total failure of fertilization after conventional in vitro fertilisation ( ivf ) is documented in around 10 - 25% of cycles . to overcome this barrier of fertilization failure , some investigators have suggested icsi on day 1 of an unfertilized mature oocyte , the so - called  rescue icsi  . factors leading to failed fertilization are defective oocyte , abnormal sperms , improper stimulation protocol , environmental factors , or combination of any of these . traditional techniques which have been used for managing failed fertilization are partial zona dissection , subzonal insemination , and re - insemination but all of these have shown depressed results . rescue icsi is being performed in an attempt to salvage such an event . the pregnancy rate after rescue icsi are lower than fresh icsi due to in vitro aging of the oocytes , poor quality of embryos , and higher incidences of cytogenetic abnormalities in the resulting embryo have been reported when the time interval between oocytes retrieval and fertilization is increased . an asynchrony between embryo development and endometrial secretory pattern can be a contributing factor as well . between may 2007 and may 2012 , 37 rescue icsi procedures have been performed ; of these four patients have conceived with one live birth . we report a case of fertilization failure in ivf cycle , rescued with icsi resulting in a live birth . a 32-year - old patient presented to us with unexplained infertility for 6 years , she had previous six failed ovulation induction ( ovi ) with intrauterine insemination ( iui ) . after performing all baseline investigations including detailed semen analysis , she was recruited for ivf under agonist protocol . downregulation was started in mid - luteal phase using luperide 1 mg daily for 14 days followed by stimulation with recombinant fsh 300iu ( gonal f - merc serono ) daily for 9 days after which eight follicles of 17 - 19 mm were seen with e2 level of 2317 pg / ml . ovulation trigger was given with hcg 10000 iu and 36 hours later total 6 oocytes were retrieved under general anesthesia by transvaginal ultrasound - guided aspiration . the cumulus  oocytes complex was inseminated 4 hours after ovum pick up with 70000 motile spermatozoa in a 50-l embryo culture medium microdroplets under mineral oil and examined for 18 hours postinsemination . none of the oocytes showed any signs of fertilization i.e. , presence of two pronuclei ( 2 pn ) and two polar bodies therefore after an informed consent decision was taken to perform rescue icsi on day 1 with sperm from day 0 insemination . three good quality embryos ( two 6-celled and one 4-celled ) were transferred on day 3 after rescue icsi . progesterone supplementation was started from the day of oocyte retrieval in the form of intramuscular micronized progesterone 100 mg daily . a clinical pregnancy was confirmed at 6 weeks by a positive fetal heart beat on transvaginal sonography . she underwent lower segment cesarean section at 38 weeks in view of patients choice and delivered a healthy normal baby weighing 2.7 kg . fertilization is a complex procedure involving an interaction between sperm and oocytes . for a couple it may be disappointing if there is no embryo transfer due to total fertilization failure during an ivf cycle . in such a case rescue icsi may be attempted to salvage an ivf cycle by increased fertilization with an ensuing embryo formation . rescue icsi can result in good fertilization rates but it may not translate into pregnancy . this poor outcome can be attributed to oocyte aging as oocyte have an optimum period for fertilization that results in viable embryos . fertilization failure is a known complication of conventional ivf cycles which not only causes psychological trauma to the infertile couple but also increases the economical burden . rescue icsi was introduced in 1993 to overcome this catastrophe of failed fertilization but it remains controversial till date . some studies have not proved it to be beneficial ; however , the success rate following rescue icsi in terms of achieving fertilization is 28 - 60% with a pregnancy rate as high as 38% . the outcome of rescue icsi is uncertain due to aged oocyte , poor embryo quality , and chances of cytogenetic abnormality but still it can be performed as the last ray of hope in case of failed fertilization . at our center , fertilization failure is seen in approximately 12 - 15% cases of conventional ivf cycles . we routinely perform icsi in all the cases of male factor infertility and cases with previous failed ivf but not infertile couple with unexplained infertility . this is not only time consuming but also overcome the selection barrier and affects quality of embryo . however , as seen in this case of unexplained infertility rescue icsi proved to be a boon for this couple . now we have started performing routine icsi with ivf in all cases of unexplained infertility . based on our experience , we conclude that though the success of rescue icsi is still questionable , this procedure is worth an attempt in order to give the best chance to the couple in that cycle .
in a conventional ivf cycle unexpected complete fertilization failure may occur in 10 - 25% of infertile women . to overcome this barrier of fertilization failure 
 , some investigators have suggested intracytoplasmic sperm injection ( icsi ) on day 1 of an unfertilized mature oocyte , the so called  rescue icsi  . 
 we report a case of fertilization failure followed by rescue icsi resulting in a live birth . 
 although the success of rescue icsi is still questionable , this procedure is worth an attempt in order to give the best chance to the couple in that cycle .