What embryo-produced hormone maintains progesterone and estrogen secretion by the corpus luteum through the first trimester of pregnancy?

Human chorionic gonadotropin

Explanation:

Human chorionic gonadotropin is a hormone produced after the implementation with the function to promote the maintenance of the corpus luteum during the beginning of pregnancy. This is important because hormones produced by corpus luteum, such as progesterone enrich the uterus with f blood vessels so that it can sustain the growing fetus.

Human chorionic gonadotropin is often used in pregnancy tests, since its presence indicates pregnancy.