Methods of contraception

INTRODUCTION
The available methods of contraception may be classified in many ways. For the sake of this discussion, traditional or folk methods are coitus interruptus, postcoital douche, lactational amenorrhea, and periodic abstinence (rhythm or natural family planning). Barrier methods include condoms (male and female), diaphragm, cervical cap, vaginal sponge, and spermicides. Hormonal methods encompass oral contraceptives and injectable or implantable long-acting progestins. In addition, the intrauterine contraceptive device (IUD) and sterilization (tubal ligation or vasectomy) are also part of the contraceptive armamentarium.

COITUS INTERRUPTUS
One of the oldest contraceptive methods is withdrawal of the penis before ejaculation. This results in deposition of the semen outside the female genital tract. It has the disadvantage of demanding sufficient self-control by the man so that withdrawal can precede ejaculation. Although the failure rate is probably higher than that of most methods, reliable statistics are not available. Failure may result from escape of semen before orgasm or the deposition of semen on the external female genitalia near the vagina.

POSTCOITAL DOUCHE
Plain water, vinegar, and a number of “feminine hygiene” products are widely used as postcoital douches. Theoretically, the douche serves to flush the semen out of the vagina, and the additives to the water may possess some spermicidal properties. Nevertheless, sperm have been found within the cervical mucus within 90 seconds after ejaculation. Hence, the method is ineffective and unreliable.

LACTATIONAL AMENORRHEA
The lactational amenorrhea method (LAM) can be a highly efficient method for breastfeeding women to utilize physiology to space births. Suckling results in a reduction in the release of gonadotropin releasing hormone, luteinizing hormone, and follicle-stimulating hormone. Beta-endorphins induced by suckling also induce a decline in the secretion of dopamine, which normally suppresses the release of prolactin. This results in a condition of amenorrhea and anovulation. During the first 6 months, if breastfeeding is exclusive, menses are mostly anovulatory and fertility remains low. A recent WHO Study on LAM revealed that during the first 6 months of nursing, cumulative pregnancy rates ranged from 0.9 to 1.2 percent. However, at 12 months, pregnancy rates rose as high as 7.4 percent. When using lactation as a method of birth control, the mother must provide breastfeeding as the only form of infant nutrition. Supplemental feedings may alter both the pattern of lactation and the intensity of infant suckling, which secondarily may affect suppression of ovulation. Second, amenorrhea must be maintained. Finally, the method should be practiced as the only form of birth control for a maximum of 6 months after birth.

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Revision date: July 3, 2011
Last revised: by Janet A. Staessen, MD, PhD