Diminished ovarian reserve in female childhood cancer survivors with regular menstrual cycles and basal FSH <10 IU/I

BACKGROUND: Approximately 70% of children treated for cancer are cured, however the treatment often impairs reproductive function. The aim of the present study was to assess ovarian reserve in women with an apparently normal ovarian function, who were cured of cancer in childhood. METHODS: Twenty-one female survivors with regular menstrual cycles and basal FSH <10 IU/l were included. The control group included 21 healthy age-matched regularly cycling women. On cycle day 2-5, ovarian volume and number of small antral follicles (2-5 mm) were evaluated with transvaginal ultrasonography. Repeated sonography, urinary LH testing, and endocrine assessments were performed during the actual cycle. Cycle length was calculated. RESULTS: The female survivors had significantly smaller volume per ovary (4.9 versus 6.8 cm(3); P < 0.01), a lower number of small antral follicles per ovary (4.5 versus 8.0; P < 0.01), and lower total number of follicles per ovary (8 versus 11, P < 0.01). Hormonal profiles were similar, but the mean cycle length of the female survivors was significantly shorter than in the control group (28.3 versus 31.0 days; P < 0.05). CONCLUSIONS: Childhood cancer survivors with regular menstrual. cycles and basal FSH <10 IU/l seem to have a diminished ovarian reserve. Consequently, they may have a shortened reproductive span and an early menopause.