Starting depot medroxyprogesterone contraception
Depot medroxyprogesterone can be started at any stage of the menstrual cycle. If early pregnancy cannot be excluded (for general advice about excluding pregnancy, see Starting intrauterine contraception), a pregnancy test is recommended 4 weeks after starting, or 3 weeks after starting if no further episodes of unprotected sex occurred in the first week of use.
Depot medroxyprogesterone is immediately effective if:
- started on day 1 to 5 of a regular menstrual cycle
- started less than 21 days postpartum
- started within 5 days of an abortion
- repeating the depot medroxyprogesterone injection
- switching from an etonogestrel implant
- switching from a copper IUD during days 1 to 5 of a regular menstrual cycle.
Depot medroxyprogesterone takes 7 days to become effective at all other times, and if the current method of contraception is not effective at the time of switching (eg late doses, injection or replacement).
If switching from a combined oral contraceptive or vaginal ring, continue active hormone pills or the vaginal ring for a further 7 days after insertion to prevent potential pregnancy from previous intercourse. For more information about time to effectiveness when switching between contraceptive methods, see printable table.
Use:
medroxyprogesterone 150 mg by deep intramuscular injection, every 12 weeks. contraception medroxyprogesterone
The preferred site of injection of depot medroxyprogesterone is the gluteal muscle, but injection into the deltoid muscle may be given (eg if there is deep adipose tissue in the gluteal area).
Assess risk factors for low bone mineral density and cardiovascular disease annually in users of depot medroxyprogesterone.
Bleeding patterns cannot be readily interpreted to assess the likelihood of pregnancy when a repeat depot medroxyprogesterone injection is delayed. Pregnancy can be excluded if it is more than 14 weeks since the last injection, but:
- there has been no unprotected sex since injection was due
- the last episode of unprotected sex since injection was due was more than 3 weeks ago and a urine pregnancy test is negative.
Repeat the injection; it will be effective in 7 days.
If a urine pregnancy test is negative but the last episode of unprotected sex occurred less than 3 weeks ago, offer Quick Start. Alternatively, give the next depot injection when pregnancy can be excluded (by a further negative urine pregnancy test performed 3 weeks after the last episode of unprotected sex). Offer levonorgestrel emergency contraception if unprotected sex has taken place in the last 4 days.