A new study published in the online edition of the New England Journal of Medicine suggests that the risk of blood clots that may cause strokes and heart attacks in women is high for up to 12 weeks after child birth, twice as long as previous estimates.
Researchers led by Dr Hooman Kamel, from New York's Weill Cornell Medical College, observed more than 1.7 million women in California who gave birth to their first child and found that more than 1,000 of them developed blood clots over the next 18 months.
Around 248 of them suffered from strokes, 47 had heart attacks and 720 had clots in the legs or lungs. The researchers also found that the risk of such problems was 11 times greater during the first six weeks after delivery and more than two times greater during weeks seven to 12.
"While rare, blood clots are a serious cause of disability and death in pregnant and post-partum women, and many members of our research team have cared for young women with these complications. If you have recently delivered a baby, seek medical attention if you develop symptoms such as: chest pain or pressure; difficulty breathing; swelling or pain in one leg; sudden severe headache; or sudden loss of speech, vision, balance, or strength on one side of your body", Dr Kamel said.