BACKGROUND: Failed fertilization after IVF occurs in 10-20% of cycles. Conflicting results of rescue fertilization by ICSI have been reported. We therefore compared the success rate in terms of fertilization and pregnancy of cycles in which rescue ICSI was performed with those from a matched control group of primarily ICSI cycles. METHODS: Unfertilized oocytes from IVF cycles with total fertilization failure where at least four metaphase II oocytes were available were treated by ICSI (group I; n = 120). A matched control group was established with patients undergoing ICSI during the same period (group II; n = 280). RESULTS: Both fertilization rate and the proportion of embryos with four blastomeres on day 2 after ICSI were significantly higher in the control group (P < 0.05). Embryo quality, however, was comparable in both groups. The pregnancy rate in the control group was 25.3% whereas in group I with rescue ICSI, no pregnancy was obtained. CONCLUSIONS: Although unfertilized oocytes after IVF can be fertilized by ICSI, the developmental potential of the ensuing embryos is very poor. Therefore, rescue ICSI after total failure of fertilization is not recommended.
BACKGROUND: Failed fertilization after IVF occurs in 10-20% of cycles. Conflicting results of rescue fertilization by ICSI have been reported. We therefore compared the success rate in terms of fertilization and pregnancy of cycles in which rescue ICSI was performed with those from a matched control group of primarily ICSI cycles. METHODS: Unfertilized oocytes from IVF cycles with total fertilization failure where at least four metaphase II oocytes were available were treated by ICSI (group I; n = 120). A matched control group was established with patients undergoing ICSI during the same period (group II; n = 280). RESULTS: Both fertilization rate and the proportion of embryos with four blastomeres on day 2 after ICSI were significantly higher in the control group (P < 0.05). Embryo quality, however, was comparable in both groups. The pregnancy rate in the control group was 25.3% whereas in group I with rescue ICSI, no pregnancy was obtained. CONCLUSIONS: Although unfertilized oocytes after IVF can be fertilized by ICSI, the developmental potential of the ensuing embryos is very poor. Therefore, rescue ICSI after total failure of fertilization is not recommended.
Authors: Hye Jin Yoon; In Hee Bae; Hyoung Jun Kim; Jung Mi Jang; Yong Su Hur; Hae Kwon Kim; San Hyun Yoon; Won Don Lee; Jin Ho Lim Journal: J Assist Reprod Genet Date: 2013-10-10 Impact factor: 3.412
Authors: Rachel S Mandelbaum; Michael S Awadalla; Meghan B Smith; Caroline J Violette; Brittany L Klooster; Rachel B Danis; Lynda K McGinnis; Jacqueline R Ho; Kristin A Bendikson; Richard J Paulson; Ali Ahmady Journal: J Assist Reprod Genet Date: 2021-06-24 Impact factor: 3.357
Authors: Adriana Bos-Mikich; Fabiana F Bressan; Rafael R Ruggeri; Yeda Watanabe; Flávio V Meirelles Journal: Stem Cells Int Date: 2015-11-09 Impact factor: 5.443