Changes in cervical mucus during the menstrual cycle

Cervical mucus varies in consistency throughout the different phases of the menstrual cycle. This is due to variations in hormone levels that occur during a woman's menstrual cycle.

During the follicular and luteal phases, cervical mucus is thick and makes it difficult for sperm and infection-causing microorganisms to pass through. In contrast, during the period close to ovulation, the cervical mucus is more watery and allows sperm to pass through so that fertilization can occur.