Which hormone is primarily responsible for preparing the reproductive tract for pregnancy?

The hormone that is primarily responsible for preparing the reproductive tract for pregnancy is estrogen. This hormone plays a crucial role in the menstrual cycle and in the preparation of the uterus for implantation of a fertilized egg. Estrogen promotes the growth and thickening of the endometrial lining, making it more receptive to an embryo. It also regulates various reproductive functions and supports the overall development of reproductive tissues.

Gonadotropins, such as luteinizing hormone and follicle-stimulating hormone, are important for the regulation of the reproductive system, but they primarily act in the earlier phases of the reproductive cycle, leading to ovulation and the stimulation of ovarian follicles. They do not directly prepare the reproductive tract for pregnancy in the same manner that estrogen does.

Follicle-stimulating hormone is critical for the development of ovarian follicles, while luteinizing hormone is primarily involved in triggering ovulation and subsequent hormone production from the corpus luteum, but they do not play the primary role in preparing the uterus for pregnancy compared to estrogen.