Use of combined oral contraceptives and risk of venous thromboembolism in young women: a nested case-control analysis using German claims data.

Our study confirms that levonorgestrel with low ethinylestradiol (<50 μg) is the COC associated with the lowest risk of VTE and suggests that for chlormadinone the risk of VTE is two times higher, and thus in the same range as for desogestrel and drospirenone.