Clinical overview
Contraception is among the highest-impact interventions in women's health: it prevents unintended pregnancy and unsafe abortion, allows pregnancy spacing, and reduces maternal mortality. In South Africa, where the HIV and sexually transmitted infection burden is high and unintended pregnancy is common, contraceptive counselling carries an extra dimension — dual protection — and the public sector provides the full range of methods free of charge. This is an HOTS objective because the task is rarely "which method is best" in the abstract; it is matching the right method to the individual woman, integrating her reproductive intentions, her medical eligibility, her STI/HIV risk, her tolerance of bleeding changes, and her own preferences, through genuine shared decision-making.
Two frameworks anchor safe prescribing. Effectiveness is best understood in tiers, and counselling should be honest about the gap between perfect and typical use — the latter is what actually determines pregnancy rates, and it is why the long-acting reversible contraceptives (LARC) — the implant and intrauterine methods — are so dominant: they are "fit-and-forget" and remove the adherence burden. Eligibility is governed by the WHO Medical Eligibility Criteria (MEC), now in its 6th edition (2025), which classifies each method against each condition as Category 1 (no restriction), 2 (advantages generally outweigh risks), 3 (risks generally outweigh advantages — use only if better options unavailable), or 4 (unacceptable health risk — do not use). South Africa's National Contraception Clinical Guidelines (2019) localise this, and the UK FSRH UKMEC is a useful cross-reference. This chapter compares the modalities by mechanism, effectiveness, benefits, risks, and eligibility, then sets out how to choose. It links to postpartum-contraception, hiv-counselling, osteoporosis (DMPA and bone), heavy-menstrual-bleeding-management (the LNG-IUS), and termination-of-pregnancy.
Core knowledge
Effectiveness tiers (typical-use failure in the first year)
| Tier | Methods | Typical-use failure |
|---|---|---|
| Most effective | Implant, LNG-IUS, copper IUD, female & male sterilisation | <1 per 100 |
| Moderately effective | DMPA/NET-EN injectable, COC pill, progestogen-only pill, patch, vaginal ring | ~6–9 per 100 |
| Less effective | Male/female condoms, diaphragm, fertility awareness, withdrawal, spermicide | ~13–21 per 100 |
The implant and IUDs sit in the top tier because their effectiveness does not depend on the user remembering anything — typical and perfect use are nearly identical. For the injectable, pill, patch and ring, the difference between perfect and typical use is large and adherence-driven.
Figure B4.1 — Contraception map comparing typical-use effectiveness, duration, mechanisms, and key counselling trade-offs.
Combined hormonal contraception (CHC) — pill, patch, vaginal ring
- Composition/mechanism: ethinylestradiol (or newer oestrogens) plus a progestogen. Primary action is suppression of ovulation (inhibits the FSH/LH surge); they also thicken cervical mucus and thin the endometrium.
- Non-contraceptive benefits: predictable, lighter, less painful periods; improvement in acne and hirsutism (useful in hyperandrogenism); reduced functional ovarian cysts; and a durable reduction in ovarian and endometrial cancer risk.
- Risks: a 3–5-fold relative increase in venous thromboembolism (highest in the first year; drospirenone- and third-generation–progestogen pills carry slightly higher VTE risk than levonorgestrel pills), and increased arterial risk (MI, ischaemic stroke) especially in smokers over 35 and in uncontrolled hypertension.
- MEC Category 4 (do not use) examples: migraine with aura, smoking ≥15/day at age ≥35, BP ≥160/100, current/past VTE, known thrombogenic mutation, <6 weeks postpartum and breastfeeding, current breast cancer, complicated valvular heart disease, and active liver disease.
Progestogen-only pill (POP)
- Mechanism: traditional POPs act mainly by thickening cervical mucus (a strict 3-hour late-pill window); the desogestrel POP also inhibits ovulation and has a more forgiving 12-hour window.
- Use: excellent when oestrogen is contraindicated (VTE risk, migraine with aura, smokers >35, breastfeeding). Main side effect is unpredictable bleeding.
Progestogen-only injectables — DMPA and NET-EN
- Regimens: DMPA 150 mg IM (or 104 mg SC) every 12–13 weeks; NET-EN 200 mg IM every 8 weeks. Mechanism is ovulation inhibition.
