In the United States, the average age of menarche has declined significantly since the mid-nineteenth century
Menarche can be explained as the first menstrual cycle or the first menstrual bleeding that is been experienced by female humans.
Looking at this from social and medical perspectives, it serves as the central event of female puberty, and can be attributed to fertility however, In the United States, the average age of menarche has declined significantly since the mid-nineteenth century
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