NuvaRing^®'s contraceptive effects are the result of several factors:

1. Ovulation inhibition
2. Increased viscosity of the cervical mucus, and
3. Changes to the endometrium

In pharmacodynamic trials, these methods are used to measure ovulation inhibition:

• Vaginal ultrasound scanning
• Measurement of hormones (E2, progesterone, LH, and FSH)

This topic presents evidence from these to demonstrate the quick return to ovulation
after discontinuation of NuvaRing^®.