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Hints And Tips / My 15 Year old Hasn't Started her Periods yet: Should I be Worried?

My 15 Year old Hasn't Started her Periods yet: Should I be Worried?

By Dr. Kate Dudek

Most girls get their first period around the age of 12; this is usually about two years after the first signs of puberty. In girls, the initial signs of puberty include breast development and growth of pubic hair. Whilst 12 is the average age for menstruation to begin, girls as young as 8 can start their periods. Furthermore, there is evidence that, particularly in some countries, the average age of puberty is falling.
Certainly, 200 years ago it was normal for a girl to start her periods between the ages of 15 and 17. However, nowadays that is the exception, rather than the norm; and up to 98% of girls will have started their periods before their fifteenth birthday.

So should you be worried if your daughter falls into the 2% of girls who have not yet started their periods?

The answer is, probably not. Some teenagers are just ‘late bloomers’ and, as the age of puberty tends to have a familial component, if you started your periods later than many of your friends, it is likely that your daughter will experience a similar thing.

Lifestyle factors can also play a role. Being overweight or underweight can delay the start of puberty, as can excessive exercise. This is why ballerinas and gymnasts very often start their periods later than their counterparts. Having an eating disorder or suffering from intense stress can also delay menstruation. For any of these factors, resolving the underlying issue should rectify the issue; for example, finding a healthy way to lose or gain weight, reducing the intensity of an existing exercise schedule, or identifying and acting to resolve the things that are causing stress.

In some cases there will be an underlying medical issue. Some medications will delay puberty or prevent menstruation, including those used to treat cancer and attention deficit hyperactivity disorder (ADHD). There may be a structural problem whereby part of the reproductive system is missing or blocked. A condition called Mullerian agenesis is characterised by a complete or partial absence of parts of the uterus and vagina. Genetic disorders, including Turner syndrome can delay puberty, as can problems with the hypothalamus or pituitary gland. Hypothalamic dysfunction that occurs before puberty often resolves itself over time. Another medical complication that can cause girls to fail to have regular menstrual cycles is polycystic ovary syndrome (PCOS). PCOS regularly causes menstruation disturbances and females with the condition can struggle to conceive. It is frequently associated with obesity, to the extent that women who have been diagnosed with PCOS experience symptomatic relief upon losing weight. Any of these medical conditions will need to be diagnosed by a doctor, who will then be able to offer advice on the best way of managing the symptoms.  
The medical name for starting your periods later than expected is primary amennorhoea. If your daughter has not had her first period by the age of 15 you may wish to consult a doctor for peace of mind, particularly if she has none of the typical signs of puberty. If, however, her breasts have started to form and she is developing pubic hair, it is very likely that her periods will start in the near future.