absolute risks of venous thromboembolism according to COC (combined oral contraceptive pill)

Last reviewed 01/2018

Best estimates of the risk of VTE with a number of ethinylestradiol/progestogen combinations compared with the risk associated with levonorgestrel-containing pills are shown in table below. Compared with pregnancy and the postpartum period, the risk of VTE associated with using CHCs is lower.

Risk of VTE with combined hormonal contraceptives

Progestogen in CHC (combined with ethinylestradiol, unless stated) Relative risk vs levonorgestrel Estimated incidence (per 10,000 women per year of use)
Non-pregnant non-user - 2
Levonorgestrel Ref 5-7
Norgestimate / Norethisterone 1.0 5-7
Gestodene / Desogestrel / Drospirenone 1.5-2.0 9-12
Etonogestrel / Norelgestromin 1.0-2.0 6-12
Chlormadinone2 / Dienogest/ Nomegestrel acetate (E2) TBC TBC

E2 -estradiol; TBC -to be confirmed

1 Further studies are ongoing or planned to collect sufficient data to estimate the risk for these products

2 Not currently available in the UK

There is no evidence for differences between low dose CHCs (ethinylestradiol <50µg) in their risk of arterial thromboembolism (ATE).