The world suddenly came to a halt during the first few months of 2020, caused by the outbreak of the SARS-CoV-2 infection, also known as COVID-19 (fig. 1). Originating from Wuhan in the Chinese province of Hubei, the virus is known to cause a variety of illnesses, ranging from the lack of symptoms to causing severe acute respiratory distress syndrome (ARDS) and death. Several hundreds of pregnant women have been infected with SARS-CoV-2, but the consequences of the disease on mother and baby are currently (as of October 2020) unknown. While there have been individual cases that have been studied to analyze how the virus affects pregnant women, there had not been any published papers conducting a study on a larger population until October 2020 by Rong Yang¹. 

In the previously mentioned individual case studies, the newborns from COVID-19 positive mothers tested negative for COVID-19 and another study shows that there is no evidence of virus transmission from the mother’s blood or placenta to the newborn^2,3. This is known as in-utero vertical transmission. However, another study by Lingkong Zeng⁴ showed that 2 out of the 6 newborns in the study had antibodies against the virus, which implies virus exposure in the womb. Again, it is essential to note that these studies were conducted on a small scale, with a sample size of fewer than 10 people. It is always better to conduct a study on a larger sample to ensure that the results apply to a wide range of people.

In Yang’s study, they used the Maternal and Child Health Information Management System of Wuhan (MCHIMS) to collect data on routine maternal and newborn health, as well as any data on COVID-19 diagnoses and outcomes. They chose 11,078 women that gave birth to a single newborn between January 12, 2020 and March 18, 2020 (fig. 2). Out of the 11,078 women, 65 were diagnosed with COVID-19, but the researchers were only able to contact 58 out of the 65 women to conduct a phone interview. Out of those 58 women, 38 newborns were tested and found to be negative for COVID-19, while the other 20 newborns were not tested for the virus. Additionally, 30 newborns had chest CT scans that did not show signs of SARS-CoV-2 infection, 3 newborns had a fever, and 1 had diarrhea (fig. 3).

While there were no deaths reported, the study found an increased risk of preterm birth (birth before 37 weeks of pregnancy) and cesarean deliveries due to COVID-19 complications such as oxygen deprivation in the uterus¹. The infection rate of pregnant women was also reported to be similar to the infection rate of the general population of Wuhan, so it is reasonable to conclude that pregnant women are not more susceptible to the disease. This study also found no evidence of vertical transmission of SARS-CoV-2 because all newborns born to COVID-19 positive mothers tested negative, but the previously mentioned antibodies would need to be studied more thoroughly. 

Although this study was published in October 2020, it is essential to note that the data was taken from the first few weeks of the pandemic, and therefore, the conclusions made were derived from very early information. As we continue to learn about SARS-CoV-2, it is possible that the conclusions made from this study may need to be amended.

References

1. Yang, R., Mei, H., et. al. Pregnant women with COVID-19 and risk of adverse birth outcomes and maternal-fetal vertical transmission: a population-based cohort study in Wuhan, China. BMC Medicine. 2020;18(1):330.

2. Fan. C., Lei, D., et. al. Perinatal transmission of COVID-19 associated SARS-CoV-2: should we worry? Clin Infect Dis. 2020; ciaa226.

3. Chen, H., Guo, J., et. al. Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records. Lancet. 2020;395(10226):809-15.

4. Zeng, L., Xia, S., et. al. Neonatal early-onset infection with SARS-CoV-2 in 33 neonates born to mothers with COVID-19 in Wuhan, China. JAMA Pediatr. 2020;174(7):722-5.