Dual-trigger improves oocyte maturation in patients with low oocyte maturation rate: a self-control study

Abstract Background For patients with low maturation rate, the efficacy of dual-trigger is still uncertain with few related data available. This large retrospective study focused on the effect of dual-trigger in oocyte maturation in patients with a history of low oocyte maturation rate. Methods A large retrospective self-controlled study was performed, which included 199 patients with a high proportion of immature oocyte (> 50%) in a previous hCG-only trigger cycle receiving a subsequent dual-trigger between January 2014 and June 2022. The primary outcome was the oocyte maturation rate, and the secondary outcomes were the number of oocytes retrieved, the normal fertilization rate, the high-quality embryos rate and the blastocyst formation rate. Linear regression analysis was applied to control the potential confounders. Results The results showed that no significant difference was observed in the number of follicles of > 14 mm and the E2 level on trigger day between the hCG-only and the dual-trigger cycle. Although the number of oocyte retrieval was comparable, higher rates of the oocyte maturation (64.96% vs. 39.40%), P < 0.001) and the normal fertilization (70.47% vs. 62.89%, P = 0.006) were associated with the dual-trigger group. In addition, a slightly higher rate of high-quality embryos (51.21% vs. 50.53%) and blastocyst formation (46.18% vs. 30%) were also observed in the dual-trigger group, although difference didn’t reach statistical significance. Furthermore, linear mixed model confirmed that the dual-trigger was positively associated with the oocyte maturation rate (β = 0.294, P < 0.001) after adjusting potential confounders, such as ovarian stimulation protocols. Conclusions Co-administration of GnRH-a and hCG for final oocyte maturation was suggested as an effective tool to improve oocyte maturation in patients with low maturation rate.