Microinjection procedure into suitable and adequate number of oocytes will be performed following oocyte collection procedure. Development of fertilized oocytes will be followed up under suitable laboratory conditions in culture dish (5% CO2, 95% humidity, 37º C temperature). Fertilization rates will be evaluated at the subsequent 18th hour and embryo development will be evaluated at 24th-48th-72nd hours. On 2nd-3rd or 4th day following oocyte collection, maximum 3 embryos having highest quality scores (grade 3 or 4 embryos will be considered to be good quality embryos) will be selected, and will be transferred into intrauterine cavity with accompaniment of ultrasonography. Wallace 23 mm soft catheter (Smiths, England) will be used as transfer catheter. Follicle aspiration and embryo transfer procedures will be performed by same physician in our study.