Pregnancy, Preeclampsia, and COVID-19: Susceptibility and Mechanisms: A Review Study

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters cells through angiotensin converting enzyme  2 (ACE2), which expression of its gene increases during pregnancy that is resulted in an enhanced level of the ACE2  enzyme. It might enhance the risk of SARS-CoV-2 infection and its complications in the pregnant women. Although,  pregnancy hypertensive disorders and severe infection with SARS-CoV-2 are correlated with high comorbidity, these  two entities should be discriminated from each other. Also, there is a concern about the risk of preeclampsia and  consequently severe coronavirus disease 2019 (COVID-19) development in the pregnant women. So, to answer these  questions, in the present review the literature was surveyed. It seems there is higher severity of COVID-19 among  pregnant women than non-pregnant women and more adverse pregnancy outcomes among pregnant women infected  with SARS-CoV-2. In addition, an association between COVID-19 with preeclampsia and the role of preeclampsia  and gestational hypertension as risk factors for SARS-CoV-2 infection and its complications is suggested. However, infection of the placenta and the SARS-CoV-2 vertical transmission is rare. Various mechanisms could explain the role of COVID-19 in the risk of preeclampsia and association between preeclampsia and COVID-19. Suggested mechanisms are included decreased ACE2 activity and imbalance between Ang II and Ang-(1-7) in preeclampsia, association of both of severe forms of COVID-19 and pregnancy hypertensive disorders with comorbidity, and interaction between immune system, inflammatory cytokines and the renin angiotensin aldosterone system and its contribution to the hypertension pathogenesis. It is concluded that preeclampsia and gestational hypertension might be risk factors for SARS-CoV-2 infection and its complications.