When is a menstrual cycle considered to be irregular?
Hi doctors, I get my period every month on average, but the length of the cycle varies between each month. For example, my cycle length could be 30 days this month, 34 days the next month and then 29 days the following month. The range of variation is usually between 28 - 35 days.
Is some variation in cycle length normal, or would this be considered as an irregular menstrual cycle? What could be some causes of it? Thanks!
Dear Jynnn, thank you for your question. The normal menstrual cycle can vary between 21 and 35 days (most cycle length are between 25 to 30 days).
If the cycle length is more than 35 days, it is considered prolonged.
There are many reasons why your cycle length may be irregular, including:
- Polycystic ovarian syndrome (PCOS)
- Thyroid dysfunction
- High prolactin levels etc.
But if you're having monthly periods, some variation in cycle length may not be much of a concern.
Once blood tests have excluded the common culprits (eg thyroid/prolactin disorders), the main concern would be getting pregnant.
Ovulation occurs 14 days before the next period, and if your cycle length is not consistent, it may be difficult for you to predict when you're going to ovulate, and hence make it difficult to time intercourse.
If you're having difficulty conceiving, you should discuss this with your doctor who will be able to advise you on how to use ovulation testing kits, how to time intercourse and consider whether you need to take any medications.