When periods skip for several months after the first period, it is natural to worry. To give the conclusion first, irregularity at this stage is mostly a natural process, and there is no need to worry much in year 1 after the first period.
Menstruation happens through signals exchanged between the brain and the ovaries, and just after the first period this signalling system has not yet matured. It should be judged by how many years have passed since the first period rather than by age.
Is it natural for the cycle to be irregular just after the first period?
The menstrual cycle is the result of signals exchanged between the hypothalamus and pituitary gland in the brain and the ovaries. Just after the first period this signalling system has not yet matured, so ovulation does not occur regularly and the cycle repeatedly becomes shorter and longer. In most cases it settles within 2 to 3 years after the first period.
Not only changes inside the body but also everyday factors affect the cycle. When exam stress, excessive dieting and irregular sleep habits overlap, the cycle can fluctuate more than usual, so these need to be looked at as well.
- Exam stress — continued tension unsettles the hormonal signals
- Dieting — weight loss suppresses the release of the hormones that trigger ovulation
- Lack of sleep — when the daily rhythm is disrupted, the hormonal cycle also falls out of step
Does the standard change depending on how many years it has been?
When judging menstrual irregularity, the number of years since the first period is a more important standard than age. Even the same 40-day cycle can be either a natural process or a sign that needs checking, depending on whether it is year 1 or year 4. For this reason, a consultation does not look at age alone but first confirms when the first period occurred.
The standards for menstrual irregularity in adolescence come from the premise that the ovulation cycle gradually becomes regular over time. In years 1 to 3 a cycle of up to 45 days can be watched, but after year 3 the standard becomes 35 days, and the 90-day standard applies in the same way without exception.
- Years 1 to 3 — look into it if the cycle is shorter than 21 days or longer than 45 days
- After year 3 — check if the cycle is shorter than 21 days or longer than 35 days
- Common standard — always check if periods are skipped for 90 days or more
What should be done if there is no first period by age 15?
The timing of the first period varies widely between individuals, so being later than peers is hard to see as a problem straight away. However, if there has been no first period at all by the age of 15, it is necessary to check whether there is another cause affecting growth or hormone release.
Looking at whether growth speed and other physical changes are progressing in a similar way to peers, along with whether the first period has occurred, helps to estimate the reason, and if needed the exact cause can be confirmed through tests.
Can irregular periods be a sign of polycystic ovary syndrome?
Polycystic ovary syndrome is a condition in which ovulation does not occur smoothly, so the cycle becomes longer or irregular, and it can also appear in adolescence. When irregularity outside the cycle standards repeats, this possibility is considered as well, and changes in the skin and other parts of the body are also checked at that point.
Whether it is polycystic ovary syndrome is not concluded from the shape of the ovaries on ultrasound alone. In adolescence a similar appearance can commonly occur as part of growth, so the cycle record and hormone test results are reviewed together and confirmed slowly over time.
- Changes in acne — it breaks out severely or does not settle easily
- Changes in hair — hair above the upper lip or around the chin becomes thicker and darker
- Changes in skin tone — the back of the neck or the armpits become darker
