Parental Supervision Cited Data from animal studies had already shown that stress early in life could lead to an earlier menarche.

Breast cancer risk increases with early menarche and late menopause, and is reduced by early first full-term pregnancy.

In the general population, breast cancer risk increases with early menarche and late menopause, and is reduced at early first full-term pregnancy.

Among these factors are obesity, a high-fat diet, and reproductive factors such as nulliparity, polycystic ovarian syndrome, early menarche, and late menopause.

The authors of the study postulated that increased exposure to light stimulated earlier menarche.

Some of the aspects of family structure and function reported to be independently associated with earlier menarche:

Risk factors include postmenopausal estrogen therapy, obesity, a high-fat diet, reproductive factors like nulliparity, early menarche and late menopause, polycystic ovarian syndrome, and tamoxifen use.

It has been shown that high levels of Leptin, as usually observed in obese females, can trigger neuroendocrine cascade resulting in early menarche.

The previously reported, positive association between childhood height and adult obesity [ 37 ] may therefore be, in part, due to the earlier menarche of relatively tall girls.

Indeed, girls who undergo early menarche tend to grow somewhat more than girls whose menarche occurs later.