An issue of the novel coronavirus infection spreading is currently in the first place among others in the list of the international medical community. Due to lack of information, conflicting research findings, multicomponent effect of the virus on the body host, as well as various consequences that the virus triggers in the body, now every medical specialty does study the viral attack pathogenesis. Recent months showed that vascular complications are the most severe in the Coronavirus Disease 2019 (COVID-19) and are the main cause of death in the patients. The mechanisms of vascular complications are complex and affect both the hemostatic system and immune responses, "inflammatory storm", disorders of the renin-angiotensin-aldosterone system, endotheliopathy, etc. Due to the leading role of vascular complications in the viral infection pathogenesis, several groups of patients are at extra risk, including pregnant women, patients with a burdened obstetric history, with hereditary thrombophilia and antiphospholipid syndrome, and patients after in vitro fertilization (IVF). In this category of pregnant women, use of low-molecular-weight heparins (LMWH) is particularly important for both prevention of vascular and obstetric complications, and for pathogenetic therapy of COVID-19.