Auditory brainstem response in premenopausal women taking oral contraceptives

The aim of this prospective study was to evaluate the effects of the new monophasic oral contraceptiveson the audiological system in premenopausal women. METHODS: The auditory brainstem response (ABR)was measured in 94 women during the follicular, periovular and luteal phases of one menstrual cycle in which ovulationwas con®rmed using sonography and serum progesterone concentration. The latencies for waves I, III and Vwere determined, and the inter-peak intervals were calculated for waves I±III, I±V and III±V. All 94 women begantaking oral contraceptives: 23 women used 20 mg ethinyl estradiol (EE) plus 150 mg desogestrel, 24 women used 30mg EE plus 75 mg gestodene, and 47 women used 15 mg EE plus 60 mg gestodene. During the third month of contraceptive intake, each subject was again tested for ABR, as above. RESULTS: The wave latencies and inter-peakintervals showed shorter values during the periovular phase with respect to the luteal phase (P < 0.05), the follicularphase for wave I and for inter-peak interval I±V (P < 0.05) of the menstrual cycle. All of the ABR results in pillusers were statistically different from those of the periovular phase (P < 0.05), though similar to those of both theluteal and follicular phases (P = NS). CONCLUSIONS: ABR seems to depend on the variations of ovarian steroidsduring the menstrual cycle and during oral contraceptive intake.