Is it possible to transmit COVID-19 in the womb?

Intrauterine transmission of SARS-CoV-2 is rare but possible, with early postnatal transmission occurring more often, a study has found. Infected newborns are mostly asymptomatic or have mild symptoms that improve during follow-up.

“We did not find any maternal characteristics predisposing infants to neonatal infection,” the authors said. “All infected newborn mothers had acute infection at delivery.”

This prospective, observational, and multicentric study involved 13 Spanish hospitals that were part of the Gestational and Neonatal-COVID cohort. Pregnant women with microbiologically confirmed SARS-CoV-2 infection during any trimester of pregnancy or delivery and their newborns from March to November 2020 were included.

The authors obtained demographic, clinical, and microbiological data. They also analysed viral loads in different maternal and newborn biological samples (ie, placenta, breast milk, and maternal blood; urine, meconium, and newborn blood).

A total of 177 newborns exposed to SARS-CoV-2 were included and tested by reverse transcriptase-polymerase chain reaction using nasopharyngeal swabs within the first 24–48 hours of life and at 14 days of life. Of these, 5.1 percent were deemed to have SARS-CoV-2 infection in the neonatal period, with 1.7 percent considered intrauterine and 3.4 percent intrapartum or early postnatal transmission cases.

No differences were seen in the demographic and clinical characteristics of the pregnant women and their newborns’ susceptibility to infections in their perinatal history or background.

“Although there was no presence of SARS-CoV2 in cord blood or breast milk samples, SARS-CoV-2 viral load was detected in urine and meconium samples from infected newborns,” the authors said.