Visit 1 (pre-progestin treatment), Visit 2 (post-progestin treatment), and Visit 3 (6 month post-LNG only) samples were assayed for their respective progestins in cervical and plasma specimens using LC-MS/MS methodology. Cervical specimens were eluted from ophthalmic sponges using 100% methanol and concentrations of progestins measured in the secretion volumes. Wilcoxon matched-pairs signed rank tests were performed to compare plasma and cervical levels of each progestin for each group with * denoting p<0.05. (A) ETG (n = 6, p = 0.03), (B) MPA (n = 8, p = 0.008), (C) Visit 2 LNG (n = 12, p = 0.002), (D) Visit 3 LNG (n = 3, p = 0.50). There were no detectable progestins in Visit 1 samples (data not shown).