Physiological, mechanical, and immunologic alterations in pregnancy could potentially affect the susceptibility to and the severity of COVID-19 during pregnancy. Owing to the lack of comparable incidence data and the challenges with disentangling differences in the susceptibility from different exposure risks, the data are insufficient to determine whether pregnancy increases the susceptibility to SARS-CoV-2 infection. The data support pregnancy as a risk factor for severe disease associated with COVID-19; some of the best evidence comes from the United States Centers for Disease Control and Prevention COVID-19 surveillance system, which reported that pregnant persons were more likely to be admitted to an intensive care unit, require invasive ventilation, require extracorporeal membrane oxygenation, and die than nonpregnant women of reproductive age. Although the intrauterine transmission of SARS-CoV-2 has been documented, it appears to be rare. It is possibly related to low levels of SARS-CoV-2 viremia and the decreased coexpression of angiotensin-converting enzyme 2 and transmembrane serine protease 2 needed for SARS-CoV-2 entry into cells in the placenta. Evidence is accumulating that SARS-CoV-2 infection during pregnancy is associated with a number of adverse pregnancy outcomes including preeclampsia, preterm birth, and stillbirth, especially among pregnant persons with severe COVID-19 disease. In addition to the direct impact of COVID-19 on pregnancy outcomes, there is evidence that the pandemic and its effects on healthcare systems have had adverse effects such as increased stillbirths and maternal deaths on the pregnancy outcomes. These trends may represent widening disparities and an alarming reversal of recent improvements in maternal and infant health. All the 3 COVID-19 vaccines currently available in the United States can be administered to pregnant or lactating persons, with no preference for the vaccine type. Although the safety data in pregnancy are rapidly accumulating and no safety signals in pregnancy have been detected, additional information about the birth outcomes, particularly among persons vaccinated earlier in pregnancy, are needed.
Keywords: COVID-19; SARS-CoV-2; fetal death; fetus; maternal death; newborn; perinatal infection; pneumonia; pregnancy; preterm birth; vertical transmission.
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