Roughly half of all women who give birth don’t return for follow-up visits with their obstetricians after delivery. These postnatal visits are important for all women, especially those who experienced complications during pregnancy or childbirth. All women are at higher risk of stroke than men and that risk is especially high during and months after pregnancy. This risk can be accurately assessed on an individual basis only by a physician familiar with a patient’s pregnancy history.

Neurology specialist Dr. Hooman Kamel has discovered that the risk for blood clots doesn’t disappear in the delivery room but lingers as long as 12 weeks after delivery. Blood clots cause strokes and heart attacks which can be fatal or leave the patient permanently impaired.

Kamel, affiliated with the Weill Cornell Medical College in New York City, says the incidence of strokes after pregnancy is rare but the devastation they cause can have long-term effects on the patient’s quality of life. About 10% of pregnancy-related strokes are fatal. Women who survive strokes don’t recover from them as well as men do.

As delivery day approaches, a woman’s blood changes composition. The blood normally produces elements that make it clot to minimize damage from injury and to heal wounds. Production of these clotting compounds increases as delivery approaches so childbirth can occur with minimal loss of blood.

Dr. Andrew Sterner, a neurologist at Georgetown University in Washington, DC, addresses the mistaken notion that once delivery is over, the clotting factor reverts immediately to normal. It doesn’t. It takes a while to stabilize post-pregnancy production of clotting agents but the blood in the legs poses a separate risk.

Varicose veins occur when the structure of the blood veins in the legs weaken enough to cause the blood to pool. Vein strength is required to pump blood against gravity from the feet to the heart. When varicose veins occur deep in the legs, they aren’t usually visible although they can be painful. Clots can develop in these damaged veins and can break loose, travel to the heart, lungs, or head, where they block blood flow and cause strokes.

In Kamel’s study of 1.7 million first-time mothers in California, 1,015 of them developed clots during the first 18 months after delivery:


  • 248 caused strokes
  • 47 caused heart attacks
  • 720 had clots develop in the legs or lungs

Kamel found the risk during the first six months after delivery was 11 times higher than for other women. The risk fell to two times higher between weeks 7 to 12 post-delivery before leveling off to match the risk of women in the general population.

The typical adult does not know a clot has developed until a catastrophic event occurs. A doctor will know what tell-tale signs to look for, especially in follow-up visits after childbirth.

Source: “Risk of Serious Blood Clots Extends to 12 Weeks After Childbirth Researchers Find Risk Lasts Twice as Long as Previously Thought (press release).” Weill Cornell Medical College Newsroom. Weill Cornell Medical College. Feb 13, 2014. Web. Feb. 19, 2014.