OBJECTIVE: To define statistical thresholds for the number of embryos to be transferred to achieve an optimal pregnancy rate and keep higher-order multiple conceptions (pregnancy with more than two fetal sacs with cardiac activity) within an acceptable limit. DESIGN: A retrospective review of patient records. SETTING: Private practice assisted reproductive technology (ART) facility. PATIENT(S): Seven hundred fifty-four consecutive patients who underwent IVF-ET from 1994-1996. INTERVENTION(S): Embryo grading and score system used on day 3 of embryo transfer. MAIN OUTCOME MEASURE(S): Implantation, pregnancy, and multiple conception rates. RESULT(S): For women < or =35 years old, transfer of up to four poor-quality, two fair-quality, or two good-quality embryos is optimal to eliminate any risk of higher-order multiple pregnancies. Transfer of four poor-quality, three fair-quality, or two good-quality embryos is recommended for women 36 to 39 years old. In women who are > or =40 years old, five embryos need to be transferred regardless of embryo quality. CONCLUSION(S): The mean cumulative embryo score can be used as a reference to determine an optimal number of embryos to transfer and to predict pregnancy outcome.
OBJECTIVE: To define statistical thresholds for the number of embryos to be transferred to achieve an optimal pregnancy rate and keep higher-order multiple conceptions (pregnancy with more than two fetal sacs with cardiac activity) within an acceptable limit. DESIGN: A retrospective review of patient records. SETTING: Private practice assisted reproductive technology (ART) facility. PATIENT(S): Seven hundred fifty-four consecutive patients who underwent IVF-ET from 1994-1996. INTERVENTION(S): Embryo grading and score system used on day 3 of embryo transfer. MAIN OUTCOME MEASURE(S): Implantation, pregnancy, and multiple conception rates. RESULT(S): For women < or =35 years old, transfer of up to four poor-quality, two fair-quality, or two good-quality embryos is optimal to eliminate any risk of higher-order multiple pregnancies. Transfer of four poor-quality, three fair-quality, or two good-quality embryos is recommended for women 36 to 39 years old. In women who are > or =40 years old, five embryos need to be transferred regardless of embryo quality. CONCLUSION(S): The mean cumulative embryo score can be used as a reference to determine an optimal number of embryos to transfer and to predict pregnancy outcome.