As we all know, uterine fibroids are hormone-dependent tumors which are frequently seen in women aged from 30 to 50 years old. As to the incidence rate of uterine fibroids, females whose first periods comes under 12 years old is much higher than those whose first periods comes after 16 years old. Besides, the fibroids incidence rate of females who have ever given birth to a baby is lower than those females who never give birth to a baby. What the reasons are?

    The primordial follicles of a female are determinate in their life time. During pregnancy and lactation, ovarian suspend ovulation due to hormone effects, until the time of 4 to 6 months of lactation and this may delay a certain number of ovulation. Females who have a history of child-bearing and delivery would be later in their menopausal period. As to those nonparous females, there is a risk of developing hormone-dependent tumors development because of inefficient progestogen protection. Uterine fibroids are popular.