Background Previous studies of the effect of early cumulus cell removal (ECCR) on clinical outcomes remain controversial. Some studies indicated that ECCR combined early rescue ICSI contributed to avoid total fertilization failure, while the other studies demonstrated that ECCR may be detrimental to early embryo development. The aim of this study is to investigate the efficacy and safety of early cumulus cell removal (ECCR) during human IVF.
Methods A retrospective analysis was performed between January 2011 and December 2016. The study enrolled 655 couples who underwent IVF treatments with ECCR. After propensity score matching at a 1:2 ratio, 1310 couples who underwent overnight coincubation of gametes were selected. All data were obtained from the Shanghai First Maternity and Infant Hospital IVF patient database. The main outcome measure was the live birth rate and the secondary outcome measures were the normal fertilization rate, polyspermy rate, available embryo rate, clinical pregnancy rate, miscarriage rate and malformation rate.
Results No significant differences were found in the live birth rate (28.55% vs 28.4%; RR of 1.008; 95% CI: 0.869-1.170; p=0.916), clinical pregnancy rate (48.28% vs 45.16%; RR of 1.069; 95% CI: 0.951-1.202; p=0.268), implantation rate (32.67% vs 33%; p=0.896), miscarriage rate (13.33% vs 9.32%; RR of 1.43; 95% CI: 0.916-2.232; p=0.115), neonatal congenital anomalies rate (1.32% vs 1.01%; RR of 1.306; 95% CI: 0.315-5.417; p=0.713) or birthweight between the two groups. The study showed that ECCR was associated with a significantly lower fertilization rate (73.86% vs 80.12%; p=0.000), normal fertilization rate (2PN)(62.76% vs 69%, p=0.000) and available embryo rate (59.62% vs 62.29%, p=0.001). There were no significant differences in the polyspermy rate (11.10% vs 11.11%, p=0.982) and cleavage rate (93.93% vs 93.50%, p=0.279) between the ECCR group and traditional insemination group.
Conclusions ECCR tended to confer increased risk of a lower available embryo rate but had no negative effect on the live birth rate or the neonatal malformation rate.