Female Infertility: Causes, Risk Factors, Testing and Treatment

Difficulty becoming pregnant is common, and it should never automatically be assumed to be the woman's responsibility.

Infertility can result from factors involving the female reproductive system, male reproductive system, both partners, or sometimes no identifiable cause can be found.

According to the World Health Organization (WHO), approximately 1 in 6 people of reproductive age worldwide experience infertility during their lifetime.

Infertility can be emotionally difficult, but many causes can be investigated and some can be successfully treated or managed.

Understanding how fertility works and knowing when to seek professional assessment can help people make informed decisions about their reproductive health.

What Is Infertility?

WHO defines infertility as a disease of the male or female reproductive system characterized by failure to achieve a pregnancy after 12 months or more of regular unprotected sexual intercourse.

However, waiting 12 months before seeking help is not appropriate for everyone.

Age, medical history, menstrual patterns and known reproductive-health conditions can justify earlier investigation.

Primary vs Secondary Infertility

Infertility can be classified as either primary or secondary.

Primary infertility means a pregnancy has never previously been achieved.

Secondary infertility means difficulty achieving another pregnancy after at least one previous pregnancy.

Secondary infertility can occur even when someone previously conceived without difficulty.

Having had a baby before therefore does not guarantee that conception will always happen easily in the future.

Infertility Is Not Only a Women's Issue

Difficulty conceiving should not automatically be attributed to the female partner.

Infertility may involve:

• female reproductive factors,
• male reproductive factors,
• a combination of factors involving both partners,
• or unexplained infertility.

When pregnancy is not occurring in a heterosexual couple, evaluating the male partner—usually beginning with a medical history and semen analysis—is often performed alongside evaluation of the woman.

Both partners deserve appropriate assessment without blame.

How Does Pregnancy Normally Occur?

Several processes need to work successfully for natural conception.

Generally:

1. An ovary releases a mature egg.
2. Sperm travel through the reproductive tract.
3. At least one fallopian tube must allow the sperm and egg to meet.
4. Fertilization occurs.
5. The resulting embryo travels toward the uterus.
6. The embryo successfully implants in the uterine lining.

Problems affecting any of these stages can reduce the likelihood of pregnancy.

What Causes Female Infertility?

Female infertility does not have one single cause.

Problems can involve the:

• ovaries,
• fallopian tubes,
• uterus,
• endocrine or hormonal system,
• or several areas simultaneously.

Age also has an important effect on fertility.

Let's examine the major causes.

1. Age-Related Decline in Fertility

Age is one of the most important influences on female fertility.

Women are born with a finite number of eggs, and both the number and quality of eggs decline with age.

Fertility generally decreases gradually during the reproductive years and declines more significantly as women get older, particularly after the mid-30s.

Increasing age is also associated with a greater likelihood of:

• miscarriage,
• chromosomal abnormalities,
• and certain pregnancy complications.

This does not mean that pregnancy after 35 is impossible.

Many women conceive naturally and have healthy pregnancies in their late 30s and beyond.

It means that the probability of conception generally decreases with age and fertility assessment may be recommended sooner.

2. Ovulation Problems

For pregnancy to occur naturally, an egg generally needs to be released from an ovary.

Problems with ovulation are a common cause of female infertility.

Someone may:

• not ovulate,
• ovulate irregularly,
• or have hormonal conditions interfering with normal egg development and release.

Irregular or absent menstrual periods can sometimes indicate an ovulation problem.

3. Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a common hormonal condition and an important cause of ovulatory infertility.

PCOS can interfere with regular ovulation.

Possible features include:

• irregular menstrual periods,
• infrequent periods,
• excess facial or body hair,
• acne,
• difficulty becoming pregnant,
• and metabolic problems in some people.

Not everyone with PCOS has all these symptoms.

Importantly, having PCOS does not mean pregnancy is impossible.

Lifestyle management, medicines to induce ovulation and fertility treatments can help many people with PCOS become pregnant.

