Name four methods of contraception and state the principle of each.

Barrier methods such as condoms prevent the sperm from meeting the ovum. Intrauterine devices prevent implantation and, in some forms, also affect sperm motility. Oral contraceptive pills use hormones to prevent ovulation. Surgical methods, vasectomy and tubectomy, block the vas deferens or the fallopian tubes.

No citable source has been recorded for this record. Treat it as practice material, not as fact.

Explanation

The choice depends on whether the contraception is meant to be temporary or permanent.