"Our research shows that normal women have small anomalies in their pelvic MRIs after delivering a baby, but this was a small study and we don't know what these anomalies are. They may be small natural blood clots, or they may simply be artifacts of the test," Dr. Marc Rodger told Reuters Health by email.

"We will need to do more research to figure this out," he added, "but in the meantime, I do not believe that it is something that pregnant women or their doctors should worry about."

Dr. Rodger of the University of Ottawa and colleagues note that venous thromboembolism, although rare, is the leading cause of direct maternal mortality in the developed world.

The researchers included 30 women in what they say is the first study of the incidence and natural history of intraluminal filling defects in the postpartum period in low-risk patients.

At a median of one day postpartum, 30% of the women had definite thrombosis (all in the iliac and ovarian veins). A further 27% had "probable" thrombosis and another 10% had "possible" thrombosis, the authors reported online January 16 in the American Journal of Obstetrics and Gynecology.

Thus, the researchers conclude, "some degree of pelvic vein intraluminal filling defect may be a normal finding after uncomplicated vaginal delivery."

Dr. Andra H. James of Duke University Medical Center in Durham, North Carolina, author of an editorial published with the paper, agrees, telling Reuters Health by email, "The best explanation for the investigators' observation of a high incidence of nonocclusive pelvic thrombosis in the early postpartum period is that this is a normal physiological process that has previously been poorly described."

"At present," Dr. James concluded, "their findings should not change current practice, but thanks to the investigators, we have new insights and a number of additional questions to answer regarding the evolution of postpartum blood clots."

By David Douglas

Source: http://bit.ly/yY2UZ5

Am J Obstet Gynecol 2012.

Last Updated: 2012-02-23 17:56:24 -0400 (Reuters Health)

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