Reportedly, pulmonary embolism has overtaken all other causes of maternal mortality in the past two to three decades. Research from a thirty-year study just published in the Annals of Internal Medicine indicates that pregnant women and those up to three months postpartum are four times more likely than other women to suffer pulmonary embolism or a similarly dangerous blood clot, deep-vein thrombosis. Note, however, that the long-term study focused on women in a single county in Minnesota, and 98% of the subjects were white and non-Hispanic. It is unclear whether results would vary for women of different ethnicities.
Dr. Gary Hankins, chair of the American College of Obstetricians and Gynecologists committee that is creating guidelines based on this research, recommends that new moms get up and walk as soon as possible in order to prevent such clots. In certain cases, doctors may suggest leg-compression devices as well. Obviously, this is general advice and you should discuss such matters with your own physician.