Mechanisms of uterine specificity of vaginal progesterone

In: Human Reproduction · 2000 · vol. 15(suppl 1) , pp. 159–165 · doi:10.1093/humrep/15.suppl_1.159 · PMID:10928427 · W2148092580
article OA: closed CC0 ⤵ 4 in-corpus citations
View on OpenAlex View on PubMed View at publisher
AI-generated summary by claude@2026-06, 2026-06-06

Vaginal progesterone administration resulted in significantly higher endometrial concentrations compared to intramuscular administration, despite lower serum levels, suggesting a direct pathway for uterine specificity.

One-sentence paraphrase of the abstract; not a substitute for reading it. No clinical advice. How this works

Abstract

Endometrial transformations achieved by vaginal progesterone exceed those normally expected from the circulating concentrations obtained, this suggests some degree of direct vagina to uterus transport. We speculate on the different mechanisms involved in uterine specificity of vaginal progesterone and report data of a preliminary randomized study comparing progesterone concentrations in serum and endometrial tissue obtained from hysterectomy specimens after vaginal or i.m. administration. Eight post-menopausal women undergoing transabdominal hysterectomy were randomized to receive either vaginal progesterone gel, 90 mg, or i.m. progesterone formulation, 50 mg, at 08.00 and 20.00 on the day before surgery and at 06.00 on the day of surgery. Venous blood samples for progesterone measurement were drawn at 08.00 on the day before surgery and during the surgery. Endometrial progesterone concentrations were markedly higher in women who received vaginal progesterone (1.38+/-0.66 and 0.38+/-0.19 ng/mg protein, for vaginal and i.m. groups respectively) (P < 0.02) despite lower serum concentrations (4.17 < 0.56 and 32.32+/-11.06 ng/ml, for vaginal and i.m. groups respectively) (P < 0.001). The vaginal route induces endometrial progesterone concentrations that far exceed those expected from the serum progesterone concentrations achieved.

My notes (saved in your browser only)

Citation neighborhood (sparse)

Too few in-corpus citations on either side for a chart; here are the lists.

Cites (1)

Cited by (4)

References (13)

Cited by (4)

Source provenance

openalex
last seen: 2026-06-10T17:14:06.276822+00:00
License: CC0 · commercial use OK