Clinical implications
The healthy neonatal outcomes reported in the study occurred despite the placental injury, which may be caused by the redundancy built into placentas for delivering oxygen and nutrients and for removing waste.
The negative COVID-19 test results in all infants also supports existing evidence that vertical transmission of the virus is uncommon. The finding also suggests that any damage to the placenta is likely related to maternal infection.
Only one mother in the COVID-19 cohort was hypertensive, which surprised the researchers because intervillous thrombi have been associated with maternal high blood pressure. “In the context of research suggesting an increase of thrombotic and thromboembolic disorders in COVID-19,” the researchers noted, “these may represent placental formation or deposition of thrombi in response to the virus.”
One of the priorities for the researchers going forward is to monitor the longer-term outcomes of the infants, Dr. Goldstein said. “We know the people in utero during the 1918-1919 flu pandemic had higher rates of heart disease and other long-term problems, so we want to be on the lookout for something similar.”
Valuable insight
“This is a comprehensive case series of this topic, with findings worth noting and sharing in a timely fashion,” Karen Mestan, MD, associate professor of pediatrics within the division of neonatology at Northwestern University, said when asked to comment on the study.
“The information is valuable to neonatologists as the short- and long-term effects of COVID-19 exposure on newborn infants are still largely unknown,” she added. “Details of placental pathology provide emerging insight and may help us understand mother-baby vertical transmission during the current pandemic.”
Dr. Goldstein and Dr. Mestan had no relevant financial disclosures.
SOURCE: Shanes ED et al. Am J Clin Pathol. 2020 May 22. doi: 10.1093/ajcp/aqaa089.
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