Female infertility: causes, diagnosis and chances of pregnancy

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Zappelphilipp Marx•
A doctor discusses the next treatment steps with a patient in a fertility clinic

Unfulfilled desire to have children is one of the most common concerns seen in gynaecology clinics worldwide. Estimates suggest that about one in six people of reproductive age will experience a period of infertility during their lifetime—regardless of background, sexual orientation or family model. For many this is a mix of hope, disappointment, physical strain and an emotional rollercoaster. The good news: diagnosis and treatment are better researched now than ever before. In this article you will learn what female infertility actually means, which symptoms should make you pay attention, which causes may be involved, how the diagnostic process works and which treatment options you can realistically expect — from cycle optimisation to IVF.

What does infertility mean in women exactly?

The World Health Organization (WHO) defines infertility as a disease of the reproductive system in which a clinical pregnancy does not occur after at least twelve months of regular unprotected sexual intercourse. Current data show that about one in six people of reproductive age worldwide are affected. You can also find this classification in the current WHO factsheet on infertility and in the report “1 in 6 people globally affected by infertility”.

  • Primary infertility: No pregnancy has ever occurred.
  • Secondary infertility: There has been one or more pregnancies in the past, but the desire for a child is currently unfulfilled.

Important is the perspective: infertility does not automatically mean that you will never become pregnant. It initially indicates that fertility is reduced and that a structured evaluation is sensible. At the same time, WHO and professional societies emphasise that infertility should be recognised as a relevant health problem — with fair access to diagnostics and treatment.

Early signs: when should you be alert?

Female infertility is not a single disease but an umbrella term. Some women notice nothing at first — except that pregnancy is taking longer than expected. Others show clear signals early on.

  • very irregular cycles or absent periods
  • very heavy, very light or unusually long bleeding
  • severe menstrual pain, pain during sex or persistent lower abdominal pain
  • signs of hormonal disorders such as increased body hair, hair loss or severe acne
  • recurrent miscarriages or very early pregnancy losses

None of these signs is proof of infertility. However, they are reasons to start documenting your cycle and to discuss fertility and your desire to have children with your doctor.

Common causes of female infertility

Professional societies such as ESHRE and ASRM broadly divide causes into hormonal disorders, anatomical changes, reduced ovarian reserve, genetic and immunological factors, as well as environmental and lifestyle influences. Often several factors occur together.

Hormonal disorders and PCOS

Hormonal cycle problems are among the most common causes worldwide. Polycystic ovary syndrome (PCOS) is particularly prevalent. Typical features are infrequent or absent ovulation, elevated androgen levels and many small follicles on ultrasound.

  • Signs of PCOS: irregular cycles, increased body hair, acne, weight gain, insulin resistance.
  • Typical treatment elements: weight normalisation, exercise, dietary changes, treatment of insulin resistance and medication to induce ovulation.

Ovulation disorders without PCOS

Ovulation can also be absent or too rare without PCOS. Common causes include thyroid disorders, elevated prolactin levels, large weight changes, eating disorders, intensive competitive sport or pronounced stress.

  • Warning signs: very long cycles, absent bleeding, large weight fluctuations.
  • Treatment: stabilising hormone levels, for example thyroid medication, therapy for hyperprolactinaemia and gentle cycle regulation.

Endometriosis

In endometriosis, tissue similar to the uterine lining grows outside the uterus, for example on the ovaries, fallopian tubes or peritoneum. This can lead to inflammation, adhesions and pain — and can significantly reduce fertility.

  • Typical symptoms are severe menstrual pain, pain during sex and chronic lower abdominal pain.
  • Treatment: pain management, hormonal therapy and, when trying to conceive, often minimally invasive surgery, complemented by fertility treatments such as IUI or IVF/ICSI.

Tubal factor: problems with the fallopian tubes

Blocked, scarred or adherent fallopian tubes prevent the egg and sperm from meeting or the embryo from reaching the uterus safely. Common causes are previous pelvic infections, surgery or severe endometriosis.

  • Diagnosis: contrast studies or specialised ultrasound techniques to check tubal patency.
  • Treatment: depending on severity, surgical reconstruction or direct IVF if the tubes are severely damaged.

