Which clotting factor is NOT decreased in pregnancy?

In pregnancy, the hemostatic system undergoes various adaptations to prepare for childbirth and reduce the risk of hemorrhage. While many clotting factors increase or remain stable, some do decrease.

Factor V is one of the clotting factors that remains stable during pregnancy. It plays a central role in the coagulation cascade, ultimately promoting the conversion of prothrombin to thrombin. Maintaining adequate levels of Factor V is crucial because it contributes to a balanced hemostatic environment as the body prepares for delivery.

In contrast, other factors like Protein S typically decrease during pregnancy. This decrease is significant as Protein S acts as a cofactor to Protein C, which serves to inhibit clotting factors Va and VIIIa, thereby regulating coagulation. Similarly, Factor XI and Factor XIII also show decreased levels during pregnancy, reflecting a complex interplay of hemostatic changes.

Understanding these variations is essential for healthcare providers who manage pregnant patients, especially in assessing their risk for thromboembolic events or bleeding complications during and after delivery.