C-Section Births Significantly Raise Blood Clot Risk

Pregnancy increases the risk of deep vein thrombosis (DVT) due to blockage of blood flow, and having a C-section can significantly increase that risk.

The risk of thromboembolism, a potentially deadly condition in which organs sustain damage due to the blockage of blood flow by blood clots, has been found to greatly increase during pregnancy. And according to experts at the American College of Obstetricians and Gynecologists, having a Caesarean section (C-section) birth almost doubles that blood clot risk.

The significant increase in risk for blood clots has prompted the leading obstetricians group to issue a new recommendation that all women undergoing a C-section should wear inflatable compression devices on their legs during delivery to prevent the formation of blood clots.

In addition, for cases in which the risk is greatest, the group advised that these women also receive anticoagulant (anti-clotting) medications. The new guidelines will be published in an upcoming issue of Obstetrics & Gynecology.

Dr. Andra H. James, who was involved in the development of the new guidelines, stated in a college news release, “VTE [venous thromboembolism] is a major contributor to maternal mortality in this country. The risk of VTE is increased during pregnancy and the consequences can be severe.” She then added, “It’s important for ob-gyns to adopt these recommendations to help reduce maternal deaths.”

Several physiological changes that pregnant women experience put them at greater risk for developing VTE, such as a slowing of blood flow, having blood that tends to clot more easily, decreased mobility, and compression of pelvic and other veins. Other factors that increase the risk for VTE include obesity, a history of VTE or extreme clotting, high blood pressure, and smoking.

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James explained, “Fitting inflatable compression devices on a woman’s legs before cesarean delivery is a safe, potentially cost-effective preventive intervention…. Inflatable compression sleeves should be left in place until a woman is able to walk after delivery or - in women who had been on blood thinners during pregnancy - until anticoagulation medication is resumed.” However, in the case of emergency C-sections, delaying delivery for placement of the devices must be avoided.

The authors noted that women having a history of VTE during pregnancy, or a history of excessive clotting, as well as those at an increased risk for inherited clotting disorders, should receive anti-clotting medication.

The authors also cautioned that all women who have undergone C-sections also need to be monitored for the development of VTE post delivery. James said, “Because half of VTE-related maternal deaths occur during pregnancy and the rest during the postpartum period, ongoing patient assessment is imperative. While warning signs in some women may be evident early in pregnancy, others will develop symptoms that manifest later in pregnancy or after the baby is born.”