['To examine whether visfatin administration during superovulation improves ovarian response, developmental competence of oocytes, and fertility in aged female mice.', 'Controlled experimental study.', 'University hospital.', 'Two groups of differently aged C57BL female mice (6-11 and 26-31 weeks).', "Female mice were coinjected intraperitoneally with 5 IU pregnant mare's serum gonadotropin (PMSG) and visfatin of various doses (0-500 ng/mL), followed by 5 IU human chorionic gonadotropin (hCG) injection 48 hours later. Then the mice were immediately mated with an individual male. After 18 hours zygotes were cultured, and expression of ovarian visfatin and vascular endothelial growth factor (VEGF) was examined. Potential pregnancies of visfatin-administered aged female mice were monitored for delivery of offspring.", 'Number of zygotes retrieved, embryo developmental competency, fertility potential, ovarian visfatin and VEGF expression.', 'Ovarian visfatin expression was significantly decreased in the aged mice group compared with the young. Visfatin administration significantly increased embryo developmental rate and ovarian visfatin and VEGF expressions in the aged mice. Visfatin-administered aged mice delivered significantly higher numbers of offspring than controls.'] Does administration of visfatin during superovulation improve developmental competency of oocytes and fertility potential in aged female mice?