Dr Phil Kieran: My sporty teenager has yet to get her periods

Given that your daughter has never had a period and is now 15, she falls outside the normal range for periods to start. At this point, I would suggest bringing her to her GP for some baseline investigations and an examination to see if there is a specific cause.

The first thing I would try to figure out is if she had any other puberty-related physical changes. One of the first notable changes is often breast development, caused by increasing oestrogen levels. If the breasts have developed, we can rule out a good few medical conditions straight away.

It was once accepted that female athletes stopped having periods due to training. I remember learning about very complicated hormonal interactions in college to
explain why this happened. More recent research suggests that this is not an unavoidable part of fitness and can be detrimental to the athlete’s health and performance.

Your daughter runs three times per week, which doesn’t sound excessive. However, it is easy for people to become overly focused on the exertion side of training and neglect the nutrition and rest aspects, which are at least as important.

A good starting point in assessing this would be to chat about her motivation around her exercise regimen. 

I bring this up as sometimes exercise can mask unhealthy beliefs around body shape or, in some cases, an underlying eating disorder. If there isn’t a concern about an eating disorder, I would suggest looking at her BMI. 

To calculate BMI, multiply your daughter’s height in metres and centimetres by itself and divide the weight in kilogrammes by this number. BMI on its own is not a very useful tool. However, we know that for women with a BMI less than 18.5, there is a high chance their menstrual cycle will be suppressed. We also know that getting this number up will often restore normal hormonal function.

If these initial discussions don’t explain why she is not having periods, her GP may suggest some blood tests and an ultrasound to make sure there is no abnormality in her ovaries or hormones.

I would recommend a medical checkup. It is crucial to ensure hormone levels are within normal ranges, as low levels can contribute to weaker bones in later life.