What is menarche and when does it happen?
Menarche is a girl’s first menstrual period and an important turning point in puberty. In many populations, including Turkey, the average age of menarche is about 12–13; but the normal range is wide and varies familially. What matters is not a single “correct age” but that the process proceeds within normal limits and in a regular order.
Menarche is not the start of puberty but a relatively late step. Typically breast development begins first, the growth spurt follows, and menarche mostly comes after the peak of this spurt has passed. This sequence also explains what menarche means for growth.
Menarche and height: how much more growth after it?
Because menarche comes after the peak of the growth spurt, girls usually have limited growth ahead after the first period — on average a few centimetres (often ~5–7 cm), with individual variation. That is, menarche is a sign that the major part of growth is complete; but it does not mean growth has stopped entirely.
This information is useful for height prediction and managing expectations. A girl before menarche has significant growth potential, while a girl past menarche has relatively little growth remaining. Bone age and growth velocity help assess this remaining potential more precisely.
The first year and irregular cycles
In the first year after menarche, indeed the first few years, it is very common — and mostly normal — for menstrual cycles to be irregular, because the hormonal system is still maturing. Long gaps between cycles or variable durations can be seen. Over time the cycles usually become more regular.
That said, some situations require evaluation: very painful or very heavy bleeding, cycles that fail to settle into any pattern for a very long time, or the period stopping for a long time after menarche. Especially in girls doing intense sport, a delayed or absent period can be linked to energy intake falling below need (relative energy deficiency) and should be taken seriously.
Approach for families
Preparing for menarche allows a girl to experience it not with anxiety but as natural and healthy development. Talking about the process in advance, in an age-appropriate and non-embarrassing way, and sharing practical information (hygiene, what to expect) is supportive. In an early-developing girl, menarche may come before peers; in this case emotional support is even more important.
If the age of menarche is very early (for example before age 9–10) or much later than expected, these cases should be viewed within the framework of precocious/delayed puberty, and a paediatric endocrinology assessment sought when needed. For most girls, though, menarche is an ordinary developmental step experienced within normal limits. A girl who is prepared, informed and supported meets this period far more comfortably; so addressing the topic in good time and in a positive way is as important as the process itself.