Low-dose growth hormone-releasing factor may enhance folliculogenesis in regularly menstruating women: a preliminary study

Objective To evaluate the effect of low-dose GH-releasing factor (GRF) on folliculogenesis in regularly menstruating women. Design Prospective clinical trial where individual patients served as their own control. Setting Outpatient Reproductive Endocrine/Infertility Clinic of the Los Angeles County-University of Southern California Medical Center, Los Angeles, California. Patients Seven regularly menstruating women. Intervention During treatment cycles, subjects received 100 μ g SC GRF on cycle days 2 to 11 and were observed during a control cycle. Main Outcome Measures Follicle number and diameter, as well as endometrial thickness were all assessed by vaginal ultrasound and blood was obtained for serum FSH, LH, E 2 , P, GH, insulinlike growth factor 1 (IGF-1), and insulin-like growth factor binding protein-3. Results During cycles treated with GRF, GH, and IGF-1 levels were normal. However, follicular growth rates and E 2 to FSH ratios were significantly higher. The day of the peak E 2 to follicular diameter ratio after GRF was earlier than in control cycles. Endometrial growth rates were also greater with GRF. Conclusions Our data, although preliminary, support the hypothesis that low doses of GRF may independently stimulate the ovary and enhance folliculogenesis.