Urinary hormonal profile during the first cycle of low-dose oral contraceptive pills in women

Ovarian function was studied in ten normal fertile women before and during the first cycle on a low-dose micropill containing 30 mcg ethinyl estradiol and 150 mcg L-norgestrel. In a control cycle and the first treatment cycle, steroid metabolites estrone-3-glucuronide (E1-3G) and pregnanediol-3 alpha-glucuronide (Pd-3G) were measured in daily early morning urine (EMU) samples. Also, luteinizing hormone (LH) was estimated during the expected periovulatory period. During the first cycle of micropill intake, ovarian function was suppressed in all cases. This is evidenced by significantly lower E1-3G and Pd-3G and absent midcycle LH peak compared to control cycles. The pattern of steroid metabolites was almost flat with no peaks. It is concluded that there is no need to cover the first cycle of micropill intake with other contraceptive methods.