ANOVULATION (lack of ovulation)

For more background information on hormones and their sources, please see The Basics page.

The final endocrinological stage of puberty is the positive estrogen feedback on the pituitary and hypothalamus, which stimulates the midcycle surge of LH necessary for ovulation.  The periods following menarche (first menstrual period) are usually anovulatory, irregular, and may be heavy.