COVID-19 March 27, 2020 Update
Two Research Letters published online March 26th in the JAMA described 3 cases of possible vertical transmission.1,2
In the first report,1 an infant girl was delivered by cesarean in a negative-pressure isolation room. She had no symptoms and was immediately quarantined. The mother with COVID-19 wore an N95 mask and did not hold the infant. Test results 2 hours after birth showed higher IgM antibody level. Because IgM antibodies do not usually appear until 3-7 days after infection and are not known to transfer to fetus via the placenta, this observation suggests that the infant was infected in utero.
The story is not as straightforward and is not conclusive. The infant was tested negatively repeatedly using throat swabs. It’s possible the test was not always reliable. Also, the placenta and amniotic fluid was not tested.
IgM was also detected in two neonates in the second report.2 Similarly, the cases aren’t as straightforward and more tests are needed.
In an Editorial3 addressing these two reports, JAMA applauded the efforts of these researchers especially during the difficult time. However, IgM assays can be prone to false-positive and false-negative results, therefore IgM is a challenging way to diagnose congenital infections.
The board concluded that “Although these 2 studies deserve careful evaluation, more definitive evidence is needed before the provocative findings they report can be used to counsel pregnant women that their fetuses are at risk from congenital infection with SARS-CoV-2.”3
- Dong L et al. Possible vertical transmission of SARS-CoV-2 from an infected mother to her newborn. JAMA. 2020.
- Zeng H et al. Antibodies in infants born to mothers with COVID-19 pneumonia. JAMA. 2020.
- Kimberlin DW et al. Can SARS-CoV-2 infection be acquired in utero?: More definitive evidence is needed. JAMA. 2020.
COVID-19 March 26, 2020 Update
Currently available data indicated there were no confirmed cases of intrauterine transmission of the novel coronavirus (SARS-CoV-2) from mothers with COVID-19 infection to their fetuses.1
The current pandemic has created anxiety and stress for women who are currently pregnant. Are they at increased risks of COVID-19 infection? As important, is there maternal-fetal transmission of the novel coronavirus? In the past, vertical maternal-fetal transmission has been seen with Zika virus and Ebola virus.2 So what about SARS-CoV-2?
This was the focus of a recent publication.1 At the time of the analysis, there were 38 pregnant women reported with COVID-19 infection from multiple hospitals near the epicenter of the pandemic in China. All were in the third trimester, and all but one were lab-confirmed cases of COVID-19. These pregnancies resulted in 39 infants; detailed clinical information including SARS-CoV-2 status were available from 30 infants.
The analysis found:1
- All infants were tested negative for SARS-CoV-2. In cases where placentas were also tested for the virus, the results were also negative.
- For the mothers, there were no cases of severe pneumonia or maternal death.
- Women with comorbid conditions, including those that were obstetrical in etiology, did not result in increased severity of COVID-19 infection.
These early data suggest no evidence of SARS-CoV-2 intrauterine or transplacental transmission from infected pregnant women to their fetuses. However, please note that the current sample size is very small, and all cases originated from one country.
These findings were published in mid-March 2020 in the journal Archives of Pathology & Laboratory Medicine.
What are the key takeaways?
- Currently, no vertical transmission of SARS-CoV-2 from infected pregnant women to fetuses has been seen
- Pregnant women with COVID-19 infection were not at higher risk for conditions such as preeclampsia, gestational diabetes, or premature delivery compared to pregnant women without COVID-19
- Nevertheless, be aware that newborn infants are not immune to the novel coronavirus and can still be infected upon close contact with those with confirmed COVID-19
As the novel coronavirus is spreading rapidly worldwide, the situation changes every single day. This update reflects current evidence at time of release. Metagenics Institute will follow the development closely and continue to provide updates according to new evidence. Additional info on pregnancy and breastfeeding during the pandemic is available on the CDC website.
- Schwartz DA. An analysis of 38 pregnant women with COVID-19, their newborn infants, and maternal-fetal transmission of SARS-CoV-2: maternal coronavirus infections and pregnancy outcomes. Arch Pathol Lab Med. 2020. [Epub ahead of print].
- Schwartz DA. The origins and emergence of Zika virus, the newest TORCH infection: what’s old is new again. Arch Pathol Lab Med. 2017;141:18-25.