Pulmonary embolism during pregnancy and the postpartum period

Abstract

Pregnancy and the postpartum period are known risk factors for venous thromboembolism (VTE) [1]. In pregnancy, VTE can be observed as lower extremity deep vein thrombosis (DVT) alone, as well as together with pulmonary embolism (PE). The incidence rate of VTE is 4-50 times higher in pregnant women compared to non-pregnant women of the same age [2]. The risk increases especially in the postpartum period [3]. Over the last 15 years, there has been a 4.6-fold increase in the number of pulmonary thromboembolism (PTE) patients [4]. The most important causes of this increase can be listed as fast-food nutritional habit, obesity, prolongation of human lifetime and technological improvements in diagnostic processes. Physiological causes that increase the probability of VTE development during pregnancy and in the postpartum period are: (1) Thrombocyte activation, reduced fibrinolytic and protein S activities, (2) Relaxation effect of progesterone secretion on venous smooth muscles during pregnancy, (3) Estrogen causing an increase in levels of procoagulant factors [5-8], (4) Decrease of anticoagulant factors-protein S and antithrombin levels-via estrogen, (5) Compression effect of the uterus during pregnancy on the iliac vein and inferior vena cava, (6) Vascular intimal injury due to surgical applications such as cesarean, forceps and vacuum, (7) Stasis due to immobility during pregnancy and the postpartum period, (8) Genetic factors such as deficiencies of protein S, Protein C and antithrombin leading to thrombophilia, (9) Maternal age of 35 years and above, (10) VTE history prior to the pregnancy, (11) Obesity (BMI ≥ 30 kg/m2), heart disease, sickle cell disease and systemic lupus erythematosus, and (12) Multiparas and delivery by caesarean section [9, 10].