A cross-sectional study to compare the pharmacokinetics of Sino-implant (II) during four years of use and Jadelle during five years of use by Kenyan women. The active ingredient in both implants is levonorgestrel (LNG) which is a synthetic progestin that has been used in combined oral contraceptives and in progestin-only pills for more than 30 years.~Population: A total of 280 women between the ages of 18 to 44 years who are currently using Sino-implant (II) or Jadelle contraceptive implants will be enrolled in one of six cohorts of women:~Cohort 1: (n=20 Sino-implant (II), n=20 Jadelle) women enrolled 1-3 months before their 6-month insertion anniversary.~Cohort 2: (n=20 Sino-implant (II), n=20 Jadelle) women enrolled 1-3 months before their 12-month insertion anniversary.~Cohort 3: (n=20 Sino-implant (II), n=20 Jadelle) women enrolled 1-3 months before their 24-month insertion anniversary.~Cohort 4: (n=20 Sino-implant (II), n=20 Jadelle) women enrolled 1-3 months before their 36-month insertion anniversary.~Cohort 5: (n=40 Sino-implant (II), n=40 Jadelle) women enrolled 1-3 months before their 48-month insertion anniversary.~Cohort 6: (n=40 Jadelle) women enrolled 2-6 months before their 60-month insertion anniversary.~Women in all cohorts will be followed for up to 6 months.~Study Duration: Up to 6 months of participant recruitment and up to 6 months elapsed after the baseline visit for the second study visits. 15 months total in the field including training, study initiation, recruitment, follow-up, and close-out.~Two blood samples spaced 2 to 6 months apart will be drawn from each woman for hormone measurements.~Primary Objective: To compare total and free levonorgestrel (LNG) plasma concentrations at four years of Sino-implant (II) use to total and free LNG plasma concentrations at five years of Jadelle use in Kenyan women~Secondary Objectives:~To compare total and free LNG plasma concentrations at four years of Sino-implant (II) use to total and free LNG plasma concentrations at four years of Jadelle use~To characterize the total and free LNG plasma concentration-time profiles over four years following Sino-implant (II) and over five years following Jadelle insertion~To characterize the sex hormone binding globulin (SHBG) serum concentration-time profile over four years following Sino-implant (II) and over five years following Jadelle insertion
A cross-sectional study to compare pharmacokinetics of Sino-implant (II) during four years of used and Jadelle during five years of use by Kenyan women.