Contraception

The control of fertility to prevent pregnancy. Methods prevent ovulation in the woman, stop sperm from meeting an ovum in the fallopian tube (preventing fertilization), or prevent a fertilized ovum implanting in the uterus. Methods of contraception include total or periodic abstinence from sexual intercourse (see contraception, natural methods of); barrier methods (see contraception, barrier methods of); coitus interruptus; hormonal methods, including the use of oral contraceptives, implants, and injections (see contraceptives, injectable); intrauterine devices (see IUDs); postcoital methods (see contraception, emergency); or sterilization of the male (see vasectomy) or female (see sterilization, female).