Relative risk of continuing pregnancy following early medical abortion with different forms of contraception provided at the time of misoprostol administration (n=4838)
| Method of contraception | Number of women (%) (n=4838) | Number of women using method with gestation at presentation ≥8 weeks (%) | Number of women using method who had previous abortion (%) | Number of continuing pregnancies (n=20) | Relative risk (RR) of continuing (95% CI) |
| Combined contraceptive* | 1268 (26.2) | 229 (18.1) | 382 (30.1) | 5 | 0.90 (0.29 to 2.73) |
| Progestogen-only pills | 485 (10.0) | 90 (18.6) | 146 (30.1) | 3 | 1.40 (0.37 to 5.26) |
| Progestogen-only implant | 797 (16.5) | 125 (15.7) | 225 (28.2) | 3 | 0.85 (0.23 to 3.21) |
| Depot medroxyprogesterone acetate | 475 (9.8) | 102 (21.5) | 141 (29.7) | 1 | 0.48 (0.06 to 3.81) |
| None/barrier method/fast track*† | 1813 (37.5) | 328 (18.1) | 570 (31.4) | 8 | 1.00 (Ref.) |
*Number of women using the following methods: combined oral contraception=1182 (pill=1181, patch=79 and ring=8); none=976; condoms=433; diaphragm=2; copper intrauterine device=185; levonorgestrel intrauterine system=215; laparoscopic sterilisation=2.
†Women receiving fast-track service for intrauterine device/system (2-week appointment) were not given an interim method by the abortion services therefore they can be grouped with ‘no hormonal contraception’.
Ref., reference.