Infertility is the term used when a pregnancy does not happen after 12 months of regular, unprotected sex. It does not mean a pregnancy is impossible — it means it is worth having a check-up to look for anything that may be getting in the way.

It is a good idea to see a doctor if you have been trying for 12 months without falling pregnant. If you are over 35, it is sensible to seek advice earlier, after about 6 months, because fertility declines with age and there is less time to look into any issues. It is also worth asking sooner if you already know about something that can affect fertility, such as irregular periods, endometriosis, or a past pelvic infection.

About 1 in 6 Australian couples have trouble falling pregnant. Among couples trying for a baby, roughly 85 out of 100 conceive within the first year, and around 95 out of 100 within two years. The causes are spread fairly evenly. Some relate to the woman, some to the man, and some to both. In some couples, no clear cause is found.

Falling pregnant depends on several steps working together: releasing an egg, the egg and sperm meeting, and a fertilised egg settling into the lining of the uterus. A problem at any step can make conception take longer. Fertility can be affected by the woman, the man, or both.

Common factors include:

• Age, which is the single biggest influence on female fertility
• Ovulation problems, so an egg is not released regularly (for example with polyendocrine metabolic ovarian syndrome)
• Blocked or damaged fallopian tubes, sometimes after a past infection
• Endometriosis
• Fibroids
• Weight, both higher and lower than the healthy range

Common factors include:

• A low sperm count, or sperm that do not move well
• Sperm that are an unusual size or shape
• Blockages in the tubes that carry sperm
• Genetic factors

Some things can affect either partner, including smoking, drinking alcohol, some medicines and medical conditions, and increasing age. In some couples the tests are normal and no single cause is found — this is called unexplained infertility, and treatment can still help.

If you have been trying for a while without success, Dr Mahadik can arrange tests for both you and your partner (or donor) to look for anything that may be causing a delay. Testing both partners from the start avoids missing a shared cause.

Tests may include:

• Blood tests to check hormone levels and confirm that ovulation is happening
• An ultrasound to look at the uterus and ovaries
• A test to check whether the fallopian tubes are open
• An AMH blood test to estimate the egg reserve

AMH stands for anti-Müllerian hormone. The test gives an estimate of how many eggs are left in the ovaries, known as the ovarian reserve. It is helpful, but it has real limits, and the result is often given more meaning than it should have.

An AMH result cannot tell you the quality of your eggs, and on its own it does not predict whether you will fall pregnant naturally. Women with a low result and women with a high result fall pregnant naturally at a similar rate, because usually only one egg is released each month either way. Where AMH is genuinely useful is in planning fertility treatment such as IVF, where it helps predict how the ovaries are likely to respond. Dr Mahadik will explain your result alongside your age and the rest of your tests, rather than treating one number as the whole picture.

For men, the main test is a semen analysis. This measures the number of sperm, how well they move (motility), their size and shape (morphology), and the volume and consistency of the sample. Because sperm results can vary, the test is sometimes repeated.

There is no single treatment for infertility. The right plan depends on what the tests show, your age, and how long you have been trying. Care usually starts with the simplest options and moves to more involved treatments only if they are needed. Some treatments are provided in Dr Mahadik's rooms; others, such as IVF, are carried out at a specialist fertility clinic, and she can refer you and stay involved in your care.

For some couples, small changes make a real difference. This can include having regular sex across the fertile window, reaching a healthy weight, stopping smoking, cutting back on alcohol, and reviewing any medicines with a doctor. Do not stop a prescribed medicine without medical advice.

If ovulation is irregular or not happening, medicine can be used to encourage the ovaries to release an egg. This is often one of the first treatments tried, and it is monitored so the response can be checked.

IUI places prepared sperm directly into the uterus around the time of ovulation, giving the sperm a shorter journey to the egg. It is sometimes used for mild male-factor or unexplained infertility, or with donor sperm.

In vitro fertilisation (IVF) involves collecting eggs, combining them with sperm in a laboratory, and transferring an embryo into the uterus. ICSI is a form of IVF where a single sperm is injected into an egg, which can help when there is a male-factor issue. IVF and ICSI are carried out at a specialist fertility clinic.

Success depends heavily on age, along with other personal factors, so a single figure can be misleading. Many people need more than one cycle, rather than falling pregnant on the first attempt. The national YourIVFSuccess estimator gives a personalised estimate based on your own details, and Dr Mahadik or your fertility clinic can talk you through what the numbers mean for you.

Surgery can sometimes treat a cause directly — for example removing fibroids, treating endometriosis, or dealing with a blockage. Depending on the situation, this may be done on its own or alongside other treatment.

PGT is done during IVF to check embryos for certain genetic or chromosomal conditions before transfer. It is only suitable for particular situations, such as when a parent carries a known genetic condition, and is not part of every IVF cycle. Dr Mahadik or your fertility clinic can advise whether it applies to you.

Trying to conceive can be stressful, and it can affect both partners, sometimes in different ways. It helps to talk openly with each other and with your doctor. Counselling and support services are available, and Dr Mahadik can point you to them.

If you have been trying without success, a good first step is to see your GP, who can start some initial checks and refer you to Dr Mahadik. From there she can complete the assessment, start suitable treatment, and refer you to a fertility clinic if that is the right path for you.