Synergistic effect of growth hormone and gonadotropins in achieving conception in "clonidine-negative" patients with unexplained infertility.
Based on preliminary reports by others and by us of a potentiating effect of growth hormone (GH) on human menopausal gonadotropin (hMG)-induced ovulation, a study using a randomized, prospective, cross-over protocol between GH + hMG/human chorionic gonadotropin (hCG) and hMG/hCG was undertaken. The study included patients with long-standing (2-11 years) unexplained infertility with a negative or reduced GH response to clonidine (up to 150 micrograms of clonidine orally). The first cycle was randomly assigned between GH/hMG/hCG (study cycle) and hMG/hCG alone (control cycle), and after an interval cycle the patient's treatment was crossed over. All patients who completed the study had previously undergone 1-20 attempts at ovulation induction for in vitro fertilization (IVF) and 5-40 cycles of ovulation induction for in vivo fertilization at three different medical centers. Three patients conceived on the combined GH/hMG cycle, with diminution in the hMG consumption needed for ovulation induction in the study cycles. Another patient with long-standing mechanical infertility underwent 11 abortive attempts at ovulation induction with hMG for IVF but has never achieved egg retrieval. On the GH/hMG/hCG ovulation induction cycle, three mature ova were retrieved as opposed to no response and cancellation of the "hMG only" cycle. Another patient with 11 years of primary infertility who had undergone 21 previous attempts at ovulation induction and had reached follicular aspiration in only three of those cycles conceived spontaneously on the first cycle after the GH/hMG/hCG IVF/ET cycle. All four pregnancies that have been achieved by now in seven GH/hMG-treated patients ended in cesarean deliveries of four normal male neonates. No correlation was found between the follicular fluid levels of insulin-like growth factor I (IGF-I) and the fertilization rate in vitro. The peripheral IGF-I levels were significantly higher during the follicular phase of the study cycles than during the respective stage of the control cycles or the luteal phase of either cycle. A study of serum GH-binding protein (GH-BP) levels revealed gradual increases in the late follicular phase, in the luteal phase, and in early pregnancy. On the basis of this study and in keeping with earlier reports, we conclude that the addition of GH to hMG/hCG may serve as a contributory adjunct in selected patients. However, in contrast to others who could not find a correlation between the response to acute tests for GH release and the ovarian response to combined treatment, we conclude that the clonidine test can play a discriminatory role in identifying patients who may benefit from this innovative combination.