Rescue intracytoplasmic sperm injection (ICSI)—salvaging in vitro fertilization (IVF) cycles after total or near-total fertilization failure

The value of second polar body detection 4 hours after insemination and early rescue ICSI in preventing complete fertilisation failure in patients with borderline semen

“…Conflicting results of rescue ICSI have been reported, depending on the sources of oocytes and timing of rescue ICSI performed. As shown in several previously published reports, although 1-day-old oocytes could be normally fertilised by rescue ICSI (Nagy et al 1995;Park et al 2000), the quality of the ensuing embryos was poor and embryonic developmental potential was severely compromised (Morton et al 1997;Yuzpe et al 2000). However, when the timing of recue ICSI was moved from 22 h to 6 h following insemination, significantly higher rates of fertilisation and improved embryonic development were obtained Nagy et al 2006;Zhu et al 2011), suggesting that rescue ICSI is still effective as long as oocytes have not lost their developmental competence at the time point when it is performed.…”

“…Although rescue intra-cytoplasmic sperm injection (ICSI) on 1-day-old oocytes is a backup procedure for complete fertilisation failure or poor fertilisation following conventional IVF, developmental potential of the ensuing embryos is poor due to oocyte ageing (Morton et al 1997;Yuzpe et al 2000;Kuczyński et al 2002). Currently rescue ICSI on 1-day-old oocytes is not recommended for patients with total failure of fertilisation.…”

Timing intercourse to achieve pregnancy Current evidence

“…6 Studies of the timing of fertilization in vitro, including intracytoplasmic sperm injection, also suggest that mature human ova (in metaphase II) have a more limited optimum fertilization window than previously appreciated (hours instead of days). 7 Data indicate that by 16 hours after oocyte recovery, fertilization by standard insemination is poor. 8 Indeed, in vitro fertilization programs generally inseminate ova within 2-6 hours of ovum retrieval in an attempt to optimize fertilization rates.…”

Embryonic Chromosomal Abnormalities Obtained After Rescue Intracytoplasmic Sperm Injection of 1-Day-Old Unfertilized Oocytes

“…Reported fertilization rates using this procedure vary from as low as 28% to as high as 60% (1)(2)(3)5), however; pregnancy rates in general are very low (1-3), and higher 3PN formation has been observed (2,3,6). The timing of rescue ICSI is crucial since as the oocyte ages, the success rate decreases, with decrease in normal fertilization rates and increase in 3PN formation (6).…”

“…The timing of rescue ICSI is crucial since as the oocyte ages, the success rate decreases, with decrease in normal fertilization rates and increase in 3PN formation (6). In a recent report, the ideal timing for ICSI on aged oocytes has been reported to be between 19 and 22 h after initial oocyte insemination (5).…”