PMOS (formerly PCO syndrome)
The most common hormonal disorder in young women: egg maturation is delayed, ovulation happens less often – long and irregular cycles are typical. More about PMOS
The irregular cycle.
Hardly any cycle is exactly like the next – a certain amount of variation is completely normal. But if cycle lengths fluctuate strongly, cycles are very long or very short, or menstruation stops altogether, this can make the wish for a child harder to fulfil. The good news: cycle disorders can be clarified – and usually treated well.
Putting it in context
What does "irregular cycle" actually mean?
The menstrual cycle is controlled by a finely tuned hormonal interplay – small variations from cycle to cycle are therefore entirely natural and no cause for concern. You should pay attention if the intervals between your periods fluctuate strongly, if your cycles are persistently very long or very short, if bleeding occurs between periods, or if menstruation stops for an extended time.
Behind such cycle disorders there is often delayed or absent egg maturation: if no ovulation takes place, the period is delayed or does not come at all. This is exactly why an irregular cycle matters when you wish to have a child – and at the same time a valuable clue as to where a work-up is worthwhile.
Video
What does an irregular period indicate?
Priv.-Doz. DDr. Michael Feichtinger explains what an irregular period can indicate – and when a work-up makes sense (video in German).
Possible causes
What can be behind cycle disorders.
An irregular cycle is not a diagnosis but a clue. The most common causes can be narrowed down well with a targeted work-up.
Thyroid
Both an overactive and an underactive thyroid can throw the cycle off balance – and can usually be treated well once clarified.
Stress, weight & exercise
Persistent stress, being significantly over- or underweight and very intensive exercise can disturb the hormonal balance – up to the absence of ovulation and menstruation.
Luteal phase deficiency
If the corpus luteum produces too little progesterone after ovulation, this can show as a shortened second half of the cycle or spotting. More about luteal phase deficiency
Ovarian reserve & approaching menopause
As the ovarian reserve declines, the cycles are often the first thing to change – they become shorter or more irregular. The AMH level provides insight.
Other hormonal causes
Other hormones – such as elevated prolactin – can also affect egg maturation and ovulation. A targeted blood test brings clarity. More about the hormone status
Fertility
Irregular cycle and getting pregnant: why timing is so difficult.
You can only get pregnant on the fertile days around ovulation. With a regular cycle, this window can be narrowed down quite well – with strongly fluctuating cycle lengths, however, ovulation is hard to predict. Cycle apps and calculation models reach their limits here, because they assume a certain regularity. And if no ovulation takes place at all in some cycles, there is no chance of pregnancy in those months – without you noticing.
Our fertile days calculator offers a first point of reference for your personal fertile window – but with irregular cycles it is no substitute for a work-up. If you have been trying in vain to get pregnant for a longer time, or your period stays away, the more direct route is usually the more sensible one: finding out whether and when ovulation takes place – and why the cycle has fallen out of rhythm.
Diagnosis
How the work-up for cycle disorders proceeds.
Instead of puzzling for months, a few targeted examinations bring clarity – step by step and easy to plan.
1
Detailed first consultation
We discuss your cycle history, your medical background and your life situation – for example as part of a first fertility consultation in Vienna, Baden or St. Pölten.
2
Hormone status in our own hormone laboratory
A blood test at the right point in the cycle provides insight into the function of the ovaries, thyroid and pituitary gland. More on our page about the hormone status.
3
Cycle monitoring by ultrasound
Across the cycle we follow follicle maturation, ovulation and the build-up of the uterine lining. This shows us directly whether and when ovulation takes place.
4
Discussion of findings & a joint plan
We discuss all results with you calmly – and develop a treatment path that fits your situation. A semen analysis for the partner usually makes sense too, to complete the overall picture.
Treatment
Treatment paths for an irregular cycle.
Which path is right depends on the cause – and is determined individually by our doctors together with you. Treatment often begins with cycle optimisation: the underlying cause – such as a thyroid disorder or lifestyle factors – is treated, egg maturation is gently supported where needed, and ovulation is precisely identified through cycle monitoring. Many women become pregnant on this path alone.
If that is not enough, hormonal stimulation can specifically bring about egg maturation and ovulation. Depending on the overall picture – for example if further factors such as a reduced semen analysis come into play – an insemination (IUI) or assisted reproduction with IVF or ICSI leads to the goal. Our page on fertility treatments gives an overview of all paths.
Cycle disorders are only one of many possible causes
You will find an overview of all the common reasons for an unfulfilled wish for a child – from female fertility and PMOS to male infertility – on our causes page.
FAQ
Irregular cycle and fertility: your questions.
Can I get pregnant with an irregular cycle?
Yes. An irregular cycle does not mean you cannot get pregnant – but it makes timing more difficult, because ovulation is hard to predict. By clarifying the cause and providing targeted support where needed, the chances can usually be improved considerably.
When is a cycle considered irregular?
Small variations from cycle to cycle are completely normal. What stands out are strongly fluctuating intervals between periods, persistently very long or very short cycles, and menstruation stopping for an extended time. Whether a cycle disorder requiring treatment is present is best clarified by a medical examination – not by a cycle app.
How do I know whether I ovulate?
Ovulation can only be reliably confirmed with medical methods – for example by ultrasound during cycle monitoring combined with hormone values. Basal temperature and ovulation tests can give hints, but are often hard to interpret with irregular cycles. If ovulation does not occur, many women notice nothing at all.
My period has stopped completely – what can be behind it?
There are many possible reasons for absent menstruation – from hormonal disorders such as PMOS to thyroid disease, severe stress or being underweight, through to a declining ovarian reserve. Because the causes are so varied, an absent period should always be clarified medically.
Do cycle apps help with an irregular cycle?
Cycle apps and calculators assume a certain regularity – with strongly fluctuating cycles their predictions become unreliable. As a record of your cycle they are still valuable: your notes help us during the work-up. Our fertile days calculator offers a first point of reference.
Which examinations can I expect for cycle disorders?
At the centre are the detailed consultation, a hormone status from our own hormone laboratory and cycle monitoring by ultrasound. Depending on the findings, further examinations can make sense – such as determining the ovarian reserve via the AMH level or a semen analysis for the partner.
Can stress really upset my cycle?
Yes. Persistent stress can impair egg maturation and ovulation via the hormonal axis between the brain and the ovaries – as can being significantly over- or underweight and very intensive exercise. The cycle often normalises when life circumstances stabilise; a work-up makes sure that no additional cause is present.
When should I book an appointment with an irregular cycle?
If you wish to have a child and your cycle fluctuates strongly or your period stays away, an early work-up is worthwhile – because without reliable ovulation, every further attempt on the off-chance costs valuable time. A non-binding first step is a first consultation or a free info evening.
Your next step
We fulfil your wish for a child!
Instead of puzzling on: a few targeted examinations show why your cycle is out of rhythm – and what helps it.
Or call us: +43 1 877 77 75