BACKGROUND:In women, different events of folliculogenesis can be measured and evaluated using ultrasound (US) technology. The availability of a non-invasive translational non-human primate model to study these processes would represent a major contribution to further advance R&D efforts toward novel therapies in assisted reproduction.METHODS:In our study, follicular growth and ovulation was measured in six cyclic Cynomolgus monkeys using abdominal Doppler US.RESULTS:The mean follicular diameter on cycle day -6 (cycle day 0=day of ovulation) was 3.7mm that increased to 6.8mm on cycle day -1. After ovulation, the mean diameter decreased to 4.6mm, confirming ovulation. The mean percentage of follicular size reduction after ovulation was 31%.CONCLUSION:Ultrasonography in combination with color-flow Doppler imaging was shown to be a useful, non-invasive translational method to measure ovarian follicular growth and occurrence and timing of follicular rupture in Cynomolgus monkeys.