A prospective study evidencing rhinomanometric and olfactometric outcomes in women taking oral contraceptives

BACKGROUND: The aim of this prospective study was to evaluate the changes i n olfactory sensitivity of oral contraceptive (pill) users. METHODS: Sixty women underwent rhinomanometric and olfactometric determinations during the follicular, periovular and luteal phases of the menstrual cycle, and at da y 7, 14 and 21 of contraceptive intake. Thirty-one women used 30 mug ethiny l oestradiol plus 75 mug gestodene and 29 women used 20 mug ethinyl oestrad iol plus 150 mug desogestrel. RESULTS: Rhinomanometry showed higher but not statistically significant values during the periovular phase than in the f ollicular and luteal phases. Olfactometry showed a higher sensitivity durin g the follicular and periovular phases than during the luteal phase of the menstrual cycle. The rhinomanometric surveys in pill users were statistical ly different from those of the luteal phase (P < 0.02) and the follicular a nd periovular phases (P < 0.001). The olfactometric thresholds during the p eriod of contraceptive use were statistically different from those of the f ollicular phase for a few odorous substances, and from those of the periovu lar phase for each odorous substance, but similar to those of the luteal ph ase (P = NS). CONCLUSIONS: Unlike the rhinomanometric airflow and trans-nas al pressure, the olfactory threshold to odours seems to depend on the varia tions of the ovarian steroids during the menstrual cycle and on the iatroge nic effects of oral contraceptives.