Question
Classify contraceptive methods into barrier, hormonal, IUD, and surgical categories. Give examples of each. Which methods are reversible and which are permanent?
(NCERT Class 12 — directly asked in CBSE boards and NEET)
Solution — Step by Step
| Method | How it works | Reversible? |
|---|---|---|
| Male condom | Covers penis, prevents sperm from entering vagina | Yes |
| Female condom (Femidom) | Lines vagina, blocks sperm | Yes |
| Diaphragm | Covers cervix, blocks sperm entry into uterus | Yes |
| Cervical cap | Smaller cap over cervix | Yes |
Barrier methods also protect against STIs (condoms specifically). No hormonal side effects.
| Method | How it works |
|---|---|
| Oral contraceptive pills (OCPs) | Contain synthetic estrogen + progesterone; prevent ovulation, thicken cervical mucus |
| Saheli | Non-steroidal pill (centchroman); developed in India by CDRI, Lucknow; taken once a week |
| Injectable contraceptives | Depo-Provera (medroxyprogesterone); one injection every 3 months |
| Implants | Norplant; placed under skin of upper arm; effective for 5 years |
All hormonal methods are reversible — fertility returns after stopping.
| Type | Example | Mechanism |
|---|---|---|
| Non-medicated (inert) | Lippes loop | Increases phagocytosis of sperm in uterus |
| Copper-releasing | CuT, Cu7, Multiload 375 | Cu²⁺ ions are toxic to sperm; also prevents implantation |
| Hormone-releasing | LNG-20 (Mirena), Progestasert | Release progesterone; thicken cervical mucus, make uterus unsuitable for implantation |
All IUDs are reversible — removed by a doctor when pregnancy is desired.
| Method | Gender | Procedure |
|---|---|---|
| Vasectomy | Male | Cut and tie the vas deferens; sperm can’t reach semen |
| Tubectomy | Female | Cut and tie the fallopian tubes; egg can’t reach uterus |
These are considered permanent (irreversible in most cases). Microsurgical reversal is possible but success rates vary.
Why This Works
Each contraceptive method targets a different step in the reproductive process. Barrier methods prevent sperm from reaching the egg. Hormonal methods prevent the egg from being released. IUDs create an inhospitable uterine environment. Surgical methods permanently block the transport route for gametes.
The ideal contraceptive doesn’t exist — each has trade-offs between effectiveness, reversibility, side effects, and protection against STIs. That’s why family planning counselling considers individual needs.
Alternative Method — Effectiveness Ranking
For NEET, know the effectiveness ranking (most to least effective):
- Surgical (vasectomy/tubectomy) — > 99%
- Hormonal (pills, implants, injectables) — ~95-99%
- IUDs — ~95-99%
- Barrier (condoms) — ~85-95% (with typical use)
- Natural methods (rhythm, withdrawal) — ~75-85%
NEET loves to ask: “Which is the most effective reversible contraceptive?” Answer: hormonal implants or hormone-releasing IUDs.
Common Mistake
Students often say “IUDs prevent fertilisation.” Most IUDs primarily work after fertilisation — they prevent implantation of the fertilised egg or make the uterine environment hostile. Copper IUDs also have a spermicidal effect. For NEET, be specific about the mechanism — don’t just say “prevents pregnancy.” Also, Saheli is NOT a hormonal pill in the traditional sense — it’s non-steroidal (centchroman is a SERM, selective estrogen receptor modulator). Writing it as “hormonal” is technically incorrect.