4. Primary Ovarian Insufficiency

Primary ovarian insufficiency (POI) occurs when the ovaries stop functioning normally before approximately age 40.

It is sometimes called premature ovarian failure, although POI is generally the preferred term.

Possible causes include:

• genetic conditions,
• autoimmune disease,
• chemotherapy,
• radiation therapy,
• and sometimes no identifiable cause.

POI is not exactly the same as natural menopause because ovarian activity can sometimes occur intermittently.

5. Diminished Ovarian Reserve

Ovarian reserve refers broadly to the remaining supply of eggs in the ovaries.

The number of eggs naturally decreases with age.

Some women have a lower ovarian reserve than expected for their age because of factors such as:

• genetics,
• ovarian surgery,
• chemotherapy,
• radiation,
• certain medical conditions,
• or unexplained causes.

Tests such as anti-Müllerian hormone (AMH) may contribute information during fertility assessment, but no single ovarian-reserve test can perfectly predict whether an individual woman will or will not become pregnant naturally.

6. Hypothalamic and Pituitary Disorders

The hypothalamus and pituitary gland in the brain help regulate reproductive hormones.

Problems affecting these systems can interfere with ovulation.

One example is functional hypothalamic amenorrhoea, which may occur in association with:

• substantial weight loss,
• inadequate energy intake,
• excessive exercise,
• or significant physical or psychological stress.

Other pituitary or endocrine disorders can also affect reproductive hormone production.

7. Blocked or Damaged Fallopian Tubes

Healthy fallopian tubes are important for natural conception because fertilization usually occurs within a fallopian tube.

If one or both tubes are blocked or badly damaged, sperm may be unable to reach the egg or a fertilized egg may have difficulty reaching the uterus.

Tubal damage can result from:

• previous pelvic infection,
• untreated sexually transmitted infections,
• pelvic inflammatory disease,
• previous abdominal or pelvic surgery,
• endometriosis,
• or other pelvic conditions.

8. Chlamydia and Gonorrhoea

Some sexually transmitted infections can affect fertility if they are not diagnosed and treated.

Chlamydia and gonorrhoea can cause pelvic inflammatory disease (PID).

PID can damage or scar the fallopian tubes.

This can increase the risk of:

• infertility,
• chronic pelvic pain,
• and ectopic pregnancy.

Because chlamydia and gonorrhoea can sometimes cause few or no symptoms, appropriate STI testing is important for sexually active people according to individual risk and local healthcare recommendations.

Condoms can reduce the risk of many sexually transmitted infections.

9. Pelvic Inflammatory Disease

Pelvic inflammatory disease is an infection involving the female reproductive organs.

It commonly occurs when bacteria move upward from the vagina or cervix.

Untreated sexually transmitted infections are an important cause, although PID can occur in other circumstances.

Damage caused by PID can scar the fallopian tubes.

Repeated episodes may further increase the risk of fertility problems.

Prompt diagnosis and antibiotic treatment are important.

10. Endometriosis

Endometriosis occurs when tissue similar to the lining of the uterus grows outside the uterus.

It can affect areas including:

• ovaries,
• fallopian tubes,
• pelvic lining,
• and surrounding structures.

Endometriosis may interfere with fertility through inflammation, scarring, adhesions, ovarian involvement or changes in the pelvic environment.

Possible symptoms include:

• severe menstrual pain,
• chronic pelvic pain,
• pain during or after sex,
• painful bowel movements,
• and difficulty becoming pregnant.

However, some people with endometriosis have few or no obvious symptoms.

11. Uterine Fibroids

Fibroids are noncancerous growths made of muscle and fibrous tissue that develop in or around the uterus.

Fibroids are very common.

Most women with fibroids are not infertile.

Whether a fibroid affects fertility depends particularly on its:

• size,
• number,
• and location.

