Estrogen and progesterone are secreted by

Placenta is an organ developed during pregnancy. It facilitates the supply of oxygen and nutrients, and also helps in the removal of carbon dioxide and waste products.

Placenta also acts as endocrine tissue and produces several hormones such as human chorionic gonadotropin, human placental lactogen, estrogen, and progesterone.

Estrogen and progesterone are steroid hormones that help in the regulation of mammalian reproduction. They also regulate the development and function of the uterus, menstruation, and pregnancy.