Effect of melatonin on the clinical outcome of patients with repeated cycles after failed cycles of in vitro fertilization and intracytoplasmic sperm injection

To explore whether embryo culture with melatonin (MT) can improve the embryonic development and clinical outcome of patients with repeated cycles after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) failure, immature oocytes from controlled ovarian superovulation cycles were collected for in vitro maturation (IVM) and ICSI. The obtained embryos were cultured in 0, 10^-11, 10^-9, 10^-7 and 10^-5 M MT medium respectively, and 10^-9 M was screened out as the optimal concentration. Subsequently, 140 patients who underwent failed IVF/ICSI cycles received 140 cycles of embryo culture in vitro with a medium containing 10^-9 M MT, these 140 MT culture cycles were designated as the experimental group (10^-9 M group), and the control group was the previous failed cycles of patients (0 M group). The results showed that the fertilization, cleavage, high-quality embryo, blastocyst, and high-quality blastocyst rates of the 10^-9 M group were significantly higher than those of the 0 M group (P < 0.01; P < 0.01; P < 0.0001; P < 0.0001; P < 0.0001). To date, in total, 50 vitrified-warmed cycle transfers have been performed in the 10^-9 M group and the implantation rate, biochemical pregnancy rate and clinical pregnancy rate were significantly higher than those in the 0 M group (all P < 0.0001). Two healthy infants were delivered successfully and the other 18 women who achieved clinical pregnancy also had good examination indexes. Therefore the application of 10^-9 M MT to embryo cultures in vitro improved embryonic development in patients with repeated cycles after failed IVF/ICSI cycles and had good clinical outcomes.Trial registration: ChiCTR2100045552.