Major complications attributable to
oral contraceptives (OCs) may occur in the circulatory system. The inherent risk factors, such as race and family history, are unchangeable. Others may be altered by patient counseling and subsequent adjustment of certain behaviors.
Hypercoagulability is
estrogen dose related. Older, high-dose-
estrogen OC users were at 40% increased risk of mortality from thromboembolic phenomena. Reduction in
estrogen content has unmasked the androgenic effects of some
synthetic progestogens. These effects may include progression of
atherogenesis, effected through changes in
cholesterol and
lipoproteins; reduction in
sex hormone binding globulin (SHBG), which enhances the androgenic effect; and changes in carbohydrate metabolism. This review of clinical findings is based on four studies; three had prospective cohort designs, and one was a prospective randomized comparison of a
norgestimate-containing OC with a
norgestrel-containing one. Numbers of subjects ranged from 20 to 59,701; the largest evaluated 343,348 cycles of treatment. Study intervals were from 4 to 24 months. The findings reported here are from the individual studies. 1. The normal value for
cholesterol is less than 200 mg/dL. Of 2,197 women who met this cut-off point, 95% remained below it after 6 months of treatment. Of 756 who initially exceeded this value, 25% were below after 6 months and 75% remained above it. All studies to date have demonstrated that
norgestimate produces consistent and significant elevations in
high-density lipoprotein levels and variable change in
low-density lipoproteins. A similar effect was noted on serum
triglyceride values.(ABSTRACT TRUNCATED AT 250 WORDS)