Embryo quality is more important for younger women whereas age is more important for older women with regard to in vitro fertilization outcome and multiple pregnancy.

OBJECTIVE: To determine the efficiency of embryo scoring systems for multiple pregnancy in women undergoing IVF procedures.
DESIGN: Retrospective record analysis.
SETTING: University hospital, tertiary medical center. PATIENT(S): Three hundred one patients undergoing controlled ovarian stimulation, IVF/intracytoplasmic sperm injection (ICSI), and day 3 embryo transfer. INTERVENTION(S): IVF/ICSI and embryo transfer. MAIN OUTCOME MEASURE(S): Rate of pregnancy and rate of multiple pregnancy. RESULT(S): The score of the best three embryos (Top3) was more correlated with IVF outcome than were the number of good embryos (P=.009) or the cumulative embryo score (P=.038). In the logistic regression model, Top3 was more relevant to IVF outcome and multiple pregnancy for younger patients than was age (P<.05). For older patients, age was more correlated with IVF outcome and multiple pregnancy than was embryo morphology (P<.05). CONCLUSION(S): The embryo morphology criteria can help reduce the number of embryos transferred into younger patients. We could use the age of patients as an indicator to determine the number of embryos transferred into older patients.