ADJUNCTIVE GROWTH-HORMONE DURING OVARIAN HYPERSTIMULATION INCREASES LEVELS OF INSULIN-LIKE GROWTH-FACTOR BINDING-PROTEINS IN FOLLICULAR-FLUID - A RANDOMIZED, PLACEBO-CONTROLLED, CROSS-OVER STUDY

GH increases circulating insulin-like growth factor I(IGF-I), which ca n promote the growth and differentiated function of ovarian granulosa and theca cells. Reported studies of GH as an adjunct to menotropin st imulation in women, largely those with ovarian dysfunction, have not c onsistently shown a benefit of GH, despite increases in serum and foll icular fluid IGF-I. We hypothesized that changes in intrafollicular IG F-binding proteins (IGFBPs), which can antagonize IGF actions on granu losa cells, may underlie the inconsistent effects of GH. In the presen t study of GH, administered in double-blind, placebo-controlled, cross -over fashion to regularly cycling women undergoing in vitro fertiliza tion, we found that follicular fluid levels of IGFBP-1, -3, and -4 and serum levels of IGFBP-3, as well as follicular fluid and serum IGF I, were significantly increased in the GH-treated cycles, when compared with the placebo cycle of the same patient. We suggest that the net in crease in intrafollicular IGFBPs in GH cycles may mitigate the potenti al beneficial effect of increased IGF-I.