DMPA Subcutaneous Injection

Depot medroxyprogesterone acetate (DMPA) subcutaneous is a progestin-only injectable containing medroxyprogesterone acetate 104 mg, supplied as a prefilled single-use injection system and given under the skin every 13 weeks. It has the same contraceptive action as the intramuscular form and can be self-administered by trained patients.

Mechanism. Ovulation suppression, thickened cervical mucus and endometrial thinning.

Pharmacokinetics. The subcutaneous depot releases slowly over the interval. The 104 mg dose is lower than the 150 mg intramuscular dose with comparable ovulation suppression.

Effectiveness. Typical use: 4 pregnancies in 100 women in the first year. Perfect use: 0.2 in 100.

Return to fertility. Delayed for four months or longer after the last injection, and in some patients up to 12 months.

Ideal candidates. Patients who want a private three-monthly method, those with access barriers to frequent clinic visits, and those who can learn self-injection.

Assessment. Menstrual, obstetric, breastfeeding and medicine history, blood pressure, and the ability to inject. No pelvic or breast examination or laboratory test is needed. Offer HIV testing. Exclude pregnancy by the usual criteria, with a test if none applies.

Eligibility. The categories match intramuscular DMPA.

• Category 1: BMI 30 or more; smoking; HIV; epilepsy and rifampicin or rifabutin use; sickle cell disease; breastfeeding from 6 weeks.
• Category 2: under 18 or over 45 years; controlled hypertension; past deep vein thrombosis; high HIV acquisition risk; antiretroviral therapy with efavirenz, nevirapine or ritonavir-boosted regimens.
• Category 3: breastfeeding under 6 weeks; ischaemic heart disease or stroke; blood pressure 160/100 mm Hg or more; acute deep vein thrombosis or pulmonary embolism; severe cirrhosis or liver tumour; unexplained bleeding before evaluation; lupus with positive or unknown antiphospholipid antibodies; past breast cancer.
• Category 4: current breast cancer.

Counselling. Consent, confidentiality, absence of coercion and assent of adolescents under 18 years. Explain bleeding change, delayed fertility, slight bone density reduction without an age or duration limit, and condoms for infection protection.

Regimen.

• Medroxyprogesterone acetate 104 mg prefilled single-use injection system, subcutaneous injection into the abdomen or front of the thigh, every 13 weeks.
• Start within 7 days of menses without backup; later, backup for 7 days.
• Grace window: up to 2 weeks early and up to 4 weeks late without backup.
• Over 4 weeks late: exclude pregnancy, give provider-administered intramuscular DMPA in place of self-injection, and use backup for 7 days.
• Switching from another hormonal method used correctly: inject at once. From another injectable, inject when the repeat injection is due.
• No dose change for body weight, liver disease or enzyme inducers.
• Storage: cool, dry place away from children.

Technique. Wash hands, check the expiry date and the packaging, shake for 30 seconds, activate the system, clean the site, pinch the skin, insert the needle at a downward angle until the port touches the skin, then squeeze the reservoir slowly over 5 to 7 seconds. Do not massage the site.

Start timing. Postpartum, breastfeeding women start from 6 weeks; non-breastfeeding women at once or within 21 days, and later after excluding pregnancy with backup for 7 days. After abortion start within 7 days, or later with backup for 7 days.

Self-injection and follow up. The first self-injection is supervised. Up to 4 doses may be dispensed at once, with a facility visit at least yearly. Return used systems for safe disposal. Reviews cover bleeding, blood pressure and weight.

Expected effects. Bleeding changes (irregular early, amenorrhoea in most by a year), weight change, headache, dizziness, mood swings, bloating, acne, breast tenderness. Injection site reactions include pain, skin discolouration or dimpling.

Bleeding management.

• Persistent spotting with no pathology: ibuprofen 400 to 800 mg orally three times daily with food for 7 to 14 days, maximum 2400 mg in 24 hours; avoid in peptic ulcer, renal impairment, severe liver disease and NSAID-sensitive asthma.
• Heavy or prolonged bleeding: exclude gynaecological disease, then ibuprofen 400 to 800 mg orally three times daily with food for 7 to 14 days (maximum 2400 mg in 24 hours) or a combined oral contraceptive, one active tablet daily for 1 to 3 cycles, if oestrogen is not contraindicated and not breastfeeding under 6 months.
• Persistent unacceptable bleeding: stop and offer another method.

Other problems. Reassure amenorrhoea; test for pregnancy if in doubt. Check blood pressure for headache and refer severe headache. Treat or refer a persistent injection site reaction.

Red flags. Severe lower abdominal pain (exclude ectopic pregnancy), jaundice, chest pain, calf swelling, severe headache.

Referral and escalation. Refer unexplained bleeding for examination and cervical screening. Refer pregnancy for antenatal care.