Subfertility: what causes it, how it is investigated, and what treatment involves

What it means and how common it is

Subfertility means taking longer than expected to conceive — the working definition is no pregnancy after a year of regular unprotected sex, or six months if the woman is 35 or older. It is not the same as sterility, and many couples classed as subfertile eventually conceive, with or without treatment.

Roughly one in six couples worldwide is affected. In broad terms, about a third of cases have a female factor, about a third a male factor, and the rest are combined or unexplained.

The 'unexplained' category is large and frustrating, and it does not mean nothing is wrong — it means current tests did not find it. Treatment can still work in that situation.

The causes

In women: ovulation problems (PCOS is the commonest, plus thyroid disease, high prolactin, and low ovarian reserve), blocked or damaged fallopian tubes (often from past pelvic infection, tuberculosis — which is a genuinely important cause in India — or endometriosis), uterine problems such as fibroids, polyps, adhesions or a septum, and endometriosis itself.

In men: low sperm count, poor movement or abnormal shape; varicocele; hormonal problems; infections; undescended testes in childhood; injury, surgery or mumps orchitis; genetic conditions; and blockages. Heat, smoking, alcohol, anabolic steroids and some medicines all contribute.

In both: age, weight at either extreme, tobacco, uncontrolled diabetes and thyroid disease, and untreated sexually transmitted infections. Genital tuberculosis deserves separate mention in India — it is a significant, treatable cause of tubal damage and is often silent.

The tests

For the man, first and always: a semen analysis. It is inexpensive, quick and non-invasive, and it should be done before the woman undergoes any invasive testing. An abnormal result is usually repeated after a few weeks before conclusions are drawn.

For the woman: blood tests for thyroid, prolactin, and hormones including AMH (a marker of ovarian reserve); a progesterone test about a week before the expected period to confirm ovulation; a pelvic ultrasound; and a tubal test — an HSG (X-ray dye test) or a sonosalpingography — to check the tubes are open.

Further tests where indicated: hysteroscopy or laparoscopy to look inside the uterus and pelvis, genetic testing, and screening for tuberculosis where the picture suggests it.

Both partners are tested at the same time. A clinic that begins with months of investigation of the woman while never testing the man is doing it wrong, and this happens often enough in India to be worth saying plainly.

Treatment, cost and choosing a clinic

Treatment follows the cause: ovulation induction with tablets (letrozole or clomiphene) for ovulation problems — inexpensive and effective for many; surgery for fibroids, polyps, endometriosis or a varicocele; antibiotics or anti-tuberculosis treatment for infection; hormone correction for thyroid or prolactin problems; lifestyle change where weight, smoking or alcohol are contributing.

Assisted reproduction where those do not apply or do not work: IUI (washed sperm placed in the uterus) or IVF/ICSI. Our IVF and IUI guide covers what each involves and what they cost.

India regulates this sector under the ART (Regulation) Act 2021 and the Surrogacy (Regulation) Act 2021 — clinics must be registered on the national registry, must not offer sex selection (a separate crime under PCPNDT), and must follow rules on donor gametes and record-keeping. Check registration before you pay anything.

Choosing a clinic: ask for the clinic's own live-birth rates for women of your age (not 'success rates', which can mean pregnancy tests), what is included in a quoted package and what is extra (medicines, freezing, ICSI), how many cycles they recommend before reassessing, and whether they will give you the option of stopping. Be wary of guarantees, of pressure to start IVF before basic tests, and of packages sold on emotion.

When to see a doctor

Seek assessment after a year of trying (six months if the woman is 35 or over), and immediately at any age with: irregular or absent periods, known PCOS or endometriosis, previous pelvic infection, tuberculosis or pelvic surgery, two or more miscarriages, a history of undescended testes, testicular injury or surgery, or difficulty with intercourse.

Same-day: severe pelvic pain, fever with pelvic pain, or a missed period with one-sided pain and bleeding.

This article is general information, not medical advice, and is no substitute for personal medical advice. For any decision about your or your child's health, please consult your doctor.

Frequently asked questions

Q: Is infertility mostly a female problem? — No. Male factors are involved in roughly 40 to 50 per cent of cases, and the semen analysis is the single quickest test in the whole workup. Both partners are investigated together.

Q: Can subfertility be cured with diet, yoga or ayurveda? — General health measures — weight, tobacco, alcohol, sleep, treating anaemia and thyroid disease — genuinely help. Specific alternative treatments do not have evidence for blocked tubes, low sperm counts or absent ovulation, and months spent on them are months of declining ovarian reserve if you are over 35.

Q: How many IVF cycles do people usually need? — Success accumulates over cycles, and many pregnancies come in the second or third. That is also why the financial and emotional plan should be agreed before the first — how many cycles, what budget, and what happens if it does not work.

Q: What about adoption? — A legitimate route, not a consolation prize. In India it runs through CARA, the central adoption authority, with online registration and a defined process. Couples often consider it in parallel with treatment rather than only after everything else has failed.