Prediction of IVF/ICSI outcome based on the follicular output rate

This study assessed the true accuracy of follicular output rate (FORT) as a prognostic indicator of response to FSH and reproductive competence after IVF/intracytoplasmic sperm injection. A total of 1643 cycles, including 140 polycystic ovary syndrome (PCOS) patients who underwent ovarian stimulation, were studied. FORT was calculated as the ratio of preovulatory follicle count on the day of stimulation×100/small antral follicle count (3-10mm in diameter) at baseline. Low, medium and high FORT groups were defined according to tertile values. Among 1503 non-PCOS cycles, numbers of retrieved oocytes and of all embryos that could be transferred, as well as rates of good-quality embryos, embryo implantations and clinical pregnancies, progressively increased with FORT. In PCOS patients, FORT were significantly lower in patients who achieved clinical pregnancy compared with those who did not (0.56±0.21 versus 0.66±0.29, P=0.031). Fertilization and good-quality embryo rates were significantly higher with medium FORT than low and high FORT (P=0.001 and P=0.047, respectively). Medium FORT in PCOS patients and high FORT in non-PCOS patients may predict better outcomes for IVF/ICSI.