gynecology

Infertility: Causes, Testing, and What Treatment Actually Involves

By Dr. Adeeb Alshahrour · July 15, 2022

Infertility is common, it is usually explainable, and in most cases something can be done about it. What it is not is a woman's problem to solve alone — a male factor is involved in roughly half of couples, and the single cheapest test in the whole workup is the one done on the man.

This article covers when to get evaluated, what actually causes infertility, what the testing involves and in what order, and how treatment escalates. If you want the practice side of it — what we evaluate and treat here — see our infertility service page.

When trying for a baby becomes infertility

The American Society for Reproductive Medicine sets the threshold for starting an evaluation at:

12 months of regular, unprotected intercourse without pregnancy, if you are under 35
6 months, if you are 35 or older
Immediately — do not wait out a clock — if there is a known reason to expect a problem

That last category matters more than the first two, and it is the one most often missed. Get evaluated now, not in a year, if you have irregular or absent periods, known or suspected endometriosis, a history of pelvic infection or pelvic surgery, two or more miscarriages, prior chemotherapy or pelvic radiation, or a male partner with known testicular problems, prior chemotherapy, or a hernia or varicocele repair. If you are over 40, evaluation and treatment should start straight away.

ASRM broadened the formal definition in 2023 so that it also covers people who need medical help to conceive at all — single people and same-sex couples included — rather than only heterosexual couples who have failed to conceive over time.

Waiting is not neutral. Female fertility declines gradually through the 30s and more steeply after 37, and every month spent waiting for a threshold is a month of that decline.

Causes on the female side

Ovulatory disorders are the largest single category. If you do not release an egg, or release one unpredictably, nothing downstream can work.

PCOS is the most common cause of anovulatory infertility. Irregular or absent periods are the giveaway. It is also very treatable — see our full guide to PCOS diagnosis and treatment.
Thyroid disease and elevated prolactin disrupt ovulation and are both easily tested and easily treated.
Hypothalamic amenorrhea from low body weight, heavy training, or significant stress. Periods stop, and so does ovulation.
Diminished ovarian reserve and age. Egg quantity and quality both fall with age, and quality is the harder problem — it is why miscarriage rates rise alongside conception difficulty.

Tubal disease. Blocked or scarred fallopian tubes prevent egg and sperm from meeting. The usual causes are past chlamydia or gonorrhoea — often with no symptoms at the time — pelvic inflammatory disease, endometriosis, or adhesions from previous abdominal surgery. This is one of several reasons STI testing matters long before you are thinking about pregnancy.

Endometriosis reduces fertility through inflammation, adhesions, and distorted anatomy, and it can be present with nothing but painful periods to announce it. See endometriosis: symptoms, diagnosis, and treatment.

Uterine and cervical factors. Fibroids that push into the uterine cavity, uterine polyps, intrauterine scar tissue, and congenital uterine anomalies can all interfere with implantation. Fibroids sitting on the outside of the uterus generally do not.

Causes on the male side

A male factor is the sole cause in roughly 20% of infertile couples and a contributing factor in another 30–40% — meaning it is part of the picture in something close to half. It is still routinely treated as an afterthought.

Causes include varicocele, prior infection, undescended testicle in childhood, hormonal problems, genetic conditions, obstruction, chemotherapy or radiation, anabolic steroid use, and testosterone therapy — which suppresses sperm production and is a genuinely common and reversible cause. If a man on testosterone is trying to conceive, this needs addressing first.

In a meaningful share of cases no cause is found. Semen quality is nonetheless the fact you need on the table before anyone starts scheduling procedures for the woman.

What the workup actually involves

Order matters. A sensible workup goes cheapest and least invasive first.

Semen analysis. First test, every time. It is inexpensive, non-invasive, and answers roughly half the question. Volume, concentration, motility, and morphology. An abnormal result is repeated after a few weeks before any conclusion is drawn, because semen parameters vary considerably between samples.

Confirming ovulation. Regular, predictable cycles are reasonable evidence you ovulate. Where it is unclear, a mid-luteal progesterone — drawn about seven days before the expected period — confirms it. Home LH kits are useful for timing but only tell you a surge happened.

