Triumph Injection (Hydroxyprogesterone Caproate) is a progestin indicated to reduce the risk of preterm birth in women with a singleton pregnancy who have a history of singleton spontaneous preterm birth. The effectiveness of Triumph injection is based on improvement in the proportion of women who delivered < 37 weeks of gestation (14). There are no controlled trials demonstrating a direct clinical benefit, such as improvement in neonatal mortality and morbidity.Progesterone plays a vital role in regulation of the female reproductive system and is important for successful implantation of the embryo and maintenance of pregnancy. It acts by binding to progesterone receptors in the uterus, ovaries, breasts and in the central nervous system. These receptors exist in 2 isoforms, PR-A and PR-B. Progesterone binding to these receptors ultimately leads to regulation of gene transcription. This results in an anti-inflammatory effect which blunts the proinflammatory state that occurs with initiation of labor, and maintains uterine quiescence by stabilizing progesterone acting on the myometrium.