How Common Are Blood Clots, DVT and Pulmonary Embolisms During Pregnancy?

Pregnancy brings about all kind of pesky side effects. Most of them are innocuous… like ptyalism, which is the name for the excessive saliva that some pregnant women produce in the first trimester. There are, however, some side effects that can be very serious if left untreated, so it’s imperative to know the warning signs. Blood clots, DVT and pulmonary embolisms in particularly can be very problematic and are far more common than you might thing as women are more prone to them when pregnant.

To learn more we spoke with Dr. Vonne Jones, MD, an OB/GYN providing care to women at Total Women’s Care, in Houston, TX.

Momtastic: How common are blood clots, DVT, and pulmonary embolisms during pregnancy?

Dr. Vonne Jones: Because pregnancy is what we call a pro-coagula state, meaning that there’s an increased chance of patients having clots during the process of pregnancy just because of the kind of vascular changes that happen at the level of the vessel, women have a four to fivefold increase risk of having what we call a thromboembolism, which is either a DVT, which is a clot within the leg, or a PE, which is a pulmonary embolism and a clot within the lungs.

Momtastic: Can you touch a little bit on what causes each of them?

Dr. Vonne Jones: The causes are typically the same. If there’s, what we call a hyper-coagula state there are increased proteins within the vessels that allow for clotting. So the biggest risk factors are going to be moms that are not active. Sometimes, for various potential reasons, a mom can be put on bed rest and that’s a big risk factor for clots to form during pregnancy. Moms that are obese, that’s another risk factor for thromboembolism or DVT during pregnancy. If you have a history of clots prior to pregnancy, DVTs and that’s also going to be a risk factor as well. Moms that have any type of blood disorders, von Willebrand factor, protein c protein, protein s deficiency and any type of history of lupus – those are all risk factors. Hypertension and diabetics can also be at increased risk of clots. So there’s a large group of patients that are pregnant that could be at increased risk of developing clots in the legs or in the lungs.

Momtastic: What are the warning signs of these?

Dr. Vonne Jones: Warning signs are going to be when you’re looking specifically at the DVT, sometimes patients can feel a lump right behind the knee, which is where the calf is – most of the time the clots are there, but they can also be within the lower extremity by the ankle or anywhere that the vessel tracks upward from the knee up to the upper leg. So if you’re looking for pain, sometimes you can see redness on the actual calf itself. The other thing that patients notice sometimes is a lot of swelling; it’s really important to look into whether a patient is having swelling just because of pregnancy versus a patient having swelling because of a DVT that’s formed within the calf. Sometimes you can notice there’s a difference in the swelling, there may be one leg that’s more swollen than the other, you might have some pain in that leg that is new and different from typical swelling and pain that you have in general during pregnancy, especially in that third trimester.

If you’re looking for pulmonary embolism symptoms, typically shortness of breath and what we call tachycardia or increased heart rate – think sudden onset shortness of breath and increased heart rate or increased pulse, typically 113 or higher.

Momtastic: What are the potential dangers of each?

Dr. Vonne Jones: Untreated the DVT can travel, break off and go to the lungs and cause a pulmonary embolism. If a pulmonary embolism is substantial and is not treated, then there’s an increased risk of maternal death because of it. So the clot by itself within the leg, if it’s not treated, it can sometimes move, it can move anywhere because it’s in the vein, it can move up into the heart, into the lungs and it can cause cardiovascular issues, but if it’s a drastic or a large clot and it can be fatal for moms.

Momtastic: Any tips for prevention?

Dr. Vonne Jones: The biggest thing that I would say is, earlier we talked about people that are at increased risk for clots, this population, perhaps, especially if they’re on medication, I would say it would be very important to see an obstetrician prior to pregnancy, so that you can come in, we can go over all of the past medical histories that you have, and different things may need to change in order to get pregnant. For example,  sometimes patients that have lupus are taking blood thinners like Lovenox and it may need to be a different dose to decrease those chances of having clots.

In general, I tell all my patients to eat as clean as possible – fruits, vegetables, lean meats, all of these different things – but also be active. The more active you are and you’re not sedentary, then that is going to bode well for you during the pregnancy and it’s going to decrease the chances of you developing clots in the legs and in the lungs.

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