(prō-jes'tĕ-rōn‵ )

[ progestin + -sterone ]

A steroid hormone, C₂₁H₃₀O₂, obtained from the corpus luteum and placenta. It facilitates implantation by inhibiting uterine motility and stimulates the development of the mammary gland s. Low levels of progesterone in pregnancy are associated with fetal growth restriction. Progesterone supplementation in pregnancy seems to improve this. Progesterone is used to treat patients with menstrual disorders (secondary amenorrhea, abnormal uterine bleeding, luteal phase deficiency) and to manage renal or endometrial carcinoma. In combination with estrogen, it is used for contraception and postmenopausal hormone replacement therapy.SYN: corpus luteum hormone; luteal hormone; progestational hormone; progestin (1).