Environmental exposure to SARS-CoV-2 is responsible for most of the infections registered in newborns but about 30% of babies could have been born with the infection transmitted by the mother during pregnancy or delivery, according to a study published in Nature Communications and based on 176 cases reported as of August 30, 2020.
To conduct the study, the researchers, led by Daniele De Luca, from Paris Saclay University Hospitals (Clamart, France), conducted a meta-analysis of published cases of SARS-CoV-2 infection in newborns (within the first 30 days life), confirmed by at least one positive PCR test and / or the detection of specific antibodies in the blood.
The authors found that in seven out of ten cases, contagion was the result of postpartum environmental exposure and that about 30% “was probably the result of vertical transmission (transmission of the virus from mother to baby)”, since be it intrapartum or congenitally .
In addition, in about 9% of the 176 cases, it was confirmed that the infection was due to vertical transmission during pregnancy or delivery.
In the graph we can see two different areas. Areas in blue represent confirmed or presumed environmentally acquired (i.e. postpartum) infections, while areas in brown represent confirmed or presumed vertically transmitted infections (either intrapartum or congenitally).
55% of the babies (97) in the analysis developed COVID-19, with clinical symptoms similar to those reported in older patients, such as respiratory problems (52% of cases), fever (44%), and gastrointestinal (36%) ), and neurological (18%), according to the authors.
When examining infections that occurred at least 72 hours after birth, the researchers found that infants in the sample who remained in a crib next to their mother in the hospital (housed in a room) appeared to have a higher incidence of SARS-CoV-2 infections.
The study authors argue that if the mother and child live together, hygiene measures and adequate protective equipment should be available to reduce the risk of transmission through exposure to the environment.
They also note that breastfeeding was not associated with SARS-CoV-2 infection and suggest that viral transmission through milk is rare, if at all, although more studies will be needed to confirm this.
In Babies and more | A systematic review concludes that mother-to-baby transmission of COVID-19 during pregnancy is rare