Uterine factors and fibroids

Uterine malformations, polyps and certain fibroids can disturb implantation and increase miscarriage risk — especially if they deform the uterine cavity.

  • Diagnostics: transvaginal ultrasound, 3D ultrasound and hysteroscopy.
  • Treatment: hysteroscopic removal of septa, polyps or submucosal fibroids when they affect the uterine cavity.

Reduced ovarian reserve and age

With increasing age the number and quality of eggs decline. Some women experience premature ovarian insufficiency well before the usual age of menopause. Surgeries on the ovaries, chemotherapy or radiation can further reduce the reserve.

Helpful markers are the AMH level and the antral follicle count on ultrasound. They do not provide a "crystal ball" prognosis but help derive realistic chances and an appropriate treatment strategy.

Genetic and immunological causes

Certain chromosomal abnormalities, clotting disorders or autoimmune diseases can hinder implantation or lead to recurrent miscarriages. With a relevant history, genetic and immunological tests are often recommended to avoid missing rare but important causes.

Unexplained infertility

In some cases, no clear cause is found despite thorough diagnostics — this is called unexplained infertility. Current evidence-based ESHRE guidelines usually recommend starting with a combination of mild hormonal stimulation and insemination before considering IVF. A concise summary is available in the ESHRE guideline on unexplained infertility and the accompanying patient information.

Diagnostics: how is the assessment carried out?

The fertility evaluation should give you clarity without overburdening you with unnecessary tests. The American Society for Reproductive Medicine has published a clear framework that is often used worldwide as orientation.

  1. History and interview: cycle pattern, previous pregnancies, miscarriages, surgeries, infections, medications, medical history, family history, lifestyle.
  2. Physical and gynaecological examination: weight, blood pressure, thyroid, gynaecological exam with swabs as needed.
  3. Cycle monitoring: documentation of cycle length, bleeding intensity, pain and possible ovulation signs (cervical mucus, temperature chart, ovulation tests).
  4. Hormone profile: FSH, LH, estradiol, AMH, prolactin, TSH and androgens if needed at the start of the cycle to assess ovarian reserve and hormone balance.
  5. Transvaginal ultrasound: uterus, endometrium, ovaries, antral follicles, cysts or fibroids.
  6. Tubal diagnostics: contrast studies or ultrasound techniques to assess fallopian tube patency — depending on risk and findings.
  7. Further imaging and endoscopy: hysteroscopy or laparoscopy if endometriosis, adhesions or structural changes are suspected.
  8. Genetics and immunology: additional tests for recurrent miscarriages, very early ovarian failure or family abnormalities.
  9. Semen analysis: examination of the partner or donor according to current WHO standards (WHO Laboratory Manual 2021) to assess sperm count, motility and morphology.

The ASRM Committee Opinion "Fertility evaluation of infertile women" summarises these steps concisely and emphasises: women under 35 years should begin evaluation after about twelve months without pregnancy, while women aged 35 and older should start after six months. You can find the summary on the ASRM website.

Treatment options: what really helps?

The appropriate therapy depends on cause, age, duration of the desire for children, health risks and your personal priorities. Modern fertility centres typically work with a stepwise plan — from less invasive measures to more complex procedures.

Optimising natural fertility

Before invasive or very expensive steps are taken, it is worth checking basic factors: well-timed intercourse, stress management and habits such as smoking or alcohol. The ASRM statement "Optimizing natural fertility" describes concrete strategies to improve spontaneous chances when trying to conceive.

Medical ovulation induction

If ovulation is rare or absent, medications can stimulate egg maturation. Oral drugs and, if needed, hormonal injections are used to stimulate the pituitary or the ovaries. The goal is a well-monitored, predictable ovulation with as few, well-controlled follicles as possible.

Intrauterine insemination (IUI)

In IUI prepared sperm is placed directly into the uterus at the time of ovulation. It is useful for mildly reduced sperm quality, cervical problems, certain forms of sexual dysfunction or unexplained infertility with otherwise favourable conditions. The ESHRE guideline on unexplained infertility often recommends IUI with mild stimulation as a first active treatment step.

