Table 3. The risk of venous thromboembolism associated with various types of combined oral contraceptive*1 (Red Hand Letter, December 2018).
| Gestagen |
Relative risk (compared to levonorgestrel) |
Estimated incidence per 10 000 patient-years |
| Non-pregnant non-users | – | 2 |
| Levonorgestrel | Reference | 5–7 |
| Norgestimate/norethisterone | 1.0 | 5–7 |
| Dienogest | 1.6 | 8–11 |
| Gestodene/desogestrel/ drospirenone |
1.5–2.0 | 9–12 |
| Etonogestrel/norelgestromin | 1.0–2.0 | 6–12 |
| Chlormadinone acetate /nomegestrol acetate (e2) | yet to be confirmed*2 |
yet to be confirmed*2 |
E2, estradiol
*1 Red Hand Letter on combined hormonal contraceptives – updated for dienogest/ethinyl estradiol, December 2018
*2 Further studies are in progress to provide adequate data on the risks associated with
these preparations.