Newborns Not at Increased Perinatal COVID-19 Risk

Perinatal transmission of coronavirus 2019 (COVID-19) is very unlikely in circumstances where hygienic protocol and safe breastfeeding is correctly practiced, according to new findings from New York-based investigators.

In an observational cohort assessment of neonates born at 1 of 3 New York Presbyterian Hospitals in New York City from March 22 — May 17, investigators discovered that SARS-CoV-2 positivity in new mothers was not associated with neonatal infant infection.

The team, led by Christine M. Salvatore, MD, of Weill Cornell Medicine at New York Presbyterian-Komansky Children’s Hospital, found results which differ from rtPCR testing-based results showing that perinatal transmission of SARS-CoV-2 to neonates from infected mothers or family members is highly susceptible. None of their observed neonates developed asymptomatic infection, in fact.

“Because about half of the mothers were symptomatic shortly before or during delivery, acquisition of protective maternal antibodies in all infants is unlikely,” they noted. “Moreover, our data show no difference in neonatal outcome on the basis of whether mothers were symptomatic or not.”

Salvatore and colleagues conducted their observational cohort of neonate mothers who tested SARS-CoV-2 positive via nasopharyngeal swab sample at the time of their delivery near the peak of COVID-19 spread in the city.

Nenoates were tested for SARS-CoV-2 via PCR, cobas, and other approved methods and assays, from their first 12-24 hours, then again after 5-7 days, and again at 14 days. Based on what was then known about viral shedding and antibody response, investigators believed mothers were unlikely to remain infectious at that time—and if neonates were still testing negatively at that point, their likelihood of continued transmission risk was unlikely.

Mothers were advised to practice skin-to-skin care and breastfeed in the delivery room, but to also wear a surgical mask when near their neonate and practice proper handwashing prior to skin-to-skin contact, breastfeeding, and routine care.

Unless medically required, neonates were kept in a closed isolette in the same room as their mothers. Clinicians recorded patient demographics, neonatal and maternal clinical presentation, infection control practices conducted at both the hospitals and homes, and conducted clinical telemedicine evaluations at 1 month.

Of the 1481 recorded deliveries, 116 (8%) mothers tested positive for SARS-CoV-2; among them, 120 neonates were identified. At 24 hours of life, none were positive for SARS-CoV-2.

Another 82 (68%) of the neonates completed follow-up at day 5-7. Of them, 68 (83%) roomed in with their mothers. All observed mothers were allowed to breastfeed; 64 (78%) were still breastfeeding at that time. Repeat PCR at that time confirmed all 82 neonates were still negative for SARS-CoV-2.

Another 72 neonates were again tested at 14 days of life; again, none were positive. At no point did investigators observe neonate symptoms of COVID-19.

To the knowledge of investigators, this was the largest US cohort of neonates born to SARS-CoV-2-positive mothers who were subsequently followed for serial testing and clinical assessment for up to 1 month.

“In our case series, no infant had SARS-CoV-2 virus detected by a nasopharyngeal swab in the immediate postnatal period, nor at 5—7 or 14 days of life,” they wrote. “This finding supports the previous reports of a low risk of perinatal transmission with strict infection control practices.”

In an interview with Contagion®, Mary Jane Minkin, MD, OB/GYN, clinical professor at Yale University, noted that data shared as soon as in late May was evidencing that neither pregnant women nor their infants were at heightened risk of SARS-CoV-2 infection nor greater COVID-19 severity.

However, she expressed concern for pregnant women’s morbidity risk related to COVID-19.

“Women who had to get hospitalized for COVID-19 seem to have somewhat of a rockier course than women with COVID-19 who are not pregnant,” she said.

Minkin stressed clinicians being at the mercy of ever-developing understanding of SARS-CoV-2 infection and COVID-19 impact on populations like pregnant women and infants—and Salvatore’s team echoed a similar sentiment in their findings.

“The overall risk of COVID-19 infection due to in-utero or perinatal exposure for infants remains to be determined,” they wrote.

The study, "Neonatal management and outcomes during the COVID-19 pandemic: an observation cohort study," was published online in The Lancet Child & Adolescent Health.