Incidence of SARS-CoV-2 vertical transmission: a meta-analysis

Abstract

The likelihood of newborns acquiring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from infected mothers has raised concerns among families and clinicians worldwide. Published case reports and case series have individually reported wide variability in rate of vertical transmission. We therefore aimed to determine a more precise risk of vertical transmission, either intrauterine or during delivery, by pooling evidence from current studies.We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (CRD42020183500). We searched PubMed, Medline, Embase and China National Knowledge Infrastructure using search terms neonate, pregnancy, COVID-19, 2019-nCoV, SARS-CoV-2 and similar variants until 23 May 2020. Studies reporting mothers who tested positive for SARS-CoV-2 by reverse transcriptase PCR (RT-PCR) and whose newborns were tested by RT-PCR were included. We reviewed 335 full-text articles: 32 studies fulfilled inclusion criteria, 15 overlapping studies were excluded (online supplementary figure 1). An early-onset neonatal infection was defined as newborns with a positive RT-PCR test within the first 2 days of life, and determined by the primary author to not have acquired the infection postnatally. We extracted proportions of newborns with early-onset COVID-19 infection and performed a meta-analysis under a random effects model using the copyright.

Transmission of SARS-CoV-2 to premature twins from an asymptomatic mother

“…This case supports the potential for intrauterine transmission of SARS-CoV-2 as previously reported [1,4]. The incidence of SARS-CoV-2 vertical transmission from reported cases is low; however, this may be due to the difficulty disproving horizontal transmission or underreporting of cases [3]. Moreover, asymptomatic mothers and their babies may not have screening for SARS-CoV-2.…”

“…Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), concerns abound regarding the likelihood of transmission of the virus from infected mothers to the foetus. Published reports have shown cases of newborns acquiring SARS-CoV-2 from infected mothers but the incidence is low [1][2][3]. The difficulty disproving horizontal transmission, under-reporting of cases and not routinely screening all mothers admitted for delivery and their newborn babies could contribute to the reported low incidence of vertical transmission.…”

A case report of neonatal coronavirus disease-19 infection in South India

“…A recent meta-analysis on the incidence of SARS-CoV-2 vertical transmission by Goh et al [9] included 17 studies. Four hundred and two COVID-19-positive mothers delivered 405 newborns, of which 330 newborns underwent early RT-PCR tests.…”

Generation COVID‐19 – Should the foetus be worried?

“…Pregnant women and their foetuses have been amongst those with the poorest outcomes in previous epidemics such as Ebola, Zika, SARS and MERS 3 . Initial reports suggest that perinatal infection with SARS‐CoV‐2 is reassuringly rare 4 . However, the complex socio‐economic, domestic and broader maternal lifestyle factors, which can influence a child's lifelong well‐being, have been modulated during the experience of this pandemic (Figure 1).…”