Fibroids that distort the uterine cavity may be more likely to interfere with implantation or pregnancy than small fibroids located elsewhere.

Treatment is therefore individualized.

12. Uterine Polyps

Endometrial polyps are growths arising from the inner lining of the uterus.

Some polyps may interfere with fertility, particularly depending on their size and location.

Ultrasound, saline-infusion sonography or hysteroscopy may be used to investigate the inside of the uterus when appropriate.

13. Uterine Adhesions

Scar tissue can sometimes form inside the uterus.

Severe intrauterine adhesions are sometimes called Asherman syndrome.

Adhesions can develop after:

• certain uterine procedures,
• pregnancy-related complications,
• or infection.

Significant adhesions may interfere with menstruation, implantation or fertility.

Hysteroscopy can be used for diagnosis and, in appropriate cases, treatment.

14. Congenital Uterine Differences

Some people are born with differences in the structure of the uterus.

Examples include a septate uterus and other Müllerian anomalies.

Some uterine differences have little effect on fertility, while others can be associated with:

• infertility,
• recurrent pregnancy loss,
• or pregnancy complications.

Appropriate imaging can help determine whether a structural difference is clinically significant.

15. Adenomyosis

Adenomyosis occurs when tissue similar to the uterine lining grows within the muscular wall of the uterus.

It may cause:

• heavy menstrual bleeding,
• painful periods,
• pelvic discomfort,
• or no symptoms.

Research suggests adenomyosis may be associated with reduced fertility in some women, but the relationship is complex.

Treatment depends on symptoms, age and fertility goals.

16. Previous Abdominal or Pelvic Surgery

Previous surgery does not automatically cause infertility.

However, some abdominal or pelvic operations can lead to adhesions or scar tissue.

These adhesions may sometimes affect the fallopian tubes, ovaries or other reproductive structures.

The effect depends on the type of surgery and whether complications occurred.

17. Cancer and Cancer Treatment

Some cancers and cancer treatments can affect fertility.

Chemotherapy and radiation therapy may damage eggs or ovarian tissue, depending on factors such as:

• the medicine used,
• radiation location and dose,
• age,
• and baseline ovarian reserve.

Surgery involving reproductive organs can also affect fertility.

People facing cancer treatment who may want children in the future should ideally discuss fertility preservation before treatment begins, when circumstances allow.

Options may include egg, embryo or ovarian-tissue preservation.

Does Abortion Cause Infertility?

This deserves clarification because the original KandyWandy article listed “repeated abortion” as a direct cause of infertility.

A properly performed abortion that does not cause complications is not generally considered a cause of infertility.

The important concern is complications.

For example, an unsafe abortion can cause:

• serious infection,
• injury to reproductive organs,
• uterine damage,
• or pelvic infection.

These complications can potentially affect future fertility.

Similarly, significant infection or uterine scarring following any pregnancy-related procedure may affect fertility.

The accurate message is therefore about complications, not simply a history of abortion.

Does Smoking Affect Female Fertility?

Smoking is associated with reduced fertility.

Tobacco exposure can affect reproductive health and is also associated with numerous other health risks.

People trying to become pregnant should ideally avoid smoking.

Stopping tobacco use benefits fertility, pregnancy health and long-term health.

Does Alcohol Affect Fertility?

Heavy or excessive alcohol consumption may negatively affect fertility and overall health.

For someone actively trying to become pregnant, reducing or avoiding alcohol is a sensible approach.

Once pregnancy occurs, alcohol exposure can harm fetal development, so major health organizations recommend avoiding alcohol during pregnancy.

Does Body Weight Affect Fertility?

Both very low body weight and obesity can be associated with fertility problems in some people.

Weight can affect:

• reproductive hormones,
• menstrual cycles,
• and ovulation.

However, weight is not the only determinant of fertility.

People of many different body sizes can be fertile or infertile.

When weight management is medically appropriate, sustainable changes are preferable to crash dieting.

