Is early embryo cleavage a factor to increase success in all types of ICSI indications?

The authors aimed to compare early embryo cleavage with pregnancy rates in intracytoplasmic sperm injection/embryo transfer (ICSI/ET) cycles due to male infertility or tubal factor infertility (TFI).

412 ICSI/embryo transfer cycles undergoing treatment for over two years were prospectively analyzed; 337 of the cycles were due to male infertility, whereas 75 suffered from tubal factors. Non-early cleaved (NEC) embryos were used for ET in 271 male factor and 67 tubal factor cycles, whereas early cleavage embryos were used for embryo transfer in 66 male factor and eight tubal factor cycles.

In 66 out of 337 cycles (19.58 %) in male factor group and in eight out of 75 tubal factor cycles (10.66%), early cleavage (EC) embryos were obtained (p = 0.069). The clinical pregnancy rate was significantly elevated in EC subgroup (34.8%) compared to NEC subgroup (20.6%) (p = 0.015) in the male factor infertility group. The clinical pregnancy rate was non-significantly elevated in EC subgroup (37.5%) compared to NEC subgroup (23.8%) (p = 0.410) in the TFI group.

The authors found that the implantation and pregnancy success of EC embryos vary with the therapeutic indication. The success rate would be low even with usage of EC embryos in untreated cycles of TFI.