Non-invasive translational Cynomolgus model for studying folliculogenesis and ovulation using color Doppler ultrasonography

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 3.7 mm that increased to 6.8 mm on cycle day ?1. After ovulation, the mean diameter decreased to 4.6 mm, 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.