[Impact of trigger timing of gonadotropin-releasing hormone antagonist regimen for infertility patients of various ages].

Objective: To investigate the impact of trigger timing of gonadotropin- releasing hormone (GnRH) antagonist regimen for infertility patients of various ages. Methods: This was a retrospective study, 1 529 infertility patients who receiving GnRH antagonist regimen in Chongqing Health Center for Women and Children from January 2017 to December 2018 were divided into the advance trigger group and the standard trigger group, and further divided into three subgroups according to age:<35 years, 35-40 years,>40 years. The number of retrieved oocytes and transplantable embryos, the clinical pregnancy rate and the live birth rate among patients in the advance trigger group and standard trigger group in various age subgroups were compared. Results: (1) The gonadotropin (Gn) days among the three age subgroups were significantly shorter in the advance trigger group compared to the same-aged standard trigger group (all P<0.01), but only in the 35－40 years and >40 years subgroups, the Gn doses in the advance trigger group [(2 702±551) and (2 780±561) U] were significantly less than those in the standard trigger group (all P<0.01). In the <35 years subgroup, the number of oocytes retrieved and transplantable embryos of the advance trigger group (6.6±4.8 and 2.6±2.7) were significantly less than those of the standard trigger group (all P<0.01), but there was no difference in the number of top-quality embryos (P=0.580); however, in the 35－40 years and >40 years subgroups, there were no significant differences between advance and standard trigger groups in terms of the afore mentioned 3 indicators (all P>0.05), only the numbers of top-quality embryos in the advance trigger group (0.6±1.0 and 0.6±0.9) were significantly higher than those in the standard trigger group (all P<0.01). (2) In the <35 years and 35－40 years subgroups, no significant differences were noted between the advance trigger group and standard trigger group with regard to the clinical pregnancy rate and live birth rate (all P>0.05); but in the >40 years subgroup, the clinical pregnancy rate of the advance trigger group was significantly higher than that of the standard trigger group [33.0% (30/91) vs 19.2% (25/130), P=0.020], and there was no statistical difference in the live birth rate (P=0.064). (3) Multivariate logistic regression analysis showed that trigger timing was an independent predictor of clinical pregnancy rate in the >40 years subgroup (OR=0.334, 95%CI: 0.119-0.937, P=0.037), but not an independent predictor of live birth rate (P>0.05). Conclusions: Advance trigger in the GnRH antagonist protocol for infertility patients >40 years old could effectively reduce Gn times and Gn dosage, increase the number of top-quality embryos, and improve the clinical pregnancy rate. Therefore, compared with patients ≤40 years of age, patients >40 years might benefit more from advance trigger.