When trying to conceive, it is common to start paying closer attention to your menstrual cycle. At that moment, many women realise that their periods do not always follow the same pattern and can vary both in frequency and duration.
In many cases, menstrual irregularity is considered a simple "nuisance" of not much importance. However, in the context of fertility, it can be a sign that something is not working quite right, and, as a result, it can affect the chances of pregnancy.
What is considered an irregular menstrual cycle?
From a medical point of view, a menstrual cycle is considered irregular when its duration is outside the normal range and/or varies too much from one cycle to the next, without maintaining a stable pattern.
In other words, it is not just a matter of menstruation being delayed occasionally. The important thing is whether the cycle is unpredictable or there are repetitions of shorter or longer than usual cycles.
Cycles outside the normal range
In most adult women, a menstrual cycle usually lasts between 21 and 35 days. Therefore, a cycle can be considered irregular if it lasts less than 21 days (very short cycles) or more than 35 days (very long cycles).
Significant variations between cycles
Even when cycles are within the normal range, they can be considered irregular if they vary considerably from one month to the other.
For example, small variations such as going from a 26-day cycle to a 28-day cycle are usually considered normal. On the other hand, we do talk about irregularity when there are clearly variable patterns, such as alternating cycles of 24 days, then 35, 29, and 40 days. In such cases, ovulation can be more difficult to predict.
Is it possible to get pregnant with irregular cycles?
Yes, many women with irregular periods do get pregnant. Although, when ovulation is not regular, it can be more difficult to identify fertile days, and sometimes medical support is needed to improve the chances of pregnancy.
In assisted reproduction , the first step is to identify whether ovulation is takes place and what is causing its irregularity. To do this, it is requested:
- The patient's medical history and menstrual pattern.
- A hormone analysis, depending on the stage of the cycle.
- A transvaginal gynaecological ultrasound scan.
- In some cases, an assessment of the ovarian reserve.
This approach allows us to guide the diagnosis and decide on the most appropriate treatment in each case; from lifestyle changes to ovulation induction treatment, or assisted reproduction techniques.
Having irregular periods while trying to conceive does not always mean there is a serious problem, but it can be a sign of irregular ovulation, hormonal imbalances or other conditions.
Menstrual regularity provides valuable information about how the ovulatory cycle is functioning and, therefore, about pregnancy chances.
Dr Cristina Guix
Gynaecologist specialist in fertility at Barcelona IVF
