It’s ‘Sod’s law’ that for years we try not to get pregnant and then when we decide it’s time to start a family at least one in six couples will have trouble getting pregnant.

But actually conceiving a baby is no easy task with healthy, highly fertile couples in prime baby-making condition only have a 20% chance of falling pregnant in any given cycle – no wonder conception is often called a miracle.

When to seek help

If you’re worried, you can speak to your doctor at any time. But, as a rule of thumb, most fertility specialists will say that if the woman is under 35, give it a year before seeking help and if she’s over 35 see a doctor after six months.

If you have a history of endometriosis, polycystic ovarian syndrome or irregular periods, consider seeing your GP earlier so you can find out if you’re ovulating.

What could be wrong?

Boiled down to bare numbers, 35% of the problems will be with women, 35% with men, 20% will be a combination and 10% will be unexplained.

Below are some of the health problems that can hinder conception. But it’s worth remembering that even if you’re diagnosed with one of these, it’s not a life sentence because a vast majority of couples will go on to conceive either naturally or with medical assistance.

Her problems

Ovulation problems

What is it: Some women are not ovulating (i.e. releasing an egg) or are ovulating erratically. This can be caused by variety of factors like hormonal problems, age or being excessively over- or underweight. Your doctor can take a blood test to check if you’re ovulating.

Treatment: This usually involves fertility drugs like Clomid which may be used in combination with artificial insemination.

Endometriosis

What is it: If a woman presents as infertile, this will be the cause in almost a third of cases. This condition is when the lining of the uterus spread through the tubes to areas outside the uterus.

Treatment: Surgical treatment of endometriosis is the most effective method of treatment with an infertile woman with minimal to mild endometriosis. Otherwise IVF is advised.

Polycystic ovarian syndrome (PCOS)

What is it: Affecting about 10% of women, it is a hormonal disorder which causes problems like irregular periods, excessive hair growth and can make it more difficult to conceive.

Treatment: If you are overweight, you will be encouraged to adopt a healthier lifestyle. Those trying to conceive may be prescribed fertility drugs or start IVF.

Fallopian tube problems

What is it: A woman’s fallopian tubes can become blocked or damaged through a previous ectopic pregnancy, surgery or pelvic inflammatory disease. This damage can stop the sperm from reaching the egg. The thing is, most women won’t know they have problems with their tubes until they try to conceive because there are generally no symptoms.

Treatment: This can involve treatment to open the tubes or IVF or similar if the tubes are beyond repair.

Uterus problems

What is it: Fibroids, polyps and other uterine issues can stop a fertilised egg from implanting in the lining.

Treatment: Drugs can be used to shrink the fibroids, or surgery to remove any growths.

His problems

Sperm production problems

What is it: This is the most common cause of male infertility is problems with the sperm production process in the testes. Low numbers of sperm are made and/or the sperm made do not work properly. About two thirds of infertile men have sperm production problems.

Treatment: Many sperm production problems are hard to treat, although those with mild sperm abnormalities have responded to fertility drugs like Clomid. Many couples resort to intrauterine insemination (where warmed sperm are inserted into the woman’s uterus at the time of conception) or IVF.

Blockage of sperm transport

What is it: Obstructions in the tubes leading sperm away from the testes to the penis can cause a shortage of sperm in the ejaculated semen. This is the second most common cause of male infertility and affects about one in five infertile men.

Treatment: Surgery may be required to remove any blockage in the vas deferens or epididymis (the tubes).

Sperm antibodies

What is it: In some men, substances in the semen or blood called sperm antibodies can develop which can reduce sperm movement and block egg binding (where the sperm attaches to the egg) which is essential for fertilisation. About one in every 16 infertile men has sperm antibodies.

Treatment: Prednisolone, a cortisone-like drug, can be used to lower the levels of sperm antibodies in the body. Research has found that prednisolone can decrease sperm antibody concentrations and improve the chances of achieving a natural pregnancy for about one in four couples.

Erectile dysfunction and other sexual problems

What is it: Difficulties with sexual intercourse, such as erection or ejaculation problems, can understandably prevent couples from becoming pregnant.

Treatment: There are many treatments for impotence or ejaculation problems. It’s best to speak with your GP or a fertility expert.

Hormonal problems

What is it: Sometimes the pituitary gland does not send the right hormonal messages to the testes. This can cause both low testosterone levels and a failure of the testes to produce sperm. Hormonal causes of infertility are not very common.

Treatment: Some men do respond to medication.

His and hers

Idiopathic infertility

What is it: This is just another name for unexplained infertility which affects 10% of couples.

Treatment: Since there’s no known cause, there is no treatment so many couples will turn to assisted conception treatments like IVF.