To the Editor We read with interest the article by Zeng et al1 that reported on 33 neonates of women infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during pregnancy, where 3 of 33 had early-onset SARS-CoV-2 infection. The 3 affected neonates were born 1 to 3 days after their mothers were diagnosed as having SARS-CoV-2, developed symptoms within the first 2 days of life, and had positive SARS-CoV-2 polymerase chain reaction from nasopharyngeal and anal samples on days 2 and 4 of life. It is unclear whether these infants were infected intrauterine or after birth, especially because it is not yet known whether viremia precedes clinical manifestations of SARS-CoV-2 infection. Detection of anti–SARS-CoV-2 IgM in cord and/or early-life neonatal blood could have supported intrauterine infection because neonatal IgM is not transplacentally transferred from the mother and is of fetal origin.2 The distinction between intrauterine vs postnatal infection is critical. With other infections, intrauterine infection can lead to severe consequences in the developing fetus, including blindness, developmental delay, or neurologic manifestations,3 depending on timing of infection during pregnancy and the infectious pathogen (eg, neonatal microcephaly associated with Zika virus during pregnancy). However, postnatal Zika infection is not associated with congenital anomalies and would be expected to cause a primarily mild infection.
Abu Raya B, Giles ML, Sadarangani M. Vertical Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 From the Mother to the Infant. JAMA Pediatr. 2020;174(10):1007–1008. doi:10.1001/jamapediatrics.2020.2150
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