Intrauterine, Hormonal and Surgical Contraception

Intrauterine devices act locally

An intrauterine device (IUD) is a small device placed inside the uterus by a trained professional. Historical examples include the nonmedicated Lippes loop, copper-releasing devices such as CuT and Multiload 375, and progestin-releasing systems. Modern copper and hormonal IUDs are both highly effective long-acting reversible contraceptives. Neither is intended to remain in place indefinitely; safe placement, follow-up and removal depend on the device and clinical circumstances.

Copper ions interfere with sperm movement and function, making fertilisation less likely. Hormone-releasing IUDs release a progestin that thickens cervical mucus, creating a barrier to sperm movement, and changes the uterine lining; some users also have altered ovulation. Their main contraceptive action is to prevent fertilisation, not to terminate an implanted pregnancy. The source emphasises uterine changes, but it is important not to misrepresent implantation prevention as the routine primary mechanism.

Pills change reproductive physiology

Combined oral contraceptive pills contain oestrogen and a progestin. Their feedback effects on the hypothalamic–pituitary–ovarian axis suppress the gonadotropin surge needed for ovulation. Progestins also thicken cervical mucus and alter the endometrium. Progestin-only pills vary in how consistently they suppress ovulation, so exact actions and schedules depend on the formulation. Suppressing ovulation does not remove eggs from the ovaries or permanently stop gamete production.

One familiar combined-pill schedule has 21 active tablets followed by a seven-day break or inactive tablets; other packs use different schedules and must not be treated as interchangeable. The source names the nonsteroidal contraceptive Saheli, developed in Lucknow, which uses centchroman (ormeloxifene) and has a regimen different from ordinary daily steroid-containing pills. Its weekly maintenance schedule should not be confused with taking a single tablet once at the beginning of treatment.

Injectable contraception and implants

An injectable contraceptive delivers a long-acting hormonal preparation, while a subdermal implant releases progestin gradually from small rods or devices placed under the skin by a trained professional. Depending on formulation, these methods suppress ovulation, thicken cervical mucus and alter the endometrium. They reduce the need to remember a daily dose but may change bleeding patterns and have method-specific effects on the return of fertility after stopping.

Long-acting reversible methods differ fundamentally from sterilisation. A copper IUD or an implant can be removed; a vasectomy or tubal sterilisation is intended to be permanent. When comparing choices, distinguish efficacy against pregnancy from protection against sexually transmitted infections. Hormonal methods and IUDs do not provide the infection-barrier benefit of condoms.

Emergency contraception acts after unprotected intercourse

Emergency contraception aims to prevent pregnancy after unprotected sex or a recognised contraceptive failure. Oral emergency contraceptive pills, including levonorgestrel and ulipristal acetate, work principally by delaying or inhibiting ovulation before fertilisation. A copper IUD can also be used as emergency contraception and then retained for longer-term protection if appropriate. These options are not treatments for an established implanted pregnancy.

The source states a 72-hour interval, but evidence-based guidance permits some emergency contraceptive methods within five days (120 hours); the most suitable method and how effectiveness changes with time are method-specific. Earlier access is generally advantageous. For example, a copper IUD placed within the appropriate window is highly effective, whereas levonorgestrel pills work best when taken earlier. Medical advice should consider individual timing and eligibility.

Sterilisation blocks transport rather than gamete formation

In vasectomy, the vas deferens carrying sperm from the epididymis is divided or occluded. The testes continue to produce sperm and testosterone, but sperm no longer enter the ejaculate after successful clearance; other glands still contribute seminal fluid. Sterility is not immediate after the procedure, and follow-up testing is used clinically to confirm success. Sexual desire and erection are not expected to disappear merely because the duct was interrupted.

Tubal sterilisation blocks, seals or removes parts of the fallopian tubes, interrupting the route by which sperm and oocyte could meet. The ovaries remain in place, usually continue ovulation and continue hormone production. Both procedures are intended to be permanent; attempts at reversal may be difficult and may not succeed. Removal of the gonads would instead eliminate hormone-producing tissue and cause major endocrine consequences, so it is not equivalent to routine sterilisation.

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