- Strengths: highly effective, private, non-oestrogen, and independent of enzyme-inducing drugs.
- Drawbacks: delayed return of fertility (up to ~1 year after the last DMPA injection — counsel so this is not mistaken for infertility), a reversible reduction in bone mineral density (relevant in adolescents accruing peak bone mass and around the menopause — see osteoporosis), weight gain, and bleeding changes progressing to amenorrhoea.
- HIV: the ECHO trial (2019) found no substantial difference in HIV acquisition between DMPA-IM, the copper IUD, and the LNG implant. On this evidence, WHO MEC now classifies DMPA as Category 1 for women at high risk of HIV — it is no longer restricted on that basis. Dual protection with condoms is still advised.
Implant (etonogestrel — Implanon NXT / Nexplanon)
- A single subdermal rod giving 3 years of contraception; the most effective reversible method, acting by ovulation inhibition. Widely rolled out in the South African public sector. Irregular bleeding is the commonest reason for discontinuation and should be discussed up front. Efficacy is reduced by enzyme-inducing drugs (see below).
Intrauterine contraception
- Copper IUD (Cu-IUD) — non-hormonal, effective for 5–10 years depending on device; copper is toxic to sperm and creates a sterile inflammatory endometrium. It is also the most effective emergency contraceptive. Main drawback: heavier, more painful periods.
- Levonorgestrel intrauterine system (LNG-IUS) — releases progestogen locally, thinning the endometrium and thickening mucus; it reduces menstrual blood loss (first-line for heavy-menstrual-bleeding-management), provides endometrial protection (including as the progestogen arm of HRT), and has minimal systemic effects. Devices differ in dose and duration (e.g. 52 mg up to 8 years; lower-dose smaller devices for shorter durations / nulliparous women).
Barrier methods
- Male and female condoms are the only methods that protect against STIs and HIV — central to dual protection in the South African context — but have higher typical-use failure for pregnancy. The diaphragm (with spermicide) is an additional option.
Fertility awareness, LAM, and withdrawal
- Fertility-awareness methods track the fertile window; effectiveness depends heavily on training and consistency.
- Lactational amenorrhoea method (LAM) is ~98% effective only when all three conditions hold: fully/nearly fully breastfeeding, amenorrhoeic, and under 6 months postpartum.
- Withdrawal is better than nothing but unreliable.
Emergency contraception (EC)
- Copper IUD — the most effective EC, inserted up to 5 days after unprotected intercourse (or after the estimated ovulation), with the bonus of ongoing contraception.
- Ulipristal acetate 30 mg — a progesterone-receptor modulator, effective up to 120 hours; more effective than levonorgestrel, especially closer to ovulation. Do not give progestogen contraception for 5 days afterwards (it blunts ulipristal); offer a barrier in the interim.
- Levonorgestrel 1.5 mg — effective up to 72 hours, less effective with higher body weight; a progestogen method can be quick-started immediately.
Figure B4.2 — Emergency contraception clock showing copper IUD, ulipristal, and levonorgestrel timing with ongoing contraception rules.
Permanent methods
- Female sterilisation — tubal occlusion or, increasingly, salpingectomy (which also lowers ovarian-cancer risk), done laparoscopically or postpartum. Failure ~1 in 200; if it fails, the pregnancy is more likely to be ectopic. Counsel explicitly as permanent and largely irreversible.
- Vasectomy — simpler, safer, and more effective than female sterilisation, with a delay before it is effective (confirmed by post-procedure semen analysis); under-utilised.
Assessment — choosing the method
Shared decision-making
Start from the woman's goals (spacing vs completed family), then layer in eligibility and preference. LARC methods are encouraged first because of their effectiveness and cost-effectiveness, but the right method is the one she will use and is happy with.
Targeted history and examination
- Medical eligibility (WHO MEC 6th ed 2025 / SA 2019 guidelines / UKMEC) — VTE history, migraine with/without aura, blood pressure, smoking and age, BMI, current/past breast cancer, liver disease, SLE/antiphospholipid, ischaemic heart disease/stroke.
