**2. Epidemiology of VTE in pregnancy and puerperium**

Women during pregnancy and the immediate puerperal period are considered at risk for VTE and there is a substantially higher prevalence that in non-pregnant women of the same age. A case-control study reported that compared with nonpregnant women, the risk of VTE was increased five-fold during pregnancy, and by 60-fold during the first three months after birth. However the absolute risk remains low, estimated at around one to two in 1000 pregnancies [6, 7].

The incidence of VTE, especially Pulmonary Embolism (PE), is believed to be much higher during the immediate puerperal period - mostly associated with cesarean section - with between 40% and 60% of all acute PE cases reported to occur postpartum(with a estimated 15-fold increased risk of PE postpartum compared with during pregnancy). In a systematic review the risk of VTE was fourfold greater following CS than following uncomplicated vaginal delivery; and was greater following emergency CS than following elective CS. On average, was estimated that three in 1,000 women will develop a VTE following CS [6, 7].

However a decline overall in deaths associated with VTE in recent years has been observed since publication and more adherence to prevention guidelines for obstetric population [2, 6].

Currently there one reported study on incidence of Deep venous thrombosis (DVT) in women receiving thromboprophylaxis using heparin after CS. This study found that the incidence of asymptomatic DVT among women at high risk of VTE was 3.9%. In patients without thromboprophylaxis symptomatic DVT was detected in 0.04% and 0.5% [7–9].
