Sequential use of letrozole and gonadotrophin in women with poor ovarian reserve: a randomized controlled trial

Sequential use of letrozole and human menopausal gonadotrophin (HMG) was compared with HMG only in poor ovarian responders undergoing IVF. Patients (n=53) with less than four oocytes retrieved in previous IVF cycles or less than five antral follicles were randomized to either letrozole for 5days followed by HMG or HMG alone. The letrozole group had lower dosage of HMG (P<0.001), shorter duration of HMG (P<0.001) and fewer oocytes (P=0.001) when compared with controls. Live-birth rate was comparable with a lower miscarriage rate in the letrozole group (P=0.038). Serum FSH concentrations were comparable in both groups except on day 8, while oestradiol concentrations were all lower in the letrozole group from day 4 (all P<0.001). Follicular fluid concentrations of testosterone, androstenedione, FSH and anti-Müllerian hormone were higher in the letrozole group (P=0.009, P=0.001, P=0.046 and P=0.034, respectively). Compared with HMG alone, sequential use of letrozole and HMG in poor responders resulted in significantly lower total dosage and shorter duration of HMG, a comparable live-birth rate, a significantly lower miscarriage rate and a more favourable hormonal environment of follicular fluid. The management of poor ovarian responders or women with poor ovarian reserve in IVF is controversial. The use of letrozole has been studied; however, results are inconsistent. This randomized trial studied the sequential use of letrozole and gonadotrophin compared with gonadotrophin alone in poor responders undergoing IVF. The sequential use of letrozole and gonadotrophin led to a significantly lower dosage and shorter duration of gonadotrophin use, significantly fewer oocytes, comparable live-birth rate, a significantly lower miscarriage rate and a more favourable hormonal environment at a lower cost.