New progestogens in oral contraceptives

The aim of using new synthetic progestogens (gestodene and norgestimate) in oral hormonal contraceptives is to find a combination that has a more beneficial effect on metabolism and endometrium than presently available formulations. Our studies with low-dose pills containing 30 micrograms ethinyl estradiol/150 micrograms levonorgestrel or 30 micrograms ethinyl estradiol/150 micrograms desogestrel compared with the new pills with 35 micrograms ethinyl estradiol/250 micrograms norgestimate or 30 micrograms ethinyl estradiol/75 micrograms gestodene revealed no significant alterations of serum glucose after glucose loading. With all four combination pills, insulin levels were slightly elevated when compared with controls. Studies of the lipid metabolism showed that depending on the type and estrogen combination, progestogens have different effects on lipid metabolism. The new progestogens seem to have a more pronounced effect on triglycerides, whereas total cholesterol and high-density lipoprotein cholesterol remain almost unchanged. In general, it could be shown that low-dose oral contraceptives have little impact on lipid metabolism. Studies with low-dose monophasic preparations, including the new formulations, reveal only a low effect on blood coagulation. According to our and other data on the new progestogens in oral contraceptives available so far, it can be expected that such low-dose monophasic and triphasic combination pills will be beneficial during longtime use with respect to side effects on the cardiovascular system and control of the menstrual cycle.