Are girls getting their periods earlier? And can parents do anything about it?
Some parents, who are concerned about their daughters ‘growing up too early’, are trying to delay their child’s first period.
Girls generally begin puberty between the ages of eight and thirteen years old. The onset of breast development, known as thelarche, is the initial sign, followed by menarche, the first menstrual period, which occurs 1.5 to three years later. Research shows that girls are starting puberty earlier than previous decades. A global analysis discovered that thelarche began about three months earlier per decade from 1977 to 2013.
In Australia, the average age of menarche is around 12.9 years, but this figure's change over time remains unclear. In the United States, the average age of menarche decreased from 12.5 years in women born between 1950 and 1969 to 11.9 years in those born between 2000 and 2005. However, the data relies on participants remembering their age when they began menstruating, which may be inaccurate due to recall bias.
Precocious puberty refers to breast or pubic hair development before the age of eight in girls, not just early periods. Approximately 3% of children exhibit signs of precocious puberty before age eight. If a child develops breasts, pubic hair, or has their first period before they turn eight, they should consult their family doctor. Around 0.2% of girls have an underlying medical issue causing precocious puberty that requires treatment.
Puberty is initiated by the hypothalamus, a brain region that releases gonadotropin-releasing hormones (GnRH). These hormones trigger a series of chemical messengers for puberty, leading to the hypothalamus, pituitary gland, and ovaries producing hormones such as LH, FSH, estrogen, and progesterone. Genetic factors play a significant role, with around 400 genes and genetic markers associated with the timing of the first period.
Genetic signals are responsible for about 25% of the variance in the age at menarche, while other factors account for the remaining 75%. Body weight, diet, exercise, endocrine-disrupting chemicals, and family circumstances also influence puberty timing, but the interplay of these factors makes it challenging to determine causation.
Written by urgent.news from The Conversation AU's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
