starting progestogen-only injectable contraception post other form of contraception
Last edited 08/2019
Advice in relation to switching from other form of contraception to progestogen-only contraceptive injections (1,2,3)
| Situation | Starting | Additional contraceptive protection required? | Additional information |
| Switching from combined hormonal contraception (CHC) (if taken correctly) | Day 1-2 of the hormone free interval (HFI) | No | |
| Switching from CHC (if taken correctly) | Day 3-7 of HFI OR week 1 following the HFI | Yes (7 days). If unprotected sexual intercourse (UPSI) has occurred after Day 3 of the HFI, advise continuing the CHC method for at least 7 days | When switching after a 7-day HFI there are no data to confirm that suppression of ovulation is maintained |
| Switching from CHC (if taken correctly) | Week 2-3 of pill/ring/patch | No, providing the CHC method has been used consistently and correctly for 7 consecutive days before switchin | There is evidence to suggest that taking hormonally active pills for 7 consecutive days prevents ovulation. Therefore as long as there have been 7 days of CHC use, 7 hormone-free days can occur without any effect on contraceptive efficacy |
| Switching from traditional POP (if taken correctly) OR LNG-IUS | Any time | Yes (7 days) If UPSI in last 7 days, retain LNG IUS for 7 days after starting injectable | The continuing method provides contraceptive cover while the effects of the injectable are established |
| Switching from desogestrel POP (if taken correctly) OR progestogen-only implant (<=3 years since implant insertion) | Any time | No | |
| >3 years since implant insertion | Any time | Yes (7 days) | If there has been a risk of pregnancy consider the need for emergency contraception (EC) and a pregnancy test (PT) no sooner than 3 weeks after the most recent incidence of UPSI |
| Switching from Cu-IUD | Day 1-5 of menstrual cycle | No | |
| Switching from Cu-IUD | Any other time | Yes (7 days). If UPSI in last 7 days, retain Cu-IUD for 7 days |
CHC, combined hormonal contraception; Cu-IUD, copper intrauterine device; EC, emergency contraception; HFI, hormone free interval; POP, progestogen-only pill; PT, pregnancy test; UPSI, unprotected sexual intercourse
Consideration of EC and a pregnancy test no sooner than 3 weeks after the most recent incidence of UPSI may be required if there has been a risk of pregnancy (3).
The summary of product characteristics must be consulted before prescribing any of the drugs described.
Reference:
- Prescriber (2001);12 (5): 83-95.
- Guillebaud J. Contraception: your questions answered. 3 rd edition. London: Churchill Livingston, 1999
- FSRH (April 2019). Progestogen-only Injectable Contraception