There are now more than 15 million confirmed cases of Covid-19 worldwide. The disease has reached 190 countries, with the US being the most affected. According to the US Centers for Disease Control and Prevention (CDC), the majority of confirmed cases are in seen in adults ages 18–64 years. Among adults aged 18–44 years, pregnant women are considered to be a vulnerable group due to the immunologic and physiologic changes experienced during pregnancy that can increase the risk for severe illness from respiratory infections. CDC data indicate that in the US, pregnant women account for approximately 4% of the total population. Although data on Covid-19 in pregnant women has been limited, it is important to understand how infection affects pregnant women, as it could provide insight on how the disease affects the immune system and could guide prenatal care.
From January 22 to June 7, the CDC collected data on more than 326,000 women of reproductive age (15–44 years) who had positive lab results for SARS-CoV-2, the virus that causes Covid-19. The results showed that pregnant women with the disease were more likely to be hospitalised, be admitted to the intensive care unit (ICU), and need mechanical ventilation than non-pregnant women with Covid-19 of the same age. This increased risk of ICU admission and mechanical ventilation may be partially due to the fact that pregnant women with Covid-19 more frequently reported an underlying chronic condition such as diabetes. However, data on whether the chronic condition was present before the infection occurred was unavailable. Among women ages 15–44 with the disease, pregnancy was not associated with an increased risk for mortality. This study’s findings suggest there may be a difference in disease severity between pregnant and non-pregnant women with Covid-19.
A systematic review looking at pregnancy outcomes in women with Covid-19, severe acute respiratory syndrome (SARS), or the Middle East respiratory syndrome (MERS) found similar outcomes in terms of ICU admission and hospitalisation rates. Other findings from the systematic review showed that pregnant women with Covid-19, SARS, or MERS were more likely to have preterm births, pre-eclampsia, and caesarian delivery when compared to pregnant women without the diseases. Understanding the outcomes of pregnancy in Covid-19-positive women is important because it could prevent adverse outcomes on a large scale. Often the effects of a new disease during pregnancy are not understood until a large group of newborns is affected. This was the case during the Zika virus disease epidemic, which peaked in August 2016. Approximately six months later, areas of widespread local transmission recorded a peak in birth defects linked to the Zika virus infection (CDC, 2020). However, more data collection on pregnant women with Covid-19 is necessary to understand the progression of the illness in pregnant women and their risk for developing severe illness. Continued collection of longitudinal data can shed light on the immune response that the disease triggers in pregnant women and can lead to a better understanding of the health outcomes in mothers and newborn children. It is especially important to look into the effects of pregnancy in Covid-19-positive mothers since previous viral outbreaks such as SARS, MERS, and Zika, which were associated with serious conditions requiring ICU admission and birth defects, did not reach the magnitude of the current pandemic. Therefore, any postnatal outcomes associated with the disease will be seen on a global scale.
Figure 1: Age Distribution of Confirmed Cases of Covid-19 in Pregnant and Non-pregnant Women in the US, Ages 15–44 Years, %, 2020.
Credit: GlobalData; Ellington et al, 2020.