Effects of the Omicron variant on perinatal outcomes in full-term neonates

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.

Perinatal outcomes of pregnancies affected by COVID-19 in Singapore: A cohort study

Pregnant women and infants were not spared from the coronavirus disease 2019 (COVID-19) after it was first identified in December 2019.1,2 In the beginning of the pandemic, a lack of data on transmission risks and outcomes of pregnancies affected by SARS-CoV-2, impacted perinatal clinical decision-making.1,3 We report the perinatal outcomes of pregnancies affected by COVID-19 in Singapore, covering the period from initial virus identification to the emergence of the Omicron variant in late 2021. We investigated the impact of COVID-19 vaccination and the Omicron variant on the perinatal outcomes of infected pregnant women and their newborns.

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.

Effects of intrauterine exposure to SARS-CoV-2 on infants' development: a rapid review and meta-analysis

Potential medium- and long-term neurodevelopmental sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy have not been ruled out. We aimed to systematically review and summarize the evidence regarding the effects of intrauterine exposure to SARS-CoV-2 on infant development and behavior. Scopus, PubMed, Web of Science, CINAHL, and PsycNet databases were searched for studies published up to February 6, 2023, investigating the effects of gestational SARS-CoV-2 on infant development and behavior. We performed narrative synthesis according to updated protocols. Studies using comparison groups and with the Ages and Stages Questionnaires-Third Edition (ASQ-3) scores available were included in a meta-analysis performed according to Cochrane protocols. We used the Newcastle-Ottawa Quality Assessment Scale to analyze the risk of bias. Heterogeneity was calculated using the I² statistic. The search identified 2,782 studies. After removing duplicates and applying the eligibility criteria, we performed a narrative synthesis of 10 included studies and a meta-analysis of three. There was no evidence of higher developmental delay rates in infants exposed to SARS-CoV-2 during pregnancy compared to non-exposed infants. However, the exposed infants scored lower than either the non-exposed children or pre-pandemic cohorts in some domains. Pooled results from the random-effects model indicated that SARS-CoV-2-exposed infants had lower scores on fine motor (mean difference [MD] = -4.70, 95% confidence interval [CI]: -8.76; -0.63), and problem-solving (MD = -3.05, 95% CI: -5.88; -0.22) domains than non-exposed infants (heterogeneity: I² = 69% and 88%, respectively). There was no difference between the exposed and non-exposed infants in the communication, gross motor, and personal-social ASQ-3 domains.  Conclusion: We did not find evidence confirming the association between SARS-CoV-2 gestational exposure and neurodevelopmental delays. However, the meta-analysis indicated that gestational exposure negatively affected fine motor and problem-solving skills. Robust evidence on this topic is still incipient, and the available studies present methodological inconsistencies that limit the drawing of clear-cut conclusions.   PROSPERO registration: #CRD42022308002; March 14, 2022. What is Known: • COVID-19 is associated with adverse pregnancy outcomes potentially linked to neurodevelopmental delays. • SARS-CoV-2 vertical transmission is rare; however, infections during pregnancy can be deleterious to the fetus, possibly mediated by maternal immune activation and other inflammatory mechanisms. What is New: • No evidence of increased developmental delay rates among SARS-CoV-2 gestational-exposed infants was found. However, a meta-analysis of three studies showed lower scores in fine motor and personal social ASQ-3 domains among exposed infants. • SARS-CoV-2 gestational exposure and the pandemic can affect child development via many mechanisms. Potential neurodevelopmental sequelae of SARS-CoV-2 exposure during gestation have not been ruled out.