Female infertility: what causes it, and how it's investigated
Female infertility has several distinct causes, and identifying which one applies to you is what a fertility investigation is for. Ovulation problems, tubal blockage, conditions inside the uterus, endometriosis, and age-related decline in egg quality are the main categories — and in some cases, no clear cause is found despite thorough testing.
The main categories of cause
Ovulation disorders
If an egg is not released regularly, conception cannot happen in that cycle. PCOS is the most common cause of irregular ovulation, but thyroid problems and other hormonal imbalances can also disrupt it. Irregular, infrequent, or absent periods are usually the first clue.
Blocked or damaged fallopian tubes
The tubes carry the egg from the ovary to the uterus and are where fertilisation normally happens. Past pelvic infection, previous surgery, or endometriosis can leave them blocked or scarred. Tubal blockage is often silent — it does not usually cause pain or other symptoms on its own — which is why it is specifically tested for rather than assumed absent.
Uterine conditions
Fibroids or polyps inside or distorting the uterine cavity can interfere with an embryo implanting, depending on their size and position. Not every fibroid or polyp affects fertility — many do not — but where one is in the wrong place, it is assessed on its own merits. See fibroids for more detail.
Endometriosis
Tissue similar to the uterine lining growing outside the uterus, commonly on the ovaries or pelvic lining, can affect fertility as well as cause pain. It is discussed in more detail on the laparoscopic surgery page, since laparoscopy is often how it is diagnosed and treated together.
Age-related decline
Both the number and quality of a woman's eggs decline with age, and the pace of that decline speeds up from the mid-thirties onward. This is a normal biological process rather than a disorder, but it is a real factor in how long conceiving takes and which treatment is likely to help.
Unexplained infertility
In some couples, thorough investigation of both partners finds nothing abnormal. This does not mean nothing is wrong — it means current tests cannot identify the specific cause — and treatment can still proceed based on what has, and has not, been tried.
How investigation typically proceeds
A fertility work-up usually starts with a detailed history — your cycle pattern, past pregnancies, previous surgery, and any relevant symptoms — followed by a physical examination. From there:
- Hormone blood tests check whether ovulation is happening regularly and look at the hormones involved in the cycle.
- Ultrasound scan looks at the uterus and ovaries, checking for fibroids, polyps, cysts, and the number of follicles present.
- A tubal patency test checks whether the fallopian tubes are open, where the history or initial findings suggest it is needed.
- Further tests are added selectively, based on what the first round of results shows, rather than run as a fixed package for everyone.
Because roughly a third of infertility traces to the woman, a third to the man, and the rest to a combination of both or no clear cause, a semen analysis for the male partner is usually arranged alongside, not after, the female investigation — see male infertility.
What happens after a cause is found
Treatment follows directly from what the investigation shows. Ovulation problems often respond to medication that induces ovulation, sometimes combined with IUI. Tubal blockage, significant endometriosis, or uterine conditions distorting the cavity may need surgical treatment, medication, or a move directly to IVF, which can bypass some tubal and cavity problems altogether. Age-related decline and unexplained infertility are usually discussed in terms of which treatment gives the clearest next step, based on your specific results, rather than a single fixed pathway.
Getting started
Call or WhatsApp us to arrange a first consultation. If you already have previous scan reports, blood test results, or a semen analysis for your partner, bring them along — they help build the picture faster and often mean tests are not repeated unnecessarily. For an overview of the full range of fertility services available, see the fertility and IVF page.
What is the most common cause of female infertility?
Ovulation disorders, of which PCOS is the most common, are among the most frequently identified causes, alongside tubal, uterine, and age-related factors.
Do blocked tubes cause any symptoms?
Usually not. Tubal blockage is often silent, which is why it is specifically tested for as part of a fertility work-up rather than assumed absent because there is no pain.
What if no cause is found?
This is called unexplained infertility. It means current tests have not identified a specific cause — it does not mean treatment cannot proceed, and your consultant will discuss the options based on what has already been tried.
Does age really affect fertility that much?
Yes. Both the number and quality of eggs decline with age, and this is a normal part of the picture your consultant takes into account when discussing timing and treatment options.
This page is for general education and is not personal medical advice. Treatment depends on your own examination and reports, so please speak to a doctor about your situation. We do not carry out or offer sex determination of any kind.