Tennis star Serena Williams has revealed that she experienced potentially life-threatening blood clots after giving birth to her daughter last year. But why does giving birth increase a woman’s risk of blood clots?
Williams needed an emergency cesarean section to delivery her baby, Alexis Olympia Ohanian Jr., in September 2017, according to Vogue magazine. That surgery went well, but soon “everything went bad,” Williams told Vogue.
It’s known that a woman’s risk of blood clots increases during pregnancyand shortly after giving birth. In fact, a woman’s risk of blood clots is about four to five times higher when she is pregnant, compared with when she’s not pregnant, said Dr. Saima Aftab, medical director of the Fetal Care Center at Nicklaus Children’s Hospital in Miami, who is not involved with Williams’ care.
“Pregnancy is pretty much a very risky time period” for blood clots, Aftab told Live Science.
And this risk doesn’t go away immediately after a woman gives birth — her risk for blood clots remains elevated for about six weeks after giving birth, according to the Centers for Disease Control and Prevention. That’s because it takes time for the blood-clotting factors to return to normal, and for the uterus to reduce in size, Aftab said. And just as in late pregnancy, women may be less mobile in the first week or two after childbirth, she said.
Having a C-section further increases the risk of blood clots, as does any surgery. A 2016 study found that women who give birth via C-section are about four times more likely to develop blood clots, compared with women who give birth vaginally.
About 1 to 2 out of every 1,000 pregnant women experience a blood clot, according to Medscape. Women who have a history of blood clots, as Williams does, are at higher risk of blood clots during pregnancy and childbirth than women without a history of blood clots.
Blood clots in pregnancy tend to form in the deep veins of the legs or pelvis — a condition known as deep vein thrombosis, according to the American Society of Hematology. Pulmonary embolisms can occur when these clots break off and travel to the lungs.
The American College of Obstetricians and Gynecologists (ACOG) recommends that women with a history of blood clots use an anti-clotting medication to prevent blood clots during pregnancy. ACOG also recommends placing inflatable compression devices on a woman’s legs during a C-section to prevent clots, and leaving them in place until the woman can walk again.
It’s also important that pregnant women be on the lookout for signs of a blood clot, such as pain or swelling in the legs, particularly in the left leg, Aftab said.
And if patients experience shortness of breath and chest pain, doctors should take this seriously and evaluate them quickly, because it could be a sign of a life-threatening pulmonary embolism, Aftab said.
Original article on Live Science.