: A golden opportunity to embrace

Immunization strategies are part of routine pregnancy care to prevent infectious diseases in the mother, the fetus, and the newborn. Maternal immunization recommendations followed the recognition of the consequences of infectious diseases in pregnancy, including vertical transmission and perinatal consequences. The recent COVID-19 pandemic highlighted the issue of vaccination among pregnant individuals. Recommendations vary globally; however, Tdap, influenza, and, recently, COVID-19 vaccines are routinely recommended during pregnancy. There are several new maternal immunization products in the pipeline, including those directed against malaria, cytomegalovirus, Group B Streptococcus, herpes simplex virus, and respiratory syncytial virus. Important challenges must be addressed in all countries to guarantee that pregnant individuals and their babies receive the best care possible, including uptake of recommended immunizations by their entire target population groups. These challenges include disseminating appropriate data for vaccine recommendations and many others, such as ensuring stakeholder endorsement, achieving in-country distribution and administration, adequate vaccine supply, and a well-organized healthcare system, ideally offering the immunization free of charge. More recently, the hesitancy of pregnant women to receive immunizations highlights the relevance of cultural aspects and other contextual factors affecting vaccine uptake among pregnant individuals.

Early Postnatal Infection of Neonates Born to Mothers Infected by SARS-CoV-2 Omicron Variant

OBJECTIVES

To evaluate the rate of postnatal infection during the first month of life in neonates born to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive mothers during the predominant circulation of the omicron (B.1.1.529) variant.

METHODS

This prospective, 10-center study enrolled mothers infected by SARS-CoV-2 at delivery and their infants, if both were eligible for rooming-in, between December 2021 and March 2022. Neonates were screened for SARS-CoV-2 RNA at 1 day of life (DOL), 2 to 3 DOL, before discharge, and twice after hospital discharge. Mother-infant dyads were managed under a standardized protocol to minimize the risk of viral transmission. Sequencing data in the study area were obtained from the Italian Coronavirus Disease 2019 Genomic platform. Neonates were included in the final analysis if they were born when the omicron variant represented >90% of isolates.

RESULTS

Eighty-two percent (302/366) of mothers had an asymptomatic SARS-CoV-2 infection. Among 368 neonates, 1 was considered infected in utero (0.3%), whereas the postnatal infection rate during virtually exclusive circulation of the omicron variant was 12.1%. Among neonates infected after birth, 48.6% became positive during the follow-up period. Most positive cases at follow-up were detected concurrently with the peak of coronavirus disease 2019 cases in Italy. Ninety-seven percent of the infected neonates were asymptomatic.

CONCLUSIONS

The risk of early postnatal infection by the SARS-CoV-2 omicron variant is higher than that reported for previously circulating variants. However, protected rooming-in practice should still be encouraged given the paucity of symptoms in infected neonates.

Transmission of SARS-CoV-2 from mother to fetus or neonate: What to know and what to do?

SARS-CoV-2 can be vertically transmitted from the mother to the fetus and the neonate. This transmission route is rare compared to the environmental or horizontal spread and therefore, the risk can be deemed inconsequential by some medical providers. However, severe, although just as rare, feto-neonatal consequences are possible: fetal demise, severe/critical neonatal COVID-19 and multi-inflammatory syndrome (MIS-N) have been described. Therefore, it is important for the clinicians to know the mechanism of vertical transmission, how to recognize this, and how to deal with neonatal COVID-19 and MIS-N. Our knowledge about this field has significantly increased in the last three years. This is a summary of the pathophysiology, diagnostics, and therapeutics of vertical SARS-CoV-2 transmission that clinicians apply in their clinical practice.