March 26, 2020

Clinical symptoms from neonates born to mothers with COVID-19, and possible vertical transmission of SARS-CoV-2

By Denise Baez

NEW YORK -- March 26, 2020 -- In today’s DG Alert, we cover clinical symptoms and outcomes from neonates born to mothers with coronavirus disease 2019 (COVID-19) in Wuhan, China, and the possibility of vertical transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

The clinical symptoms from 33 neonates with, or at risk, of COVID-19 were mild and outcomes were favourable, with only 3 infants showing symptoms of SARS-CoV-2 infection, according to a study published in JAMA Pediatrics.

All neonates were born to mothers with COVID-19 and recruited from Wuhan Children’s Hospital, with data collected between January 2020 and February 2020. Lingkong Zeng, MD, Wuhan Children’s Hospital, and colleagues focused on the 3 infants presenting with early-onset SARS-CoV-2 infection. All 3 infants were delivered by caesarean section.

In the first case, caesarean delivery was performed because of meconium-stained amniotic fluid and confirmed maternal COVID-19 pneumonia. On day 2 of life, the infant experienced lethargy and fever, but physical examination was normal. The infant was moved to the neonatal intensive care unit (NICU). A chest radiographic image showed pneumonia, but other laboratory tests (except procalcitonin) were normal. Nasopharyngeal and anal swabs were positive for SARS-CoV-2 on days 2 and 4 of life and negative on day 6.

Infant 2 was also delivered by caesarean because of confirmed maternal COVID-19 pneumonia. He presented with lethargy, vomiting, and fever. Physical examination was unremarkable. Laboratory tests showed leucocytosis, lymphocytopenia, and an elevated creatine kinase-MB fraction. A chest radiographic image showed pneumonia. Nasopharyngeal and anal swabs were positive for SARS-CoV-2 on days 2 and 4 of life and negative on day 6.

Infant 3 was delivered by caesarean because of fetal distress and confirmed maternal COVID-19 pneumonia. Resuscitation was required. The infant’s Apgar scores were 3, 4, and 5 at 1, 5, and 10 minutes after birth, respectively. Neonatal respiratory distress syndrome and pneumonia was confirmed by chest radiograph, and resolved on day 14 of life after treatment with non-invasive ventilation, caffeine, and antibiotics. He also had suspected sepsis, leucocytosis, thrombocytopenia, and coagulopathy, which improved with antibiotic treatment. Nasopharyngeal and anal swabs were positive for SARS-CoV-2 on days 2 and 4 of life and negative on day 7.

“Because strict infection control and prevention procedures were implemented during the delivery, it is likely that the sources of SARS-CoV-2 in the neonates’ upper respiratory tracts or anuses were maternal in origin,” the authors noted. “Vertical maternal-fetal transmission cannot be ruled out in the current cohort.”

In related news, a case report published in JAMA describes a neonate, born to a mother with COVID-19, with elevated antibody levels and abnormal cytokine test results 2 hours after birth, suggesting that the neonate was infected in utero.

The infant girl was delivered on February 22, 2020, to a woman aged 29 years with laboratory-confirmed COVID-19. The caesarean delivery was done in a negative-pressure isolation room. The mother wore an N95 mask and did not hold the infant. The neonate had no symptoms and was immediately quarantined in the NICU. At 2 hours of age, the SARS-CoV-2 IgG level was 140.32 AU/mL and the IgM level was 45.83 AU/mL. Cytokines and white blood cell counts were elevated. Chest CT was normal. Results from 5 RT-PCR tests on nasopharyngeal swabs taken from 2 hours to 16 days of age were negative; however, IgM (11.75 AU/mL) and IgG (69.94 AU/mL) levels were still elevated on March 7. She was discharged on March 18.

“IgM antibodies are not transferred to the fetus via the placenta,” wrote Lan Dong, MD, Renmin Hospital of Wuhan University, and colleagues. “The infant potentially could have been exposed for 23 days from the time of the mother’s diagnosis of COVID-19 to delivery. Although infection at delivery cannot be ruled out, IgM antibodies usually do not appear until 3 to 7 days after infection, and the elevated IgM in the neonate was evident in a blood sample drawn 2 hours after birth. Also, the mother’s vaginal secretions were negative for SARS-CoV-2. The infant’s repeatedly negative RT-PCR test results on nasopharyngeal swabs are difficult to explain, although these tests are not always positive with infection. IgG antibodies can be transmitted to the fetus through the placenta and appear later than IgM. Therefore, the elevated IgG level may reflect maternal or infant infection.”