Growth hormone for in vitro fertilization

Abstract

Ovulation induction protocols for in vitro fertilization (IVF) are constantly under review and revision in an attempt to decrease gonadotropin requirements while improving follicular recruitment and pregnancy rate. Most studies of the effect of Growth Hormone on ovulation induction have investigated normally ovulating infertile women. Attention has begun to turn to its effect on women who fail to produce an optimal number of follicles in response to ovulation induction. To assess the effectiveness of growth hormone adjuvant therapy for women undergoing ovulation induction prior to IVF in two patient groups: a) those with no previous history of poor response and b) those with a history of poor response. This review has drawn on the search strategy developed for the Subfertility Group as a whole. Relevant trials were identified in the Group's Specialised Register of Controlled Trials. See Review Group details for more information. All RCTs were included if they addressed the research question posed and provided outcome data for intervention and control subjects. Outcomes of interest included pregnancy, oocyte/embryo number and peak estradiol level. A diverse search strategy was employed, including hand-search of 43 core journals from 1966 to the present, bibliographies of relevant trials, MEDLINE database, abstracts from North American and European meetings and contact with authors of relevant papers. Relevant data were extracted independently by two reviewers using the standardized data extraction sheet. Validity was assessed in terms of method of randomization, completeness of follow-up, presence or absence of crossover and co-intervention. 2x2 tables were generated for all relevant outcomes. Odds ratios were generated using the Peto modified Mantel-Haenszel technique. Statistical heterogeneity was assessed using x2. In women with no previous history of poor stimulation, the common odds ratio for pregnancy per cycle was 0.97 (95% CI 0.34-2. 76) Total dose of gonadotropin and number of oocytes retrieved were similar between treated and placebo groups. In previous poor responders, the common odds ratio for pregnancy per cycle instituted was 2.55 (95% CI 0.64-10.12). Again, no statistically significant difference was noted in gonadotropin dosage or oocyte number obtained, when all studies were considered. Data from 6 small trials suggest that in women with no previous poor response, GH augmentation does not improve the rate of pregnancy. In poor responders, a trend towards improved outcome with GH treatment deserves further study.