FIGURE 4.

Number of embryo cryopreservation and embryo transfers, and trends in pregnancy rates per patient by age at embryo cryopreservation. Overall, each patient underwent 1.7 embryo cryopreservations and 2.2 embryo transfers, with increasing numbers with higher age. Furthermore, the pregnancy rate/patient with embryo transfers peaked at the age of 35–37 years. In the group whose embryos were frozen over 38 years of age, reproductive outcome decreased with age at the time of embryo cryopreservation. EC, embryo cryopreservation; ET, embryo transfer.