Reply.

We greatly appreciate the interest in our work and the opportunity to respond to the issues raised. The letters by Sriwijitalai and Wiwanitkit and by Li and colleagues raise the issue of transplacental transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). , Since the publication of our paper online on February 24, 2020, several papers addressing this issue have been published, including a paper by Vivanti et al that provides strong evidence for transplacental transmission of SARS-CoV-2. In this case report, the mother presented to the hospital at 35 weeks’ gestation with symptoms of coronavirus disease 2019 (COVID-19), and her nasopharyngeal and vaginal swabs, blood, amniotic fluid, and placenta all tested positive for SARS-CoV-2. She gave birth via cesarean delivery to a neonate who required intubation for 6 hours because of low Apgar scores. The baby’s blood, bronchoalveolar lavage, and nasopharyngeal and rectal swabs were all positive for SARS-CoV-2 on day of life (DOL) 1, with nasopharyngeal and rectal swabs also positive on DOL 3 and DOL 18. The neonate developed neurologic symptoms on DOL 3, and brain magnetic resonance imaging showed white matter gliosis on DOL 11. The test result of the cerebrospinal fluid sample was negative for SARS-CoV-2. Thus, based on recent evidence, it appears that transplacental transmission of SARS-CoV-2 can occur, although it appears to be rare; however, its effects on the newborn remain unclear.

The letter by Liauw and colleagues raises the issue of antenatal corticosteroids. Since our paper was published, additional evidence regarding corticosteroids has become available, including a controlled trial in which patients with severe COVID-19 (those receiving respiratory support) who were treated with dexamethasone had significantly lower mortality than those who received usual care. Thus, the concern about corticosteroid use in patients with COVID-19 is no longer relevant; consistent with the guidelines developed by the American College of Obstetricians and Gynecologists, corticosteroid administration is recommended for pregnant women at risk of preterm delivery to improve neonatal outcomes.

The response to COVID-19 continues to be a rapidly evolving situation, and as we continue to learn more, we anticipate that guidance will continue to change. It is therefore critical that clinicians keep abreast of current developments.