Contraception

Contraception can interrupt this sequence in different places: it may stop an egg maturing or being released, prevent sperm reaching the egg, or prevent implantation. Hormonal methods use hormones to alter reproductive processes; non-hormonal methods do not.

Contraception prevents pregnancy. To evaluate a contraceptive method, we must weigh its benefits against its limitations and risks, then reach a reasoned conclusion. Effectiveness matters, but it is not the only consideration: protection from sexually transmitted infections (STIs), possible side effects, ease of correct use, duration of action and whether the method is reversible may all affect a decision.

Contraception reduces the chance of pregnancy. Pregnancy requires several events, including the maturation and release of an egg, sperm reaching that egg and the resulting embryo becoming established in the uterus. A contraceptive method lowers the chance of pregnancy by disrupting one or more of these events.

Contraception means deliberately preventing pregnancy. Different methods interrupt reproduction at different stages: they may prevent ovulation, stop sperm reaching an egg or make fertilisation very unlikely. This means that methods cannot be compared only by asking whether they are “hormonal” or “non-hormonal”; their mechanism, reliability, risks and suitability also matter.