COVID-19 Infection during Pregnancy: Risk of Vertical Transmission, Fetal, and Neonatal Outcomes

Abstract

The COVID-19 pandemic is a worldwide, critical public health challenge and is considered one of the most communicable diseases that the world had faced so far. Response and symptoms associated with COVID-19 vary between the different cases recorded, but it is amply described that symptoms become more aggressive in subjects with a weaker immune system. This includes older subjects, patients with chronic diseases, patients with immunosuppression treatment, and pregnant women. Pregnant women are receiving more attention not only because of their altered physiological and immunological function but also for the potential risk of viral vertical transmission to the fetus or infant. However, very limited data about the impact of maternal infection during pregnancy, such as the possibility of vertical transmission in utero, during birth, or via breastfeeding, is available. Moreover, the impact of infection on the newborn in the short and long term remains poorly understood. Therefore, it is vital to collect and analyze data from pregnant women infected with COVID-19 to understand the viral pathophysiology during pregnancy and its effects on the offspring. In this article, we review the current knowledge about pre-and post-natal COVID-19 infection, and we discuss whether vertical transmission takes place in pregnant women infected with the virus and what are the current recommendations that pregnant women should follow in order to be protected from the virus.

Keywords: ACE-2 receptor; SARS-CoV-2; coronavirus; immune response; placental antibody transfer; pregnancy outcomes.

Figure 1

COVID-19 infection during pregnancy. Schematic model presenting the relationship between COVID-19 and pregnant women. Pregnant women acquire COVID-19 via respiratory droplets. COVID-19 is spread throughout the maternal vasculature and the symptoms appear after an incubation period of approximately 5.2 days. The most common symptoms of COVID-19 are fever, dry cough, fatigue, diarrhea, and myalgia. The impact of COVID-19 infection on pregnancy outcomes are not established. However, COVID-19 infection effects newborn health (shortness of breath, fever, and thrombocytopenia accompanied by abnormal liver function, rapid heart rate, vomiting, pneumothorax, etc.). So far, the vertical transmission from the woman to her baby may be possible, but no data related to the risks of transmission of COVID-19 infection through breastfeeding were recorded. Specific precautions (wash hands carefully and regularly, cover nose and mouth with a tissue when coughing or sneezing, avoid touching eyes, nose and mouth, maintain a distance of at least 1 m from others, etc.) are needed to protect both the mother and her baby. Figure was created with BioRender.com (accessed date 5 January 2021).

Figure 2

SARS-CoV-19 structure, host cell entry, and replication model. SARS-CoV-2 binds to host cells through the ACE-2 receptor, and, after uncoating, the components of virion use the host cell’s machinery to produce new viruses. Finally, the SARS-CoV-2 virions are released from the host cell by exocytosis.

Figure 3

Vertical transmission rate of COVID-19 to neonates based on different testing sites and meta-data analysis of 38 studies. IgM, immunoglobulin M; NP, nasopharyngeal; COVID-19, coronavirus disease 2019.