Objective: To evaluate the predictive value for implantation and pregnancy rates of the number of embryos that reach the eight-cell stage with less than 20% fragmentation (good quality embryos) on day 3.
Design: Prospective observational study.
Setting: Private IVF center.
Patient(s): One hundred eighty-nine women undergoing IVF, or intracytoplasmic sperm injection with at least four zygotes, who have had three embryos transferred on day 3.
Intervention(s): None.
Main outcome measure(s): Pregnancy rate and implantation rate.
Result(s): All patients (n = 189) had 3 embryos transferred. The patients were divided in five groups according to the number of good quality embryos on day 3 (0, 1, 2, 3, >3; respectively). For the five groups, the pregnancy rates were 2.9%, 33.3%, 45.5%, 39.4%, and 64.3%; the implantation rates were 2.0%, 17.0%, 20.5%, 19.3%, and 35.7%. No statistically significant differences in pregnancy rate or implantation rate were found for groups 1, 2, and 3 (when 1, 2, or 3 good quality embryos were present). The data were also analyzed after pooling these three groups. A statistically significant difference in pregnancy rate and implantation rate was found for group 0 (no good quality embryos), groups 1, 2, and 3 (1, 2, or 3 good quality embryos), and group >3 (>3 good quality embryos).
Conclusion(s): The number of good quality embryos available on day 3 is a strong predictive value for both pregnancy rate and implantation rate. When good quality embryos are present on day 3, only two embryos should be transferred to minimize multiple pregnancies.