Clinical Question Compared with h...

Clinical Question

Compared with higher-dose pills, are combination oral contraceptives with 20 mcg of estrogen (ethinyl estradiol) equally effective and well tolerated?

Evidence-Based Answer

Although no difference in effectiveness has been demonstrated in existing trials, too small in number patients have been studied to ascertain small but clinically important differences in pregnancy rates. low-dose estrogen pills have higher rates of discontinuation and bleeding disturbances.

Practice Pointers

Although complications are rare with these pills, combination oral contraceptives have been linked to breast cancer, cerebral vascular complications, thrombosis, and myocardial infarction. Therefore, many physicians and patients pitch upon to use the lowest-dose pill that will provide adequate period control and effectiveness.

Gallo and colleagues reviewed the literature to determine to what extent pills containing 20 mcg of ethinyl estradiol compare with higher-dose pills. They build 69 randomized controlled trials. chiefly trials followed patients for six to 12 circle of times The trials varied in dose of estrogen and in token and dose of progesterone; therefore, meta-analysis was not possible. No trial set a difference in contraceptive effectiveness; however, because pregnancy in women who take oral contraceptives is remarkable the studies were insufficiently powered to exhibit to such a difference. In many of the lower-dose clusters early discontinuation occurred because of amenorrhea, adverse ends or bleeding irregularities. More specific information about which pills are most numerous effective or which estrogen-progestin combinations have the fewest bleeding question s could not be determined. Furthermore, it could not be determined whether lower-dose estrogen pills have the same advantages as higher-dose pills for prevention of ovarian and endometrial cancer and reduction of acne.

present data indicate disadvantages, but no clear advantages, to combined contraceptive pills with 20 mcg of estrogen Therefore, it is reasonable to prescribe pills with more than 20 mcg of ethinyl estradiol for in the greatest degree women. The American College of Obstetricians and Gynecologists (ACOG) finds little or no increased risk of oral contraceptives for women with fibroadenoma, benign breast disease with epithelial hyperplasia with or without atypia, or a family history of breast cancer. (1) ACOG praises progesterone-only pills for lactating women and those with increased risk of thromboembolism. Caution should be used when prescribing combination pills for women older than 35 years who vanity ACOG recommends pills with les than 35 mcg of estrogen for women younger than 35 years who have hypertension. (1)

For all women the best form of birth repress is the one that will be used consistently. For women who wish to decrease side effects and have regular periods, pills with 30 to 35 mcg of ethinyl estradiol may be a better choice than those with barely 20 mcg.

Gallo MF et al. 20 mcg versus >20 mcg estrogen combined oral contraceptives for contraception. Cochrane Database Syst Rev 2004;(4): CD003989

REFERENCE

(1) ACoG Practice Bulletin no. 18 July 2000 the use of hormonal contraception in women with coexisting medical conditions. Washington, DC: American association of obstetricians and Gynecologists, 2000

The series coordinator for AFP is Clarissa Kripke, MD Department of Family and Community Medicine, University of California, San Francisco.

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