Effect of the co-administration of HCG and GnRH agonist (dual trigger) versus standard HCG trigger on morphokinetic embryo parameters

Research question: Does dual trigger (the co-administration of triptorelin 0.2 mg and recombinant human chorionic gonadotrophin (HCG) [Decapeptyl 0.2 mg + Ovitrelle 250 mu g]) versus standard recombinant HCG (Ovitrelle 250 mu g) affect embryo quality and morphokinetic parameters? Design: Morphokinetic parameters and embryo quality of embryos derived from the first gonadotrophin-releasing hormone (GnRH) antagonist IVF/intracytoplasmic sperm injection (ICSI) cycles triggered by dual trigger or standard HCG trigger in women <= 42 years. Outcome measures included time to pronucleus fading (tPNf), cleavage timings (t2t8), synchrony of the second cycle (s2), duration of the second cycle (cc2) and known implantation data (KID) scoring for embryo quality. Multivariate linear and logistic regression analyses were performed for confounding factors. Results: A total of 4859 embryos were analysed: 1803 embryos from 267 cycles in the dual trigger group and 3056 embryos from 463 cycles in the HCG trigger group. The groups were similar in patient and treatment characteristics apart from a higher maternal body mass index and lower maturation rate in the dual trigger group. Time to second polar body extrusion was shorter in the dual trigger group. Cleavage timings from zygote to an 8-cell embryo did not differ between the two groups. There was a higher percentage of embryos with an optimal cc2 duration in the HCG group. In multivariate logistic regression models, the trigger type was not a significant factor for cell cycle division parameters. Conclusions: Overall, there was no significant difference in the morphokinetic parameters or quality of embryos evaluated using a time-lapse monitoring system between embryos derived following dual trigger compared with HCG.