- Drug interactions — enzyme-inducing drugs (efavirenz, rifampicin/rifabutin, carbamazepine, phenytoin, some others) reduce the efficacy of CHC, POP, and the implant, but NOT the injectables, the Cu-IUD, or the LNG-IUS — so for a woman on efavirenz-based ART, steer toward an intrauterine method or the injectable rather than the implant or pill.
- STI/HIV risk — counsel dual protection; offer STI screening before IUD insertion and exclude pregnancy.
- Reproductive timeline — desire for future fertility (avoid permanent methods if uncertain; note DMPA's delayed return of fertility).
Figure B4.3 — Choice router linking patient goals, MEC red lights, enzyme-inducing drugs, and dual protection to safer method selection.
Special situations
- Postpartum and breastfeeding — timing and method depend on breastfeeding and VTE risk; see postpartum-contraception. CHC is MEC 4 if <6 weeks postpartum and breastfeeding.
- Post-abortion — contraception (including LARC) can be started immediately; see termination-of-pregnancy.
- Adolescents — LARC is safe and encouraged; counsel DMPA's reversible bone effect during peak-bone-mass years.
- Perimenopause — fertility persists; continue contraception until 12 months amenorrhoea if over 50, 24 months if under 50. HRT is not contraceptive (see climacteric-and-menopause).
- Women living with HIV — all methods are appropriate; integrate with dual protection and account for ARV enzyme-induction as above (hiv-counselling).
- Medical comorbidity — match the MEC category to the condition (cardiac disease, prior VTE, SLE, severe hypertension generally point away from CHC and toward progestogen-only or intrauterine methods).
Management — counselling and follow-up
- Lead with effectiveness tiers and offer LARC first, honestly framing typical-use failure.
- Quick-start an appropriate method when pregnancy is reasonably excluded, rather than waiting for the next period.
- Emphasise dual protection (a LARC plus condoms) given the South African HIV/STI burden.
- Pre-counsel bleeding changes (irregular bleeding/amenorrhoea on progestogen-only methods; heavier menses on Cu-IUD) — unanticipated bleeding is the leading cause of discontinuation.
- Arrange follow-up for technique, side effects, blood pressure (CHC), and satisfaction; make switching easy.
Red flags / pitfalls
- Prescribing CHC in migraine with aura, in smokers ≥35, or in uncontrolled hypertension — unacceptable stroke/VTE risk (MEC 4).
- Missing enzyme-inducer interactions — efavirenz/rifampicin reduce CHC, POP, and implant efficacy; recommend Cu-IUD, LNG-IUS, or injectable instead.
- Restricting DMPA on HIV-risk grounds — outdated; post-ECHO, DMPA is MEC Category 1 for women at high HIV risk.
- Mistaking DMPA's delayed return of fertility for infertility — counsel in advance.
- Giving progestogen within 5 days of ulipristal EC — reduces its efficacy.
- Forgetting dual protection — hormonal methods do not prevent STIs/HIV.
- Inserting an IUD without excluding pregnancy or screening for STI risk — perforation/expulsion and infection pitfalls.
- Counselling sterilisation as reversible — it is permanent, and a failure carries ectopic risk.
- Assuming HRT is contraceptive in the perimenopause — it is not.
- Ignoring adolescent bone considerations with DMPA — reversible, but counsel during peak-bone-mass years (osteoporosis).
Evidence anchors
- South African National Contraception Clinical Guidelines (2019) and the South African Handbook for Contraceptive Method Provision (2019), NDoH — the national standard, aligned to WHO MEC.
- WHO Medical Eligibility Criteria for Contraceptive Use, 6th edition (2025) — current MEC categories 1–4, including the post-ECHO DMPA classification.
- WHO Selected Practice Recommendations for Contraceptive Use — initiation, missed-pill, and switching guidance.
- FSRH (UK) — UKMEC (2016, amended 2019) and method-specific FSRH clinical guidance — cross-reference for CHC, POP, injectables, implant, intrauterine, and emergency contraception.
- ECHO trial (2019, Lancet) — no substantial difference in HIV acquisition between DMPA-IM, copper IUD, and LNG implant.
- South African EML / NDoH Standard Treatment Guidelines — method availability across public-sector levels.