IVF performance of women who have fluctuating early follicular FSH levels.

ObjectivesThe aim was to evaluate whether women who have early follicular follicle-stimulating hormone (FSH) levels > 12 mIU/ml have reduced response to follicular stimulation for in vitro fertilization (IVF) in a following month, in spite of normal FSH levels.Material and methodsIn a 3-year period from January 1996 to December 1998, 303 women aged 38 years and above and/or who had previously responded poorly to superovulation for IVF gave blood samples for FSH, luteinizing hormone (LH), and estradiol (E2) on day 2 of menstruation before commencing treatment.ResultsIn 117 (38.6%) of these women, FSH levels were > 12 mIU/ml (range 12-114 mIU/ml). Sixty-six of these women gave a further 130 blood samples for FSH measurement in the following months. Seventy-eight (60.0%) of the tests showed raised FSH value > 12 mIU/ml. Thirty women whose repeat FSH levels were < 12 mIU/ml underwent 41 IVF cycles (group 1). Sixty-three other women, older than 38 and/or who had a poor response to superovulation previously and whose FSH levels were < 12 mIU/ml, served as the control group (group II). There were no differences in the responses to superovulation and delivery rates between the two groups (14.6% vs. 12.7%).ConclusionsWomen whose early follicular phase FSH levels were raised > 12 mIU/ml had an increased risk (> 50%) that in subsequent cycles levels would remain raised, and it was not possible to predict which individuals would have favorable FSH levels. If the cycle day 2 FSH level returns to a "normal" level of < 12 mIU/ml, women aged 40 and above had substantial cycle cancellation rates (43%), but patients who achieved the stage of embryo transfer had a good chance of conceiving, regardless of their age.