Table 2.
Male hormonal contraceptive efficacy trials
| Study, year published (Ref.) | No. of couples | Length of efficacy phase | No. of azoospermic men (%) | No. of oligo-spermic men (%) | No. of failures to suppressa (%) | No. of pregnancies (%) | Total no. of failuresb (%) | Overall contraceptive efficacy (95% CI) |
|---|---|---|---|---|---|---|---|---|
| WHO, 1996 (142) | 357 | 12 months | 268 (75) | 81 (23) | 8 (2.2) | 11 (3.1) | 19 (5.3) | 94.7 (92–97) |
| Gu et al., 2003 (217) | 305 | 6 months | 130 (43) | 166 (54) | 9 (2.9) | 1 (0.3) | 10 (3.3) | 96.7 (95–98) |
| Turner et al., 2003 (218) | 53 | 12 months | 49 (93) | 2 (3.6) | 2 (3.6) | 0 (0.0) | 2 (3.6) | 96.4 (91–100) |
| Total | 715 | 447 (62) | 249 (35) | 19 (2.6) | 12 (1.7) | 31 (4.4) | 95.7 (94–97) |
CI, Confidence interval.
a
To a sperm count less than 3–5 million, depending on study.
b
Defined as pregnancy and/or failure to suppress to enrollment in the efficacy phase.