Objective: To describe the magnitude and variability of sequential serum estradiol and progesterone concentrations throughout one depot medroxyprogesterone (DMPA) injection interval.
Design: Prospective study.
Setting: Family planning and women's health clinics.
Patient(s): Thirty-one women, ages 19 to 46, using DMPA for contraception.
Intervention(s): Serum for estrogen and progesterone was collected weekly throughout one DMPA injection interval.
Main outcome measure(s): Serum estradiol and progesterone concentrations; estradiol patterns produced from data plotted across the entire DMPA injection interval.
Result(s): The average daily estradiol concentrations ranged from 7.9 to 69.1 pg/mL, with a mean of 18.9 +/- 12.9 and a median of 15.4 pg/mL. Average daily progesterone concentrations ranged from 0.14 to 1.1 ng/mL, with a mean of 0.40 +/- 0.19 ng/mL and a median of 0.36 ng/mL. Two general patterns of estradiol concentrations were identified. One pattern, observed in approximately one third of the participants, reflected estradiol concentrations that were extremely low (mean, 12.7 +/- 3.6 pg/mL; median, 13.4 pg/mL) and consistently flat across the DMPA injection interval. The second pattern, seen in the remaining participants, reflected estradiol concentrations that were higher (mean, 22.2 +/- 14.9 pg/mL; median, 17.3 pg/mL) and quite variable.
Conclusion(s): This study demonstrated that estradiol concentrations were lower than the 40 to 50 pg/mL reported in most studies and, for the majority of women, varied substantially across the DMPA injection interval.