What Is Infertility? Causes, Testing and Treatment

What is infertility?

Infertility is the inability to become pregnant after a set period of trying. Most guidance, including from the American Society for Reproductive Medicine (ASRM) and ACOG, uses 12 months of regular, unprotected intercourse for people under 35 and 6 months for people 35 and older. People who cannot carry a pregnancy to a live birth, or who need donor sperm or eggs, may also seek fertility care.

Infertility is a medical condition, not a failure. It affects people of every background, and the cause often has nothing to do with anything you did or did not do.

How pregnancy happens

For a pregnancy to occur, several steps must work together: an ovary releases a mature egg (ovulation), sperm travel through the cervix and uterus into a fallopian tube, a sperm fertilizes the egg, and the resulting embryo implants in the lining of the uterus. A problem at any step can make conception harder. You can estimate when you are most fertile with our ovulation calculator.

Common causes

Causes fall into a few broad groups. More than one often applies.

• Ovulation problems, such as polycystic ovary syndrome (PCOS), thyroid disorders, high prolactin or low ovarian reserve.
• Structural problems, including blocked fallopian tubes, fibroids or polyps, and scarring after infection or surgery.
• Endometriosis, where tissue like the uterine lining grows outside the uterus.
• Male factor issues, such as low sperm count, poor movement, abnormal shape or a blockage.
• Unexplained infertility, when standard tests find no clear cause.

Age matters too. Egg quantity and quality decline gradually from the early 30s and more steeply after about 35, and sperm quality also changes with age, though less predictably.

How infertility is diagnosed

A work-up usually includes a medical history, hormone blood tests, a pelvic ultrasound, a check that the fallopian tubes are open and a semen analysis. It should involve both partners. Read our guide to fertility testing for what each test measures.

Treatment options

Treatment depends on the cause, your age and how long you have been trying. Options range from lifestyle changes and timed intercourse to ovulation induction, IUI, IVF and, for some people, donor eggs, sperm or embryos or surgery. Pregnancy is never guaranteed, and success rates depend heavily on age and diagnosis.

When to seek help

Do not wait a full year if you are 35 or older, have irregular or absent periods, known conditions such as endometriosis or PCOS, a history of pelvic infection or surgery, or a partner with known sperm concerns. Read when to see a fertility specialist.

What a typical evaluation timeline looks like

Many people imagine fertility testing as a long, uncertain process. In practice the first round is usually compact. In the first visit, a clinician takes a history and may order bloodwork and an ultrasound. Within one or two cycles, the semen analysis, hormone results and any tubal test are back. A second visit then pulls everything together into a plan: continue trying with timing, add ovulation medication, move to IUI, or go straight to IVF.

Knowing that the process has a beginning, middle and end can make it feel more manageable. If testing drags on without a clear plan, it is reasonable to ask what the next step is and when it will happen.

Risk factors worth knowing

Some factors make difficulty conceiving more likely. Not all can be changed, and having one does not mean you will be unable to conceive.

• Age, especially for the partner who will carry the pregnancy
• Smoking and heavy alcohol use in either partner
• Weight that is much higher or lower than average
• A history of sexually transmitted infections or pelvic inflammatory disease
• Irregular or absent periods
• Previous pelvic or abdominal surgery
• Some medical conditions, such as thyroid disease, diabetes or celiac disease
• Past cancer treatment, including chemotherapy and radiation
• Exposure to certain chemicals or heat in the workplace, particularly for sperm health

You can read more about habits that matter in nutrition and fertility, weight and exercise and partner health.

Myths that add unnecessary guilt

Infertility attracts more myths than most medical topics, and several of them make people feel responsible for something outside their control.

• “You just need to relax.” There is no good evidence that everyday stress causes infertility. See stress and emotional health.
• “It must be the woman.” A male factor contributes in a large share of couples, which is why both partners should be tested.
• “Adopt and you will get pregnant.” This popular story has no support in research.
• “Use the right position or lie with your legs up.” Positions and gadgets do not change your odds.
• “Birth control caused it.” Most methods are followed by a return to fertility. Ask your clinician about your method if you are concerned.

Different situations, different paths

Infertility looks different depending on who you are. A couple in their late 20s who have tried for a year have a different outlook and plan from a 38-year-old who has tried for six months. A person with irregular cycles from PCOS needs a different first step from someone whose partner has a very low sperm count. Same-sex couples and solo parents may not be “infertile” in the clinical sense yet still need fertility care to conceive. See LGBTQ+ and solo-parent fertility.

Because the right plan depends on the cause, a diagnosis matters. Resist the urge to treat yourself with supplements or products before you know what is going on.

Questions to bring to a first visit

• What are the most likely factors for us, given our ages and history?
• Which tests should we do first, and in what order?
• Could any of my current medications or habits be affecting fertility?
• How long should we try on our own before moving to treatment?
• What would you recommend if the work-up is normal?

Our appointment questions planner lets you tick these off and print them.

Looking after yourself

Infertility can bring grief, stress and strain on relationships. It is reasonable to seek emotional support alongside medical care. See stress and emotional health and our get help now page.