Does Insulin-Like Growth Factor-I Level Associate with Pregnancy Outcomes in Primary and Secondary Infertile Women Undergoing In Vitro Fertilization? A Prospective Cohort Study

Background: Infertility, which affects 8%–12% of couples worldwide and 21.9% of couples in Pakistan in particular, is a major reproductive health issue. In vitro fertilization (IVF) has emerged as a prevalent therapeutic intervention. Recent studies have identified insulin-like growth factor-I (IGF-I) as a promising biomarker for assessing embryo viability and predicting implantation outcomes in IVF procedures. Objective: To evaluate the relationship between IGF-I levels and IVF outcomes in women with primary and secondary infertility. Materials and methods: This prospective cohort study included 133 infertile women (99 with primary infertility and 34 with secondary infertility) aged 20-45 years. IGF-I levels were measured using an ELISA kit. Participants were grouped based on infertility type and cause of infertility. Statistical analyses included the Mann-Whitney U test, Pearson chi-square test, Kruskal-Wallis test, and Pearson correlation coefficient. Results: Women with secondary infertility had significantly higher IGF-I levels compared to those with primary infertility (279.40±85.89 ng/ml vs. 239.11±74.55 ng/ml, p=0.02). Male factors were the predominant cause of infertility in both groups. Patients with male-factor infertility had the highest IGF-I levels (267.1±77.6 ng/ml). Significant positive correlations were found between IGF-I levels and the number of oocytes fertilized (r=0.398, p<0.01), oocytes retrieved (r=0.326, p<0.01), oocytes at metaphase II (r=0.386, p<0.01), and cleaved embryos (r=0.369, p<0.01). Conclusion: This study demonstrates a positive correlation between IGF-I levels and various IVF outcomes. Higher IGF-I levels were associated with improved oocyte retrieval, fertilization, and embryo development.