Objective: To predict the chance of total fertilization failure (TFF) before the day of ovum pickup with known semen and female variables.
Design: A statistical model was constructed to predict TFF by retrospective analysis (2,366 couples) and subsequently tested on a new IVF population (917 couples).
Setting: Academic tertiary referral center.
Patient(s): Three thousand three hundred eighty-three couples who underwent an IVF-ET treatment.
Intervention(s): None.
Main outcome measure(s): The ability to predict the probability of TFF in IVF.
Result(s): Two variables-postwash total progressively motile sperm cell count (postwash TPMC) and number of follicles-were found to be significant. Taking a probability of 25% as an acceptable risk of TFF, we calculated that a postwash TPMC of <1.1 x 10(6) cells results in a risk of TFF of >25%. Low responders (<4 follicles) needed a postwash TPMC of >2.2 x 10(6) cells to reduce the risk of TFF to <25%. High responders (>15 follicles) needed only 0.35 x 10(6) postwash progressively motile spermatozoa.
Conclusion(s): When postwash TPMC and number of follicles are known and an unacceptable TFF outcome is expected, one can propose an ICSI procedure a few days before the day of ovum pickup.