Causes of female infertility
The main causes of female infertility fall into four groups: ovulation problems (e.g., PCOS), tubal problems (blockage/damage), problems with the uterus and its lining (fibroids, polyps, adhesions), and reduced ovarian reserve (largely age-related). In some cases, all tests are normal; this is called unexplained infertility. Most causes can be found, and a significant share can be treated. The true cause can only be understood through a comprehensive evaluation.
There is no single answer to the question "Why can't I get pregnant?" Causes on the female side fall into a few main groups, and most of them are understandable. Knowing the cause is the first and most reassuring step on the path to a solution; only a comprehensive evaluation can show which one applies to you.
The overall picture
In female infertility, causes are usually looked for in four areas: ovulation, the tubes, the uterus and ovarian reserve. In addition, there is an unexplained group in which the tests come back normal. More than one cause can also be present in the same couple; that is why the evaluation looks not at a single test but at the whole picture.
Ovulation problems
Pregnancy requires regular ovulation. If ovulation is irregular or does not happen, pregnancy becomes harder. The most common causes are:
- Polycystic ovary syndrome (PCOS) — the most common cause of ovulation disorders,
- Hormonal imbalances such as thyroid or prolactin problems,
- Very low or very high body weight, intense stress or excessive exercise.
Very irregular or very infrequent periods may point to an ovulation problem. In that case, it is appropriate to be evaluated without waiting for the usual waiting period to pass. The good news: most ovulation problems respond well to treatment.
Tubal problems
The fallopian tubes are where the egg and sperm meet. If the tubes are blocked or damaged, this meeting is prevented. Common causes are:
- Previous pelvic infections (some may cause no symptoms),
- Adhesions caused by endometriosis,
- Previous abdominal/pelvic surgery or a history of ectopic pregnancy.
When needed, the condition of the tubes is assessed with a special imaging test (e.g., a dye X-ray/HSG). If the tubes are blocked, insemination is not suitable; IVF comes to the fore.
Problems with the uterus and its lining
For the embryo to implant, the uterus and its lining (endometrium) need to be suitable. Conditions that may affect this include:
- Fibroids (especially those that distort the uterine cavity),
- Polyps,
- Adhesions inside the uterus (synechiae),
- Congenital differences in the shape of the uterus.
Not all of these findings prevent pregnancy; their significance varies with location and size. Your doctor determines whether a fibroid or polyp matters in your case.
Reduced ovarian reserve
A woman is born with all the eggs she will ever have, and this number declines with age. A reduced reserve affects both the chance of conceiving and the response to treatment. Reserve is assessed with tests such as AMH and an ultrasound antral follicle count (AFC) — for details, see ovarian reserve.
A low reserve does not mean "impossible"; but it does show that time matters. That is why an earlier evaluation is recommended for women over 35.
Unexplained infertility
In some couples, all tests (ovulation, tubes, sperm) come back normal, yet pregnancy still does not occur. This is called unexplained infertility, and it is not rare. It does not mean "there is no cause" but rather "the cause could not be shown with current tests." In this situation, options such as insemination (IUI) or IVF can also help.
Which cause applies to you, and the most suitable path forward, is decided together with your doctor after an evaluation of both partners as a couple.
Frequently asked questions
What is the most common cause of female infertility?
Ovulation problems are among the most common causes, and polycystic ovary syndrome (PCOS) stands out among them. However, the 'most common' cause varies from person to person; tubal and uterine problems and reduced reserve are also important causes. The true cause is found through a comprehensive evaluation.
My periods are regular. Could there still be a problem?
Yes. Regular periods usually indicate that ovulation is happening, but causes such as blocked tubes, uterine problems or reduced reserve can also be present alongside regular periods. That is why the evaluation is not limited to looking at the menstrual pattern.
I have a fibroid. Does that mean I can't get pregnant?
Not every fibroid prevents pregnancy. Its effect depends on the fibroid's location, size and pressure on the uterine cavity. Fibroids that distort the cavity in particular may be significant. Your doctor will assess what your fibroid means and whether anything needs to be done.
My ovarian reserve is low. Does that mean IVF won't work?
A low reserve can reduce the chance of conceiving, but it does not mean 'impossible.' Age and reserve are evaluated together; when appropriate, options including IVF are discussed. Your doctor will share realistic expectations based on your test results.
What does unexplained infertility mean?
It means pregnancy does not occur even though the standard tests (ovulation, tubes, sperm) are normal. It is not rare, and it does not mean 'there is no cause' but rather 'the cause could not be shown with current tests.' In this situation, options such as insemination or IVF can also help.
Sources
- World Health Organization (WHO) — Infertility
- ESHRE — Reproductive medicine guidelines
- ASRM — ReproductiveFacts (patient information)
Note: This content was written independently, based on current scientific information published by the institutions above; it is not a direct copy of any text.
This article is for general information only; it is not a diagnosis or treatment recommendation and does not replace a medical examination. Please consult your doctor about your own situation. The content reflects scientific knowledge as of the update date above.