As more and more girls are entering puberty at a younger age, the long term effects of this trend are being investigated.
Childhood obesity is believed to induce puberty earlier, as fat cells produce estrogen.
By altering a girl’s hormonal physiology at a younger age, some researchers believe that a her fertility timeline can also be affected.
In fact, early puberty may decrease a woman’s fertility by disrupting the normal regulation of reproductive hormones.
One theory is that the signalling of kisspeptin, a neuro-hormone involved in reproduction, is disrupted by endocrine signals from fat.
Another theory is that a girl’s circadian clock, which controls sleep-wake cycles, may be disrupted by early puberty. Abnormal sleep-wake cycles can affect the secretion of cortisol, testosterone, and insulin, thus affecting normal reproduction cycles.