Baseline bloods. TSH and prolactin, plus androgens and other hormones where PCOS or another endocrine cause is suspected.

Ovarian reserve testing — AMH and an antral follicle count on ultrasound. Here is the caveat that is almost never given honestly: these tests predict how your ovaries will respond to stimulation in an IVF cycle. They are poor predictors of whether you can conceive naturally. ASRM is explicit that a low AMH in someone with untested fertility does not mean she cannot get pregnant, and it should not be sold as a general fertility test.

Checking the tubes and cavity. A hysterosalpingogram (HSG) uses X-ray and contrast to show whether the tubes are open and whether the uterine cavity is normal. Saline infusion sonohysterography gives a better view of the cavity itself and finds polyps and submucosal fibroids that a standard ultrasound misses, though it does not assess the tubes as well. Hysteroscopy allows direct inspection and treatment of anything found in the same procedure.

The treatment ladder

Lifestyle and timing. Modest gains, but real ones, and they cost nothing. Stopping smoking, reducing alcohol, moving toward a healthier weight in either direction, and treating uncontrolled thyroid disease or diabetes. Intercourse every one to two days across the fertile window beats trying to hit a single day.

Ovulation induction. For anovulatory PCOS, letrozole is first-line, ahead of clomiphene — it produces higher ovulation and live birth rates with less risk of twins. Metformin has a role in some cases. Injectable gonadotropins are more powerful, carry a real multiple-pregnancy risk, and need cycle monitoring.

Intrauterine insemination (IUI). Washed, prepared sperm placed directly into the uterus around ovulation, usually combined with ovulation induction. Reasonable for mild male factor, unexplained infertility, cervical factor, and donor sperm. It requires at least one open tube. Success per cycle is modest, and after three or four cycles the sensible move is to escalate rather than repeat.

IVF. Eggs retrieved, fertilised in the laboratory — with ICSI, a single sperm injected into each egg, where male factor is significant — and an embryo transferred. It is the treatment for blocked tubes, severe male factor, advanced age, and anything that has not responded to simpler measures. Success depends heavily on age at egg retrieval.

Surgery, where there is something to correct: myomectomy for cavity-distorting fibroids, hysteroscopic removal of polyps or scar tissue, or laparoscopic treatment of endometriosis.

What a general OB-GYN practice does, and what needs a specialist

Being straight about this saves time and money.

We can do the whole initial evaluation — history for both partners, semen analysis, ovulation confirmation, hormone testing, ultrasound, imaging of the tubes and cavity. We can treat the causes that are ours to treat: thyroid disease, prolactin problems, PCOS, polyps, fibroids, endometriosis. We can run ovulation induction with letrozole and manage the surgical side.

IVF, ICSI, egg freezing, donor gametes, gonadotropin cycles with intensive monitoring, and recurrent implantation failure belong with a reproductive endocrinologist. So does anyone over 40, anyone with very low ovarian reserve, severe male factor, or recurrent pregnancy loss — early, not after a year of trying simpler things.

The failure mode we most want to avoid is a patient spending eighteen months on repeat cycles of something that was never going to work for her particular problem. If the evaluation points to IVF, the useful thing we can do is refer you quickly.

The part nobody tests for

Infertility carries a documented psychological load comparable to other serious medical diagnoses, and the treatment itself adds to it — appointments timed to your cycle, a two-week wait every month, sex that has turned into a task, and other people's pregnancy announcements. Partners often cope on different timetables, which puts strain on the relationship precisely when it is being leaned on.

None of this is a character failure and none of it is optional to acknowledge. Counselling with someone who works in fertility, and peer support, both help. Say so at your appointment; it is a clinical matter, not a distraction from one.

Talk to us

If you are past the threshold for your age, or you have any of the reasons to skip the waiting period, book an evaluation — and bring your partner into it from the start.

Medical disclaimer

This article is general health information, not medical advice for any individual. Fertility testing and treatment depend on your age, history, and your partner's results. Severe pelvic pain, a positive pregnancy test with pain or bleeding, or heavy bleeding during fertility treatment needs urgent assessment — an ectopic pregnancy is a medical emergency.