COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

Prognosis Walker KF, O'Donoghue K, Grace N, et al. Maternal transmission of SARS-COV-2 to the neonate, and possible routes for such transmission: a systematic review and critical analysis. BJOG. 2020 Oct;127(11):1324-1336. doi: 10.1111/1471-0528.16362. Epub 2020 Jul 22.

BACKGROUND: Early reports of COVID-19 in pregnancy described management by caesarean, strict isolation of the neonate and formula feeding. Is this practice justified?

OBJECTIVE: To estimate the risk of the neonate becoming infected with SARS-CoV-2 by mode of delivery, type of infant feeding and mother-infant interaction.

SEARCH STRATEGY: Two biomedical databases were searched between September 2019 and June 2020.

SELECTION CRITERIA: Case reports or case series of pregnant women with confirmed COVID-19, where neonatal outcomes were reported.

DATA COLLECTION AND ANALYSIS: Data were extracted on mode of delivery, infant infection status, infant feeding and mother-infant interaction. For reported infant infection, a critical analysis was performed to evaluate the likelihood of vertical transmission.

MAIN RESULTS: Forty nine studies included information on mode of delivery and infant infection status for 655 women and 666 neonates. In all, 28/666 (4%) tested positive postnatally. Of babies born vaginally, 8/292 (2.7%) tested positivecompared with 20/374 (5.3%) born by Caesarean. Information on feeding and baby separation were often missing, but of reported breastfed babies 7/148 (4.7%) tested positive compared with 3/56 (5.3%) for reported formula fed ones. Of babies reported as nursed with their mother 4/107 (3.7%) tested positive, compared with 6/46 (13%) for those who were reported as isolated.

CONCLUSIONS: Neonatal COVID-19 infection is uncommon, rarely symptomatic, and the rate of infection is no greater when the baby is born vaginally, breastfed or remains with the mother.

TWEETABLE ABSTRACT: Risk of neonatal infection with COVID-19 by delivery route, infant feeding and mother-baby interaction.

Discipline / Specialty Area Score
Pediatric Neonatology
Infectious Disease
Family Medicine (FM)/General Practice (GP)
Comments from MORE raters

Infectious Disease rater

With little time from the Covid-19 pandemic, systematic reviews have indicated that the virus vertical transmission risk is low. However, studies like these are relevant for obstetricians like me who in this new disease need some evidence to guide their patients about whether or not they can breastfeed and if they are infected with the new coronavirus, whether there is a risk of transmission to their children with serious health consequences. After this well-conducted systematic review in which 28/666 (4%) of the neonates tested positive postnatally, another one was published, (, showing a pooled proportion of 3.2% (95% CI 2.2-4.3%) for vertical transmission, 27/936 had SARS-CoV-2 viral RNA positive nasopharyngeal swab.

Obstetrics rater

The authors made a significant effort to present their information. Amidst the uncertainty associated with this new infection, these exercises make a contribution; although, it is always important to keep in mind the inherent limitations of the studies on which the review is based. It provides some important conclusions to keep in mind when caring for these newborns and neonates.

Obstetrics rater

It's nice to see a study untangle the various case reports around the world and help justify Canadian policies that were in the early days of COVID-19 thought to be best (despite differences with the early Chinese response of high CS rates and discouraging breastfeeding).

Pediatric Neonatology rater

Usual caveats apply in the interpretation of this study, which is primarily based on case reports.