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Obstetrics and Gynecology
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More Than Just Contraception
Oral contraceptive pills offer cancer protection, other health benefits
Oral contraceptive pills do more than just prevent pregnancy, but these other health benefits have for decades remained underrecorded and underappreciated. And these benefits are far-ranging, according to Prof. Unnop Jaisamrarn of Thailand's Chulalongkorn University, who was in Manila last year for the Philippine Obstetrical and Gynecological Society convention.
A renowned specialist in reproductive endocrinology, Prof. Jaisamrarn spoke on Emerging Concepts in Oral Contraceptive Health Benefits, in which he cited regulation of the menstrual cycle, reduction of cancer incidence, and prevention and treatment of certain diseases among the other health benefits that oral contraceptives offer.
Said Prof. Jaisamrarn: "They can counteract the adverse health effects of lifestyle changes in modern society. Health-care providers should not overlook these benefits in determining an individual's suitability for oral contraceptive pills."
In normal menstruating women, the follicular development during endometrial changes depends on the gonadotropins secreted from the pituitary gland. But in women who use contraceptives, the gonadotropin secretion is suppressed, thus there is no follicular development. Prof. Jaisamrarn said there is a low prevalence of iron deficiency in women using contraceptives as blood flow during menstruation is reduced by 50 percent. Studies have shown that hemoglobin and serum ferritin are increased among contraceptive users.
After ovulation, progesterone from the corpus luteum will stimulate the production of prostaglandin. Prostaglandin synthesized from the uterus in the luteal phase will make the myometrium contract and dysrhythmic, and will cause ischemia of the myometrium. The uterine activity, ischemic myometrium, and the sensitization of nerve terminals to prostaglandins will cause the woman to experience pain or dysmenorrhea. Contraceptives help prevent and treat this by suppressing ovulation.
Although contraceptives cannot ease all symptoms of premenstrual syndrome completely, Prof. Jaisamrarn said five out of six randomized controlled trials proved it to be effective in the relief of specific symptoms.
Cancer Prevention
Prof. Jaisamrarn presented several studies confirming a 40-percent reduction in the relative risk for ovarian cancer among contraceptive users. The reduction was increased by longer use of contraceptives and persisted long after discontinuation. Both high-dose and low-dose pill users get this protection. It was noted that women with positive breast cancer gene, BRCA-1 and BRCA-2, who have a higher risk for ovarian cancer and took low-dose contraceptive reduced the relative risk for ovarian cancer by 50 percent.
Several cohort studies have also shown reduction of risks for endometrial cancer. The risk was 0.4 for four years contraceptive intake, 0.3 for eight years and 0.28 for 12 years. Prof. Jaisamrarn said the progestogen component is primarily responsible for the anticancer effect of contraceptives.
Prof. Jaisamrarn said other noncontraceptive benefits have been found for pelvic inflammatory diseases where the relative risk was at 0.3 to 0.9. Benign breast diseases such as fibroadenoma and fibrocystic disease were prevented by high-dose contraceptive use.
Contraceptives, even at low dose with 20 micrograms of ethinyl estradiol (EE), also give protection against and treatment for endometriosis. In the case of their effect on uterine fibroids, studies have shown conflicting results. Some have even shown an increased risk of uterine fibroids. However, no randomized trial has yet been done.
While no metaanalysis has been done, nine out of 14 case control studies showed positive results on the effect of contraceptives on rheumatoid arthritis. Contraceptives also have a positive effect on the quality of bone, causing up to 12 percent increase in bone mass density. This protective mechanism against osteoporosis is attributed primarily to the effect of estrogen, although progestin may also be important. He also noted that among menopausal women, both HRT and contraceptive increased the bone mass density in the lumbar spine and in the hip area.
Low-dose contraceptive also helps control acne. Prof. Jaisamrarn said contraceptives reduce the ovarian and adrenal androgen secretion, increasing the sex hormone body globulins and reducing 5-alpha-reductase activity, all leading to a reduction of free testosterone, which is a major factor causing acne.
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