dcyphr | Antibodies in Infants Born to Mothers With COVID-19 Pneumonia


In February 2020, there were available tests for IgG and IgM antibodies for SARS-CoV-2 (severe acute respiratory syndrome coronavirus). The National Health Commission of the People’s Republic of China added serological tests as a diagnostic criteria for COVID-19. Previous studies show there is no evidence of antibody transmission from mother to infant for mothers with COVID-19. In this study, they added serological tests to examine how newborns are affected.


Researchers took throat swabs and blood samples of mothers and used neonatal blood samples. They took chest computed tomography (CT) scans and used RT-PCR. They tested for antibodies in neonatal sera.


Researchers tested 6 mothers with COVID-19 symptoms. Babies were delivered by cesarean sections, and they had high Apgar scores of 8 to 10 after one and five minutes. This means the babies were healthy. Two infants had elevated IgG and IgM levels. Their mothers also had a corresponding increase in these antibodies. Three infants had increased IgG levels but not IgM levels. Two of their mothers had increases in both antibodies and one had only increased IgG. All infants had a slightly increased level inflammatory cytokine IL-6. None of the infants had COVID-19 symptoms.


IgG can pass through the placenta from mother to the infant but IgM cannot. Another study showed mothers recovering from the SARS-CoV in their third trimester had abnormal placenta pathology. Researchers do not know about the pathology of placentas in this study. Another possibility is that the virus passed through the placenta, and the baby made IgM antibodies. This study has an extremely small data size. The quality of the data is limited by the quality of the samples. Data is still incomplete, and more research needs to be done.