Mother-to-child transmission of SARS-CoV-2 infection in high-income countries: a systematic review and meta-analysis of prospective observational studies

Abstract

Mother-to-child transmission of SARS-CoV-2 has been reported since the onset of the COVID-19 pandemic. We conducted a study to summarize evidence on the risk of mother-to-child transmission in the first 30 days after birth in high-income countries and to evaluate the association between preventive measures and the risk of infection for the neonate. A systematic review and meta-analysis were undertaken following PRISMA guidelines. The National Library of Medicine, Web of Science, and Excerpta Medica databases were screened on February 26, 2022. All prospective observational studies addressing the frequency of infection in infants born to mothers SARS-CoV-2 positive were included. Twenty-six studies were included, reporting data of 2653 mothers with SARS-CoV-2 and 2677 neonates. The proportion meta-analysis pointed out an overall estimate of SARS-CoV-2 infection among infants of 2.3% (95% CI: 1.4–3.2%). Data from studies with (1.4%, 95% CI: 0.8–2) and without (1.3%, 95% CI: 0.0–2.7%) rooming-in provided similar risk of infection. Adopting at least two prevention measures during rooming-in resulted in a rate of mother-to-child infection of 1.0% (95%CI: 0.3–1.7%). The results of this study show a low rate of perinatal infection, support the rooming-in and confirm the effectiveness of preventive measures in reducing the risk of mother-to-child viral transmission.

Maternal and neonatal COVID-19 – the pandemic experience in a tertiary maternity unit in Romania – unicentric, prospective study

“…Similar results were found by other authors [37,63,64]. Even in studies reporting symptomatic neonates born by SARS-CoV-2 positive mothers at birth most of the cases had mild symptoms or complications [3,5,14,19,32,37,38,50,65,66], while severe cases had later neonatal onset and horizontal transmission [3,5,26,67,68], and death were related to prematurity or other co-morbidities in the majority of the few reported cases [14,58,69]. Studies have shown that the severity of the neonatal COVID-19 presentation depends on associated comorbidities, GA and postnatal age, race, gender, general functioning, character of the immune system response, and, recently, on a genetic predisposition [6,70,71].…”

“…Various rates of maternal-neonatal SARS-CoV-2 transmission suggested by neonatal RT-PCR positive test are reported in the literature: 0% by Salvatore et al [59] in 2020, 0,9% by Mullins et al [60] in 2021, 2,2% by Angelidou et al [58] in 2021, 2,9% by Gerhart et al [53] in 2021, 1.9% by Ryan et al [14] in 2022, 1.8-2% by Molloy et al [5] in 2022, 6.5% by Kulkarni et al [56] in 2022, 2-8% by Caballero et al [38] in 2023 or 0% by Lee et al [57] in 2023. Even a recent meta-analysis performed by Morniroli et al [50] reported an odds ratio of maternal-neonatal transmission of SARS-CoV-2 of 2,3% (95% CI 1,4-3,2%), irrespective if the newborn is separated by the mother or cared for in rooming-in. A rate of congenital and intrapartum SARS-CoV-2 virus between 1,8-8% was reported in the systematic review performed by Castellanos et al [54] and 4.5% in the scoping review of Tolu et al in 2021 [61].…”

“…As the pandemic continues, a lot of changes are adding more unanswered questions regarding the impact of SARS-CoV-2 infections on pregnant women and their offspring, the new variants occurring as a result of virus mutations, with different virulence and infectivity (usually with lower virulence and increased contagiousness), changes of the preventive measures and in the maternal and neonatal care, the impact of adult and children vaccination (delayed vaccination of children led to an increased number of infections in children while preventive and control measures and vaccination slowed down the spread and severity of pandemic) being just a few of the new variables that may modify the impact of maternal and neonatal SARS-CoV-2 infections [3,[50][51][52]. Variations in the clinical design of the studies, different patient characteristics, and various effects of virus variants are other important factors for the inconsistent results of the current studies [19].…”