In vitro fertilisation (IVF) and ICSI

In IVF, after hormonal stimulation multiple eggs are retrieved from the ovaries and fertilised with sperm in the laboratory. In ICSI a single sperm is injected directly into the egg. The resulting embryos are transferred to the uterus after a few days. These methods are mainly used for tubal factor, severe male factor, advanced endometriosis or after unsuccessful simpler treatments.

Fertility preservation and donation options

Before treatments that may damage fertility — for example certain chemo- or radiotherapies — cryopreservation of eggs, embryos or ovarian tissue is often recommended. An evidence-based overview is provided in the ESHRE guideline "Female fertility preservation". Depending on the country and legal framework, egg donation, embryo donation or surrogacy may also be options; legal and ethical aspects should be carefully considered.

Success rates and prognosis: what are my chances?

The most common question from couples or individuals is: "How likely is it that treatment will work?" There is no exact number for an individual case, but large registry data show typical ranges. The US health authority CDC, for example, publishes national ART data (Assisted Reproductive Technology) annually with success rates by age group.

  • Under 35 years, success rates per IVF embryo transfer in many registries are in the range of about 40 to 50 percent.
  • Between 35 and 37 years they usually fall to about 30 to 40 percent.
  • Between 38 and 40 years rates are often in the range of about 20 to 25 percent.
  • From the early forties, they decrease per attempt to the low double-digit or single-digit percentage range.

These figures are averages across many clinics and patient groups — your personal prognosis may be better or worse. The "National ART Summary" and state reports in the ART surveillance portal of the CDC give a good impression of real-world data.

More important than a single attempt is the cumulative chance over several well-planned treatment cycles. Time also plays a major role: the older the age, the more egg quality and embryo stability decline. Early counselling and a realistic, joint strategy with your treatment team are therefore central.

Lifestyle, environment and prevention

You cannot influence every cause — but you can modify some risk factors. International organisations such as WHO, ESHRE and ACOG repeatedly emphasise the importance of lifestyle and environmental factors for fertility and pregnancy outcomes.

Lifestyle and nutrition

  • A body weight in the healthy range supports hormonal balance, ovulation and egg quality.
  • Stopping smoking and moderating alcohol intake improve fertility and reduce pregnancy risks.
  • Regular exercise reduces stress, has positive metabolic effects and supports general wellbeing.
  • A Mediterranean-style diet rich in vegetables, fruit, whole grains, legumes and healthy fats is associated in many studies with better fertility parameters.
  • Folic acid is recommended before and at the start of a possible pregnancy to reduce the risk of neural tube defects.

Environmental factors and endocrine-disrupting substances

Certain chemicals — for example some plasticisers, pesticides and industrial chemicals — can interfere with the hormonal system. Expert groups such as ESHRE have produced compact fact sheets on environment and fertility.

  • Avoid heating or storing hot food and drinks in problematic plastic containers where possible.
  • Prefer glass, stainless steel and ceramic, especially for long-term storage.
  • Choose minimally processed foods when possible and read labels critically.

Thinking about fertility preservation early

If you plan to delay having children for professional, personal or health reasons, or if a therapy that could damage the ovaries is planned, early counselling on fertility preservation is worthwhile. Options such as egg or embryo freezing should be considered individually, medically and legally.

Emotional burden: you are not alone

Unfulfilled desire for children is more than a medical diagnosis. Many affected people experience shame, grief, anger, envy or the feeling of having "failed". Treatments can be physically demanding, appointments and costs hard to plan, and waiting times between cycles exhausting.

That is why WHO and professional societies recommend psychosocial support as an integral part of fertility care. This can include specialised counselling at the fertility centre, psychotherapy, coaching, self-help groups or a well-moderated online community. It is important that you have a space where your feelings are acknowledged — regardless of the medical outcome.

When should you seek medical help?

Guidelines from WHO, ASRM and ESHRE recommend similar time points for fertility evaluation:

  • After about twelve months of regular unprotected intercourse without pregnancy in women under 35 years.
  • After about six months without pregnancy in women aged 35 years and older.
  • Regardless of duration, immediately if clear risk factors are present, for example very irregular or absent cycles, known endometriosis, previous severe pelvic infections, very poor sperm quality in the partner or planned therapies that may damage fertility.

