Prediction, assessment, and management of suboptimal GnRH agonist trigger: a systematic review

Purpose: This systematic review aimed to identify baseline patient demographic and controlled ovarian stimulation characteristics associated with a suboptimal response to GnRHa triggering, and available options for prevention and management of suboptimal response. Methods: PubMed, Google Scholar, Medline, and the Cochrane Library were searched for keywords related to GnRHa triggering, and peer-reviewed articles from January 2000 to September 2021 included. Results: Thirty-seven studies were included in the review. A suboptimal response to GnRHa triggering was more likely following long-term or recent oral contraceptive use and with a low or high body mass index. Low basal serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol serum levels were correlated with suboptimal oocyte yield, as was a low serum LH level on the day of triggering. A prolonged stimulation period and increased gonadotropin requirements were correlated with suboptimal response to triggering. Post-trigger LH < 15 IU/L best correlated with an increased risk for empty follicle syndrome and a lower oocyte retrieval rate. Retriggering with hCG may be considered in patients with suboptimal response according to post-trigger LH, as in cases of failed aspiration. Conclusion: Pre-treatment assessment of patient characteristics, with pre- and post-triggering assessment of clinical and endocrine cycle characteristics, may identify cases at risk for suboptimal response to GnRHa triggering and optimize its utilization.