Transmission of SARS-CoV-2 from mothers to neonates is rare, two new studies say. One study, from the New York-Presbyterian Morgan Stanley Children's Hospital and New York-Presbyterian Allen Hospital, evaluated vertical transmission among 101 newborns born to 100 mothers with perinatal SARS-CoV-2 infection. Most infants (90.1%) were born to asymptomatic/mildly symptomatic mothers, but 10 were born to mothers with severe/critical COVID-19 disease. The 101 neonates had 141 tests for SARS-CoV-2. No SARS-CoV-2 viral RNA was detected in 135 specimens. Initial results of 4 specimens were deemed invalid. Two tests in 2 newborns had indeterminate results, and only 1 of these infants underwent retesting and had negative results, according to the online report published Monday in JAMA Pediatrics. Neither of the infants with indeterminate results and none of the infants who tested negative developed symptoms of COVID-19. Considering these 2 indeterminate results as positives, the overall incidence of transmission was 2.0%. "The most surprising finding was that despite a 2% positive testing based rate of vertical/perinatal transmission, none of our babies exhibited clinical symptoms of COVID-19, either during their newborn nursery stay or during their follow up for those that were seen within our medical system for routine and non-routine visits within the first few weeks of life," Dr. Dani Dumitriu from New York-Presbyterian/Columbia University Irving Medical Center, New York told Reuters Health by email. Nineteen of the newborns were admitted to the neonatal intensive care unit (NICU) for reasons unrelated to maternal SARS-CoV-2 infection. Among the 23 newborns seen in the COVID-19 newborn follow-up clinic or elsewhere, 6 underwent retesting for SARS-CoV-2, and all findings were negative. In a separate study published on Monday in Nature Communications, Italian researchers analyzed maternal and newborns nasopharyngeal swabs, vaginal swabs, maternal and umbilical cord plasma, placenta and umbilical cord biopsies, amniotic fluids and milk from 31 mothers with SARS-CoV-2 infection. They detected the virus in one umbilical cord blood specimen, two at-term placentas, one vaginal mucosa and one milk specimen. They also identified IgM and IgG antibodies in one umbilical cord blood sample and in one milk specimen. In three documented cases of vertical transmission, SARS-CoV-2 infection was accompanied by a strong inflammatory response. "These data support the hypothesis that in utero SARS-CoV-2 vertical transmission, while low, is possible," the authors said. Dr. Cynthia Gyamfi-Bannerman, a coauthor of the New York City paper, told Reuters Health by email, "Our findings underscore the need to diligently study and report on outcomes and generate data to evidence guidelines, particularly as some of the protocols initially put into place regarding separation had the potential for a negative effect on bonding and other mother-child outcomes." Her team noted in their report that despite the negative findings among these infants, 27 were bathed earlier than the 24th hour of life. Most newborns (91/101) breastfed at least partially (41 were breastfed exclusively or mostly). Another of the New York authors, Dr. Melissa Stockwell, told Reuters Health by email, "As the country heads into what looks like a second wave of the COVID-19 pandemic, it is important to know that separation of affected mothers from their newborns may not be warranted, and direct breastfeeding appears to be safe." "Acquisition of SARS-CoV-2 from infected mothers at delivery appears to be infrequent, and the risk of severe illness among newborns who are infected in the perinatal or immediate postnatal period appears infrequent as well," write Dr. David W. Kimberlin from University of Alabama at Birmingham, Birmingham, Alabama and Dr. Karen M. Puopolo from University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania in a JAMA Pediatrics editorial. "On the other hand, the difficulties of separating newborns from their mothers, which were appreciated from the outset, certainly have not lessened and if anything have increased as the pandemic continues to expand." "The balance between these risks has greater clarity now and will be considered when revisions are made to neonatal management guidance," they conclude. —Will Boggs MD Source
