Concerning cervical mucus, which hormone causes it to be clear, watery, and stretchy, indicating peak fertility?

The hormone that causes cervical mucus to become clear, watery, and stretchy during peak fertility is estrogen. During the menstrual cycle, estrogen levels rise in the follicular phase leading up to ovulation. This increase in estrogen promotes changes in the cervical mucus, making it more conducive for sperm transport. The clear, stretchy quality of the mucus, often described as resembling raw egg whites, facilitates the passage of sperm through the cervix and into the uterus, maximizing the chances of fertilization during the fertile window.

Progesterone, while important for preparing the endometrium for potential implantation after ovulation, does not enhance the quality of cervical mucus in the same way. Luteinizing hormone plays a crucial role in triggering ovulation but does not directly affect the properties of cervical mucus. Follicle-stimulating hormone is involved in the growth and maturation of ovarian follicles but has limited direct effects on cervical mucus characteristics. Thus, estrogen is the hormone specifically responsible for producing the optimal cervical mucus that indicates peak fertility.