Possible intrauterine infection: Positive nucleic acid testing results and consecutive positive SARS-CoV-2-specific antibody levels within 50 days after birth

Gao, Jinzhi; Hu, Xiaolin; Sun, Xuan; Luo, Xiaoping; Chen, Ling

Whether SARS-CoV-2 affects fetus in utero is important to the well-being of mother and neonate. We report a full-term neonate born to the mother who developed symptoms of COVID-19 at 32-week gestational age. The placental pathology showed local slight inflammation. Serial quantitative antibody measurements in the neonate showed the level of IgM was elevated at the day of birth and gradually declined to negative within 28 days of life, the levels of IgG declined gradually but still positive at 50th day of life. The dynamic change trend of antibody levels in the neonate was consistent with that in his mother. One-step Reverse Transcriptase-droplet digital Polymerase Chain Reaction for SARS-CoV-2 nucleic acid testing from throat and anal swabs showed positive results (750 and 892 copies/ml) at 7th day of life and negative results at 14th day of life. The neonate had no symptom of COVID-19. This report enables us to reevaluate the significance of IgM detection in intrauterine infection of SARS-CoV-2, and presents a favorable prognosis in the neonate with long-term exposure to maternal COVID-19, despite great possibility of intrauterine infection.