B cell translocation gene 2 expression levels in human granulosa cells is negatively associated with in vitro fertilization/intracytoplasmic sperm injection outcomes: a pilot study.

Purpose: This study aimed to monitor the expression of B-cell translocation gene 2 (BTG2) in granulosa cells of patients undergoing IVF/ICSI with respect blastocyst quality outcomes.

Methods: We recruited 181 women undergoing IVF/ICSI cycles for infertility. Granulosa cells were extracted from follicular fluid. BTG2 expression level of granulosa cells were stratified into tertiles (low, middle, and high), and the patients of each tertile were compared for outcome indicators by Kruskal-Wallis analysis. Spearman's correlation analyses were used to evaluate the correlation between BTG2 mRNA levels and outcome indicators. Generalized linear models and generalized additive models with smoothing splines were used to adjust for potential confounders.

Results: Patients in the low BTG2 tertile had higher oocyte retrieval, fertilization, blastocyst formation, and high-quality blastocyst rates than those in the high BTG2 tertile. Patients in the high BTG2 tertile exhibited a downward trend in implantation and clinical pregnancy rates compared to those in the low or middle BTG2 tertiles, whereas the early pregnancy loss rate showed an upward trend, although the difference was not significant. After adjusting for confounding factors, the expression level of BTG2 was negatively correlated with oocyte retrieval, blastocyst formation, and high-quality blastocyst rates. Stratified analysis of AMH > 4 ng/ml showed elevated BTG2 expression was associated with reduced oocyte retrieval, fertilization, cleavage, blastocyst formation, and high-quality blastocyst rates. No differences in these outcomes were observed in patients with AMH ≤ 4 ng/ml.

Conclusion: In women with high AMH levels (> 4 ng/ml) elevated BTG2 expression in granulosa cells was associated with poor quality blastocyst outcomes.