MAXIMIZING PREGNANCY RATES AND LIMITING HIGHER-ORDER MULTIPLE CONCEPTIONS BY DETERMINING THE OPTIMAL NUMBER OF EMBRYOS TO TRANSFER BASED ONQUALITY

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 w ith cardiac activity) within an acceptable limit. Design: A retrospect ive review of patient records. Setting: Private practice assisted repr oductive technology (ART) facility. Patient(s): Seven hundred fifty-fo ur consecutive patients who underwent IVF-ET from 1994-1996. Intervent ion(s): Embryo grading and score system used on day 3 of embryo transf er. Main Outcome Measure(s): Implantation, pregnancy, and multiple con ception rates. Result(s): For women less than or equal to 35 years old , transfer of up to four poor-quality, two fair-quality, or two good-q uality embryos is optimal to eliminate any risk of higher-order multip le pregnancies. Transfer of four poor-quality, three fair-quality, or two food-quality embryos is recommended for women 36 to 39 years old. In women who are greater than or equal to 40 years old, five embryos n eed to be transferred regardless of embryo quality. Conclusion(s): The mean cumulative embryo score can he used as a reference to determine on optimal number of embryos to transfer and to predict pregnancy outc ome. (C) 1998 by American Society for Reproductive Medicine.