1 INTRODUCTION

The first case of coronavirus virus disease 2019 (COVID‐19) was revealed in Wuhan in December 20191; the virus spread in China and then globally.2 According to the increasing growth rate of coronavirus cases, this outbreak was declared a Public Health Emergency of International Concern on January 30, 2020, by the WHO Emergency Committee.3

The most frequent symptoms in mild and moderate cases of COVID‐19 were fever, anosmia, or shortness of breath, which appears to be more frequent in adults than children, as well as cough, dyspnea, and myalgia, among other clinical features.4 The laboratory abnormalities included increased values of C‐reactive protein, erythrocyte sedimentation rate, lactate dehydrogenase, and D‐dimer.4, 5 According to the meta‐analysis of AJ Rodriguez‐Morales et al,5 lymphopenia was detected in more than 40% of patients. The frequency of lymphopenia found suggests that COVID‐19 acted on T lymphocytes, as does SARS‐CoV, maybe including depletion of CD4 and CD8 cells.5 Virus particles spread through the respiratory mucosa, initially using the ACE2 receptor at ciliated bronchial epithelial cells, and then infect other cells, which causes a “cytokine storm” in the body and generates a series of immune responses.6 The “cytokine storm” with a hyper‐innate inflammatory response in the lungs of COVID‐19 patients is driven mostly by the IL‐6, which is produced by monocytes and macrophages7-9 and may serve as a predictive biomarker for disease severity9 or a target for the therapy development.8, 10

Because of the immune reaction severity, 20.3% of COVID‐19 patients required intensive care unit, 32.8% presented with acute respiratory distress syndrome (ARDS), 6.2% with shock.5 It has been shown that ARDS occurs even when the viral load decreases,11, 12 which suggests that the over‐reactivity of the immune system and not the action of the virus are responsible for the occurrence of ARDS, and the attenuation of the “cytokine storm” by targeting several key steps in the process could bring about improved outcomes.8, 10, 13

In this regard, the urgent question that needs to be addressed promptly includes whether pregnant women with COVID‐19 will develop distinct symptoms from non‐pregnant and what are the reasons for that. This is of particular relevance to the fact that pregnant women infected with other respiratory viruses, for example, H1N1 influenza, Zika virus, and SARS‐CoV were reported with more fetal adverse events.14