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.
Can You Have a Healthy Pregnancy With Factor V Leiden?
Yes. Most women with Factor V Leiden go on to have healthy pregnancies and healthy babies. Carrying the mutation is far more common than most people expect, and many women who have it never experience a clot at all. What matters is knowing about it, because a diagnosis allows your care team to watch for problems and start preventive treatment when it is warranted rather than reacting after a complication develops.
Your individual risk depends on details like whether you inherited the mutation from one parent or both, whether you have had a clot before, and whether you have other risk factors such as a prior pregnancy loss. Two women with the same diagnosis can need very different care plans, which is why a personalized evaluation matters more than a general statistic.
Who Should Be Tested for a Clotting Disorder?
Not every pregnant woman needs testing for clotting disorders, but your provider may recommend it based on your personal or family history. Testing is generally considered if you have experienced recurrent miscarriages (typically two or more), a previous blood clot in your legs or lungs, a prior pregnancy complicated by severe preeclampsia or unexplained poor fetal growth, or a strong family history of clotting events.
Testing usually involves blood work that looks for specific gene mutations (like Factor V Leiden or prothrombin mutation) and checks for the antibodies associated with antiphospholipid syndrome. Your provider may recommend testing during preconception counseling or early in the first trimester so that a treatment plan can be put in place as soon as possible.
How Are Blood Clotting Disorders Treated During Pregnancy?
The primary treatment for clotting disorders in pregnancy is blood thinner therapy, most commonly with a medication called low-molecular-weight heparin (such as enoxaparin). This type of blood thinner does not cross the placenta, making it safe for your baby. Depending on your specific diagnosis and risk level, your provider may prescribe daily injections throughout pregnancy and for several weeks after delivery.
For women with antiphospholipid syndrome, treatment often includes both low-dose aspirin and blood thinner injections. The combination has been shown to significantly improve pregnancy outcomes in women with APS.
Managing blood thinners through delivery requires careful planning. Your care team will coordinate the timing of your last injection before delivery to reduce bleeding risks, and they will advise you on when to restart the medication afterward. This coordination is one of the reasons that having a specialized care team matters so much.
Clotting Disorder Care in Las Vegas, Henderson, and Reno
Clotting disorders in pregnancy require close collaboration between your OB/GYN, your maternal-fetal medicine specialist, and sometimes a hematologist. At the High Risk Pregnancy Center, our board-certified maternal-fetal medicine specialists focus on complex pregnancies like these. Through pregnancy team management, we coordinate with all of your providers to make sure nothing falls through the cracks, from adjusting your medication dosage to scheduling frequent ultrasounds that track your baby’s growth.
With advanced diagnostic testing, comprehensive monitoring, and a team available 24/7, we are built to support women who need more than standard prenatal care.
If you have a history of blood clots, recurrent pregnancy loss, or a known clotting disorder and are pregnant or planning to become pregnant, schedule an appointment at the High Risk Pregnancy Center. Call (702) 382-3200 or request an appointment online to get started.
