trimester

Carboprost (15(S)-15-Methyl Prostaglandin F2α) 是一种前列腺素 F2α 的代谢稳定的合成类似物。它能够刺激子宫收缩并引起流产，可用于子宫收缩乏力引起的产后出血，以及在妊娠中期终止妊娠。

17α-Hydroxyprogesterone (17-OHP) 是一种内源性孕激素，其他类固醇激素（包括糖皮质激素，雌激素，和雄激素）生物合成的化学中间体。

9-deoxy-9-methylene-16,16-dimethyl Prostaglandin E2 (Meteneprost) is a potent analog of prostaglandin E2 with an extended half-life in vivo. In combination with various other prostaglandin derivatives, it results in the termination of first trimester pregnancy in monkeys. A single intramuscular injection containing 0.5 mg of meteneprost and 7.5 mg of 17-phenyl trinor PGF1α is very effective in terminating early pregnancy. This prostaglandin mixture is ineffective on monkeys in their third trimester of pregnancy. Meteneprost, when compared to PGE2 and PGF1α, in monkey and rat, does not result in unwanted side effects such as fever or gastrointestinal problems.

13,14-dihydro-15-keto Prostaglandin E2 (13,14-dihydro-15-keto PGE2) serves as the predominant metabolite of PGE2 in plasma, created through a 15-keto PGE2 intermediate by the action of 15-oxo-PG Δ13 reductase. Unlike its precursor PGE2, this compound exhibits poor binding affinity towards EP2 and EP4 PGE2 receptors (Ki values of 12 and 57 µM, respectively) in CHO cells and fails to stimulate adenylate cyclase activity therein (EC50s >18 and >38 µM, respectively). Concentrations of 13,14-dihydro-15-keto PGE2 are notably higher in the plasma of pregnant women during their third trimester and at labor and delivery stages, whereas its levels are found to be reduced in the tumor tissues of patients with non-small cell lung cancer (NSCLC) compared to adjacent healthy tissue.