Table 2.
Risk of Venous Thromboembolism among Combined Oral Contraceptive Users According to the Type of Progestin
| Variable | VTE risk, RR (95% CI) |
|---|---|
| Second-generation | |
| Levonorgestrel | 1 |
|
| |
| Third-generation | |
| Norgestimate | 1.14 (0.94–1.32)a |
| Gestodene | 1.67 (1.32–2.10)a |
| 1.27 (1.15–1.4)b | |
| Desogestrel | 1.83 (1.55–2.13)a |
| 1.46 (1.33–1.59)b | |
|
| |
| Fourth-generation | |
| Drospirenone | 1.58 (1.12–2.14)a |
| 1.40 (1.26–1.56)b | |
| Cyproterone acetate | 2.04 (1.55–2.49)a |
| 1.29 (1.12–1.49)b | |
| Dienogest | 1.46 (0.57–5.41)a |
VTE, venous thromboembolism; RR, relative risk; CI, confidence interval.
The estimated RR for VTE for 1 year of combined oral contraceptive use was provided from the meta-analyses by aDragoman et al. [42] and bOedingen et al. [48], respectively, in comparison to levonorgestrel. Data on VTE risk were obtained from the general population, and the absolute risk of VTE is low (8–10/10,000 woman-years).