Magnitude and variability of sequential estradiol and progesterone concentrations in women using depot...

To describe the magnitude and variability of sequential serum estradiol and progesterone concentrations throughout one depot medroxyprogesterone (DMPA) injection interval.

Prospective study.

Family planning and women's health clinics.

Thirty-one women, ages 19 to 46, using DMPA for contraception.

Serum for estrogen and progesterone was collected weekly throughout one DMPA injection interval.

Serum estradiol and progesterone concentrations; estradiol patterns produced from data plotted across the entire DMPA injection interval.

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.

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.