Does Poor Nutrition Cause Infertility?

Severe undernutrition can disrupt reproductive hormone function and ovulation.

However, ordinary infertility should not simply be blamed on someone's diet.

No particular “fertility food,” tea, herb, supplement or special diet can guarantee pregnancy.

A balanced diet supports general and reproductive health but does not cure conditions such as blocked fallopian tubes, severe endometriosis or significant ovarian insufficiency.

Can Environmental Chemicals Affect Fertility?

Certain environmental and occupational exposures may affect reproductive health.

Potential concerns include exposure to some:

• heavy metals,
• pesticides,
• industrial chemicals,
• and endocrine-disrupting substances.

The effect depends heavily on the chemical, dose, duration and route of exposure.

The original article's vague statement about “ethylene and lead” was not sufficiently accurate to guide readers.

Anyone with significant occupational chemical exposure who is concerned about fertility should discuss the specific substance with an occupational-health or reproductive-health professional.

Does Marijuana Affect Female Fertility?

The relationship between cannabis and female fertility is still being studied.

Because evidence is incomplete and cannabis can have other reproductive and pregnancy-related effects, people attempting pregnancy should discuss cannabis use with an appropriate healthcare professional.

Cannabis should not be treated as an established single cause of female infertility in the way the old article implied.

What About Anabolic Steroids?

Anabolic steroids are particularly well established as a cause of impaired male reproductive function because they can suppress natural testosterone and sperm production.

Hormonal or performance-enhancing drugs can also affect reproductive health in women.

Anyone using anabolic steroids who is concerned about fertility should seek medical advice.

Can Stress Cause Infertility?

Infertility itself can cause substantial emotional stress.

Severe stress can sometimes influence menstrual cycles and ovulation, particularly when associated with functional hypothalamic amenorrhoea.

But telling someone they are infertile simply because they are “too stressed” can be misleading and harmful.

A proper fertility assessment should look for medical and reproductive causes.

What Is Unexplained Infertility?

Sometimes standard fertility investigations do not identify a clear cause.

This is called unexplained infertility.

It does not mean the problem is imaginary.

Rather, it means currently available routine tests have not identified a specific explanation.

Treatment can still be considered based on:

• age,
• duration of infertility,
• previous pregnancies,
• reproductive history,
• and individual circumstances.

When Should You Seek Help for Infertility?

For women younger than 35, fertility evaluation is generally recommended after about 12 months of regular unprotected intercourse without pregnancy.

For women 35 or older, evaluation is generally recommended after about 6 months.

For women over 40, more immediate fertility evaluation may be appropriate.

However, you should not necessarily wait six or twelve months if there is already a reason to suspect a fertility problem.

Earlier assessment may be appropriate with:

• absent or very irregular periods,
• known endometriosis,
• previous pelvic inflammatory disease,
• known tubal disease,
• previous cancer treatment,
• suspected diminished ovarian reserve,
• recurrent pregnancy loss,
• known uterine abnormalities,
• or suspected male-factor infertility.

Both Partners Should Be Evaluated

When pregnancy is not occurring in a heterosexual couple, evaluation should generally consider both partners.

There is little value in putting a woman through months of testing while ignoring a possible male reproductive factor.

A male fertility assessment commonly includes:

• medical and reproductive history,
• physical examination when appropriate,
• and semen analysis.

Female and male evaluations can often occur in parallel.

How Is Female Infertility Investigated?

There is no single test that diagnoses every cause of infertility.

Assessment usually begins with a detailed history.

A healthcare professional may ask about:

• age,
• menstrual cycles,
• previous pregnancies,
• miscarriages,
• sexual history,
• previous infections,
• previous operations,
• medications,
• medical conditions,
• lifestyle,
• and how long pregnancy has been attempted.

Further investigations depend on the individual.

Checking Ovulation

Ovulation may be assessed using menstrual history and, when needed, tests such as:

• blood hormone measurements,
• ovulation predictor tests,
• or ultrasound.

