Blood clotting disorders, also called thrombophilias, are conditions that cause your blood to clot more easily than it should. During pregnancy, your body naturally increases its clotting ability to prepare for delivery. But for women with an underlying clotting disorder, this normal shift can tip the balance toward dangerous complications like blood clots in the legs or lungs, recurrent miscarriage, placental problems, and preeclampsia.
Understanding whether you have a clotting disorder and how it affects pregnancy is an important step toward protecting the health of both you and your baby.
Types of Clotting Disorders: Factor V Leiden, Prothrombin, and APS
Clotting disorders fall into two main categories: inherited and acquired. Inherited disorders are genetic conditions you are born with, while acquired disorders develop over time, often related to your immune system.
Factor V Leiden is the most common inherited clotting disorder and is caused by a gene mutation that makes your blood more prone to forming clots. Prothrombin gene mutation (Factor II) is another inherited condition that increases clot risk. Other inherited thrombophilias include deficiencies in proteins C and S, and antithrombin, all of which normally help regulate clotting.
On the acquired side, antiphospholipid syndrome (APS) is one of the most significant clotting disorders in pregnancy. APS is an autoimmune condition in which your body produces antibodies that attack certain proteins in your blood, increasing the tendency to form clots. APS is a well-known cause of recurrent pregnancy loss, and it can also contribute to preeclampsia, poor fetal growth, and preterm delivery.
How Do Blood Clotting Disorders Affect Pregnancy and Your Baby?
Pregnancy already puts extra demand on your circulatory system. Your blood volume increases significantly, and your body produces more clotting factors to reduce the risk of bleeding during and after delivery. For most women this process works as intended, but for those with thrombophilia, the added clotting tendency can lead to serious problems.
Blood clots can form in the deep veins of the legs, a condition called deep vein thrombosis (DVT). If a clot breaks loose and travels to the lungs, it becomes a pulmonary embolism, which is a medical emergency. Clotting problems can also affect blood flow through the placenta, potentially leading to miscarriage, stillbirth, fetal growth restriction, or placental abruption, where the placenta separates from the uterine wall before delivery.
