Efficacy of ER-alpha Polymorphisms and the Intrafollicular IGF System for Predicting Pregnancy in IVF-ET Patients

Aims: To evaluate the efficacies of the estrogen receptor-alpha (ER-alpha) gene polymorphisms and of the intrafollicular insulin-like growth factor(IGF) system for predicting pregnancy in in vitro fertilization and embryo transfer(IVF-ET) patients. Methods: A total of 96 patients undergoing IVF-ET were included in this study. Genotyping for the ER-alpha gene PvuII and XbaI polymorphisms was performed using polymerasechain reaction and single base extension method. Follicular fluid(FF) IGF-I, IGF-II, and IGFBP-3 concentrations were measured by RIA, and IGFBP-4 by ELISA. We compared, between pregnant(n = 28) and non-pregnant groups(n = 68), the allele frequency, genotype distribution and haplotype distribution of Pvu II and Xba I polymorphisms, and then FF IGF-I, IGF-II, IGFBP-3, IGFBP-4 concentrations and their ratios. Results: No significant differences were found between the two groups in terms of allele, genotype or haplotype distributions of the ER-alpha gene PvuII and XbaI polymorphisms between the two groups. The mean FF IGF-I/IGFBP-3 ratio was significantly higher in the pregnant group(5.9 +/- 8 1.5 vs. 4.8 +/- 1.5 x 10(-2)). Conclusions: The intrafollicular IGF-I/IGFBP-3 ratio of the FF of the dominant follicle during oocyte retrieval appears to be related to the establishment of pregnancy in IVF-ET patients, whereas the ER-alpha gene PvuII and XbaI polymorphisms do not. Copyright (C) 2008 S. Karger AG, Basel