In order to investigate the ENG/EE CVR’s potential as a method of EC that provides ongoing contraception, we are proposing a pilot study to determine its ability to suppress ovulation when initiated in the late follicular phase. Our primary objective is to determine if the ENG/EE CVR has potential as a method of EC. We hypothesize that the CVR has potential, and will suppress ovulation or cause ovulatory dysfunction in the majority of participants within the 12-14mm and 15-17mm follicle groups.
The proposed study will be comprised of thirty-six healthy, non-pregnant, non-breastfeeding, reproductive age women with regular, ovulatory cycles who are protected from unintended pregnancy via the concurrent use of non-hormonal methods of contraception. Participants will have a mid-luteal screening visit, which will include: informed consent, history, physical, vitals, and assessment of mid-luteal serum progesterone to confirm ovulatory status. Participants will be assigned to one of three groups according the size of the leading follicle (12-14mm, 15-17mm, ≥18mm), which will determine the timing of the insertion of the ENG/EE CVR. Transvaginal ultrasound (TVUS) will be performed three times per week, starting on day 8 of the menstrual cycle, until the leading follicle is within the assigned group. On that day the CVR will be inserted and, including day of insertion, there will be 6 daily visits with hormonal assays (progesterone, luteinizing hormone) and TVUS to assess for signs of ovulation. Compliance with CVR insertion will be assessed through the measurement of serum ENG. After 7 days, the CVR will be removed and the participant will have biweekly visits until onset of menses to obtain serum progesterone levels and TVUS to confirm return to ovulation.