Women with regular menstrual cycles often ovulate regularly, although exceptions occur.

Irregular or absent periods usually deserve further assessment.

Hormone Testing

Depending on symptoms and medical history, blood tests may assess hormones involved in reproduction.

These can include tests relating to:

• ovarian function,
• thyroid function,
• prolactin,
• and ovarian reserve.

Not every patient needs every hormone test.

Testing should answer a specific clinical question.

Ultrasound

A pelvic ultrasound can provide information about the:

• uterus,
• ovaries,
• endometrium,
• follicles,
• fibroids,
• ovarian cysts,
• and some signs of endometriosis or adenomyosis.

Transvaginal ultrasound is commonly used in fertility assessment where appropriate.

Checking the Fallopian Tubes

A test called a hysterosalpingogram (HSG) can help determine whether the fallopian tubes are open.

During the test, contrast material is introduced through the cervix and X-ray images are taken.

Another option in some settings is saline or contrast sonography.

The appropriate investigation depends on the person's history and available healthcare services.

Ovarian Reserve Testing

Tests such as:

• anti-Müllerian hormone (AMH),
• antral follicle count,
• and sometimes follicle-stimulating hormone (FSH)

may provide information about ovarian reserve.

However, these tests have limitations.

They should not be marketed as a simple “fertility score.”

Age remains one of the most important predictors of reproductive potential.

How Is Female Infertility Treated?

Treatment depends entirely on the cause.

Options may include:

• lifestyle or health interventions,
• treatment of underlying endocrine disorders,
• medicines to induce or regulate ovulation,
• surgery for selected reproductive conditions,
• intrauterine insemination,
• in vitro fertilization,
• or other assisted reproductive technologies.

Some people require only one type of treatment, while others need a combination.

Ovulation-Induction Medicines

Women who do not ovulate regularly may sometimes be treated with medicines that stimulate ovulation.

The specific medicine depends on the underlying condition.

For example, treatment for PCOS-related anovulation may differ from treatment for other hormonal disorders.

These medicines require appropriate medical supervision because they can have side effects and may increase the likelihood of multiple pregnancy in some circumstances.

Surgery

Surgery may help certain anatomical causes of infertility, including selected cases involving:

• uterine polyps,
• fibroids affecting the uterine cavity,
• uterine adhesions,
• endometriosis,
• or other structural abnormalities.

Surgery is not automatically necessary for every abnormality.

Potential benefits should be balanced against surgical risks.

What Is IUI?

Intrauterine insemination (IUI) involves placing specially prepared sperm into the uterus around the time of ovulation.

It may be appropriate for certain causes of infertility but is not suitable for everyone.

Success depends on factors including:

• age,
• diagnosis,
• sperm quality,
• tubal function,
• and treatment protocol.

What Is IVF?

In vitro fertilization (IVF) involves stimulating the ovaries, retrieving eggs and combining eggs with sperm in a laboratory.

An embryo may then be transferred into the uterus.

IVF can help overcome certain fertility problems, including:

• severely damaged or blocked fallopian tubes,
• some male-factor infertility,
• some cases of endometriosis,
• and other infertility diagnoses.

IVF does not guarantee pregnancy, and success rates vary substantially with age and other factors.

Fertility Treatment Should Be Individualized

There is no single “best fertility treatment” for everyone.

Treatment decisions should consider:

• the cause of infertility,
• age,
• ovarian reserve,
• semen results,
• duration of infertility,
• previous treatments,
• medical conditions,
• cost and availability,
• personal values,
• and reproductive goals.

WHO's first global infertility guideline, published in 2025, emphasizes progressive, evidence-based and person-centred fertility care.

Can Female Infertility Be Prevented?

Not every cause of infertility is preventable.

Ageing, genetic conditions and some diseases cannot simply be avoided.

However, some reproductive risks can be reduced.

