FFinalistSouthampton · 2027
Obstetrics & gynaecology
AKT · Obstetrics & gynaecology/Contraceptionlow yield

Depot injection (DMPA)

Depot medroxyprogesterone acetate — 13-weekly progestogen

Overview

A progestogen depot injection (medroxyprogesterone acetate) every 13 weeks that inhibits ovulation. Effective and discreet, but unique among methods for a reversible reduction in bone mineral density and for delaying the return of fertility by up to a year.

Recognise

  • IM/SC every 13 weeks; inhibits ovulation
  • Often causes amenorrhoea (a benefit for many)
  • Reversible reduction in bone mineral density (recovers after stopping)
  • Delayed return of fertility — up to ~1 year after the last injection
  • Weight gain is associated

Red flags

  • UKMEC: caution if multiple osteoporosis risk factors; age 45 are relative cautions; current breast cancer (UKMEC 4)

Differentials & how to tell them apart

Contraceptive implantprogestogen LARC but NO bone-density loss and NO fertility delay — preferred if those matter
Progestogen-only pilldaily oral progestogen; no BMD concern
Levonorgestrel IUSintrauterine; lightens periods, no BMD loss

Investigations

History (osteoporosis risk, age, pregnancy plans); exclude pregnancy. No oestrogen/BP concern.

Management

13-weekly progestogen injection when a discreet, non-daily method is wanted (mind BMD/fertility delay)

  1. 1Offer to women wanting a discreet 13-weekly method; counsel re amenorrhoea, weight gain, BMD and delayed fertility return.Gate: Significant osteoporosis risk factors, or planning pregnancy soon → choose another method (BMD loss + up to 1-year fertility delay)
  2. 2Review bone-density risk on continuation, especially in adolescents and women >45y.
Medroxyprogesterone acetate (Depo-Provera / Sayana Press) — every 13 weeks; the SC version can be self-administered

Key points

The only method with a meaningful (reversible) effect on bone density and a prolonged delay in fertility return — both classic exam discriminators against the implant.

Monitor & prognosis

Re-injection at 13 weeks; BMD risk review on long-term use.

Reversible, but fertility return is delayed up to ~1 year.

Source: FSRH UKMEC 2016; FSRH progestogen-only injectable guidance