Evaluation of two incubation environments--ISO class 8 versus ISO class 5--on intracytoplasmic sperm injection cycle outcome.

OBJECTIVE: To evaluate the impact of two different incubation environments-class 8 versus class 5-on embryo quality and pregnancy rate.
DESIGN: Retrospective comparative study.
SETTING: Private fertility and gynecology clinic. PATIENT(S): 123 consecutive intracytoplasmic sperm injection (ICSI) cycles were analyzed from January 2002 to February 2005. Cycles were divided into two groups: in group I (n = 60), the embryo culture was performed in class 8 air quality; in group II (n = 63), the embryo culture was performed in class 5 air quality. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Number of embryos available for transfer, number of good quality embryos transferred, implantation rate, and clinical pregnancy. RESULT(S): Age of women, duration of stimulation, total doses of gonadotropins, endometrial thickness on the day of human chorionic gonadotropin (hCG) administration, number of oocytes metaphase II retrieved, number of embryos available, number of good quality embryos transferred, fertilization and cleavage rates, implantation rate, and clinical pregnancy were not statistically different between the groups. CONCLUSION(S): Our study demonstrated that incubation environment class 8 is as good as incubation environment class 5 when compared in relation to the parameters analyzed. We believe that there is still room for improvement in the overall outcome of ICSI embryos.