Some contraceptive pills more likely to cause blood clots

Certain contraceptive pills are more likely to cause serious blood clots, new research says. One such clot is VTE or venous thromboembolism. This forms in the deep veins in one leg and may travel to the lungs, which can prove fatal in one out of three people.
http://ummid.com/news/2011/October/28.10.2011/pills_cause_blood_clots.htm