The first point of contact is usually your gynaecology clinic. Depending on the findings, you may be referred to a specialised fertility centre that offers more diagnostic and treatment options — from cycle monitoring and IUI to IVF and fertility preservation.

Conclusion: decide informed, step by step

Female infertility is common worldwide, complex — and today more treatable than ever. Causes range from hormonal disorders, endometriosis and tubal problems to uterine changes, genetic and immunological factors, as well as environmental and lifestyle influences. At the same time, a wide range of options is available: thorough diagnostics, evidence-based treatment options, fertility preservation and psychosocial support. The most important step is that you do not face your questions alone. If your desire for children remains unfulfilled or you notice warning signs, an early, well-informed evaluation is worthwhile. Together with your treatment team you can develop a plan that balances medical facts, personal values and financial considerations — and makes the most of your chances to have the child you wish for.

Disclaimer: Content on RattleStork is provided for general informational and educational purposes only. It does not constitute medical, legal, or other professional advice; no specific outcome is guaranteed. Use of this information is at your own risk. See our full Disclaimer.

Frequently asked questions (FAQ)

Experts generally speak of infertility when no pregnancy occurs despite regular unprotected sexual intercourse for about twelve months; for women aged 35 and over or with clear risk factors, evaluation is often recommended already after six months.

Current estimates suggest that about one in six people of reproductive age will experience a period of infertility during their lifetime, so the frequency is high and affects people regardless of origin, relationship form or sexual orientation.

Notable signs include very irregular or absent cycles, extremely heavy or very light bleeding, severe menstrual pain, pain during sex, repeated miscarriages or clear signs of hormonal disorders such as increased hair growth, hair loss or severe acne.

Common causes include hormonal disorders such as PCOS or thyroid problems, endometriosis, blocked or damaged fallopian tubes, uterine changes, reduced ovarian reserve as well as genetic and immunological factors; often multiple reasons occur simultaneously.

Many women with PCOS can achieve pregnancy with a combination of lifestyle changes, treatment of metabolic disorders and targeted ovulation induction; how good the chances are in an individual case depends on age, comorbidities and the severity of the hormonal disorder.

No, depending on the cause simpler steps may be tried first, for example cycle optimisation, lifestyle changes, medical ovulation induction or insemination; IVF or ICSI is usually recommended when these measures are insufficient or when anatomical or male factors make it necessary.

In IUI prepared sperm is inserted directly into the uterus at ovulation, while in IVF fertilisation takes place in the laboratory and an embryo is then transferred to the uterus; IVF is more complex and expensive but usually offers higher success rates per treatment than insemination.

Fertility declines noticeably from the mid-thirties and more rapidly from the early forties; both the chance per cycle and egg quality decrease, while the risk of miscarriage and genetic abnormalities in the embryo increases, which is why early information and planning are important.

Severe underweight or overweight can disrupt the hormonal balance, impair ovulation and increase the risk of complications in pregnancy; a gradual move towards a healthy body weight often improves cycle regularity, metabolism and the success chances of fertility treatments.

Standard recommendations such as folic acid before and at the start of pregnancy are sensible; beyond that, individual preparations can be recommended in specific cases, but dietary supplements should always be discussed with medical professionals and do not replace evidence-based diagnostics or therapy.

No, infertility initially means reduced fertility over a certain period; depending on cause, age and treatment, chances can improve significantly, but there are also situations where having a genetically related child is very difficult or impossible and alternatives such as donation or adoption should be considered.

Many affected people experience grief, anger, shame or guilt; helpful approaches include open conversations with your partner, trusted people, self-help groups or professional support through psychosocial counselling or psychotherapy; it is important to take your feelings seriously and allow yourself to seek help.

An extensive evaluation is usually recommended after about one year without pregnancy in women under 35 or after about six months in women 35 and older; with very irregular cycles, known endometriosis, previous severe infections or planned fertility-damaging therapies, referral to a fertility clinic can be appropriate much earlier.

You can support your fertility by maintaining a healthy lifestyle, treating pelvic infections early, avoiding risky substances, seeking timely counselling on fertility preservation before planned treatments that may damage the ovaries, and discussing your desire for children openly with your doctor.