New Mothers May Need Longer Monitoring for Blood Clots

Blood clot risk remained elevated for up to 12 weeks after giving birth

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) It is normal for new mothers to be at risk for a blood clot for six weeks after giving birth. However, a new study suggests that women may still be at risk after those first six weeks.

A recent study found that women were at an increased risk of developing a blood clot for about three months after giving birth.

The researchers suggested that doctors take this lengthened risk into consideration when evaluating and treating symptoms of blood clots.

"Discuss any symptoms associated with blood clots after giving birth."

The lead author of this study was Hooman Kamel, MD, from the Department of Neurology and the Brain and Mind Research Institute of Weill Cornell Medical College in New York City.

The study included 648,148 women who were hospitalized for a blood clot between 2007 and 2011.

All participants received care from nonfederal emergency departments and hospitals in California.

The researchers used insurance claims and hospital records to see how many of the participants had given birth during this time.

Then, Dr. Kamel and team determined the likelihood of developing a blood clot at 0-6 weeks, 6-12 weeks, 12-18 weeks and 18-24 weeks after giving birth.

The likelihood of a woman developing a blood clot a year prior to giving birth was used as the comparison.

The findings showed that 1,620 participants had delivered a baby within the prior 24 weeks of developing a blood clot.

The average age of these participants was 30 years old, 16 percent were black and 35 percent were Hispanic.

The researchers determined that the participants were 6.6 times more likely to develop a blood clot in the 0-6 week period after giving birth than during the year prior to giving birth.

The risk of developing a blood clot was increased by 2.3 times during the 6-12 week period after giving birth compared to a year prior to giving birth.

By the 12-18 week period after giving birth, participants were only at a 20 percent increased risk of developing a blood clot compared to the year prior to giving birth.

By the 18-24 week period, the risk of developing a blood clot was not affected anymore by giving birth.

"Pregnancy has always been considered a period in time that women are at increased risk of developing thrombotic events or 'blood clots'," said Andre Hall, MD, an OBGYN at Birth and Women's Care, PA in Fayetteville, NC. "Six weeks after delivery has generally been considered the time in which women return to their baseline risk."

According to Dr. Hall, "This study challenges that timeline and asserts a longer period in which women should be monitored. The take home message here is that regardless of where you are time wise in relation to your delivery, if a recently postpartum patient has a fever, pain, swelling, or knots in an area of the body, she should seek medical attention for appropriate care of what could be a life threatening condition."

This study was presented on February 13 at the International Stroke Conference 2014.

The National Institute of Neurological Disorders and Stroke provided funding.

Review Date: 
February 12, 2014
Last Updated:
February 13, 2014