Helpful measures include:

• preventing sexually transmitted infections,
• seeking prompt treatment for suspected STIs,
• avoiding tobacco,
• limiting harmful alcohol consumption,
• maintaining adequate nutrition,
• avoiding unsafe abortion,
• managing chronic health conditions,
• using appropriate workplace protection around reproductive toxins,
• and discussing fertility preservation before treatments such as chemotherapy when possible.

Do Fertility Supplements Work?

Be cautious with supplements marketed as “fertility boosters.”

Many products claim to:

• improve egg quality,
• regulate hormones,
• unblock fallopian tubes,
• increase ovarian reserve,
• or guarantee conception.

Such claims may not be supported by good clinical evidence.

No supplement can physically reopen severely scarred fallopian tubes or reverse the natural ageing of eggs.

Some supplements can also interact with medicines.

Discuss supplements with a healthcare professional, particularly during fertility treatment.

What About Folic Acid?

Folic acid is different from a fertility supplement.

People who may become pregnant are commonly advised to obtain adequate folic acid before conception and during early pregnancy because it reduces the risk of neural-tube defects in the developing baby.

Folic acid does not treat infertility, but it is an important part of preconception care.

Recommended doses can vary according to individual risk and national guidance.

Infertility and Emotional Health

Infertility can affect emotional wellbeing, relationships and finances.

People may experience:

• sadness,
• frustration,
• anxiety,
• grief,
• isolation,
• relationship strain,
• or social pressure.

WHO specifically recognizes that women often bear disproportionate social blame for infertility even when the cause is male or unexplained.

No one should be shamed or blamed for infertility.

Counselling, peer support or psychological care can be valuable alongside medical treatment.

The Bottom Line

Female infertility can result from many different factors, including age-related changes, ovulation disorders, PCOS, blocked fallopian tubes, pelvic infections, endometriosis, uterine abnormalities, fibroids, ovarian disorders and hormonal conditions.

But difficulty becoming pregnant should never automatically be blamed on the woman.

Male factors, combined factors and unexplained infertility are also important.

A fertility evaluation should therefore assess the relevant reproductive factors in both partners when applicable.

For women under 35, investigation is commonly recommended after approximately 12 months of regular unprotected intercourse without pregnancy. From age 35, assessment is generally recommended after about six months, while women over 40 or anyone with known fertility-related medical conditions may benefit from earlier evaluation.

Modern fertility care includes diagnosis of the underlying problem and, where appropriate, treatments ranging from lifestyle and medical management to ovulation-induction medicines, surgery, IUI and IVF.

Most importantly, infertility deserves accurate information, compassionate care and evidence-based treatment—not blame or stigma.

Medical Disclaimer

This article provides general reproductive-health information for an international audience and is not a substitute for individualized fertility assessment, diagnosis or treatment. Causes of infertility and access to fertility investigations and treatments vary between individuals and countries. If you are having difficulty becoming pregnant, have irregular or absent periods, known reproductive-health conditions or concerns about your fertility, consult an appropriately qualified healthcare professional or fertility specialist.

Sources and Further Reading

World Health Organization — Infertility Fact Sheet

https://www.who.int/news-room/fact-sheets/detail/infertility

World Health Organization — Infertility

https://www.who.int/health-topics/infertility

World Health Organization — Guideline for the Prevention, Diagnosis and Treatment of Infertility

https://www.who.int/publications/b/78506

Centers for Disease Control and Prevention — Infertility: Frequently Asked Questions

https://www.cdc.gov/reproductive-health/infertility-faq/index.html

American Society for Reproductive Medicine — Fertility Evaluation of Infertile Women

https://www.asrm.org/practice-guidance/practice-committee-documents/fertility-evaluation-of-infertile-women-a-committee-opinion-2021/

American Society for Reproductive Medicine — Definition of Infertility

https://www.asrm.org/practice-guidance/practice-committee-documents/definition-of-infertility/