Delayed transfer of embryos from 2 to 3 or 4 days afteroocyte retrieval and the pregnancy rate in ICSI

Background: embryo transfer (et) has traditionally been performed two days afteroocyte retrieval. delaying transfer from day two to day three or four would allow forfurther development of the embryo, might therefore optimize the selection of viable andbest quality embryos for transfer and may be closer to the physiological time of theentry into the uterus than transfer on day two, and might have a positive effect onpregnancy outcomes.objective: the study aimed to determine whether delayed transfer of embryos from 2to 3 or 4 days after oocyte retrieval and the pregnancy rate in icsi (intra cytoplasmicsperm injection) procedure.materials and methods: in this descriptive study we evaluated infertile couples whowere referred to the mehr infertility institute between 2006 and 2008 for icsi,according to the day of embryo transfer. we compared embryo quality, pregnancy rateand implantation rate among day 2, 3 or 4 of transfers.pregnancy rate was confirmed by measurement of β-hcg in serum after 14 days. afterdata collection, analysis was carried out with the t-test and chi squared tests by using thestatistical software package, spss.16.results: the overall clinical pregnancy rate (cpr) reported was 46.6%. the mean ageof women and duration of infertility didn't differ on the day of embryo transfer(p>0.05). overall cprs were not statistically different for day 2 (50.3%), day 3 (46.5%)and day 4 (34.8%) transfers respectively, there were no significant differences in the ageof transferred embryos between pregnant and nonpregnant women (p>0.05).conclusion: from the result of the present study there were no statistically significantdifferences in pregnancy rates according to the day of embryo transfer.