Infertility is usually defined as the failure of a heterosexual couple to fall pregnant within a year, assuming they are having sex two or three times a week. However the National Institute for Health and Care Excellence (NICE) states that while more than 80 per cent of couples will conceive during this time, half of the remaining couples will fall pregnant given the same conditions over the following year. Alison perhaps need not worry too much yet and instead take the following steps to maximise her chances:

• Have sex every two to three days
• Eat a healthy diet
• Stop smoking, including in passive form
• Cut back on alcohol; one to two units no more than once or twice a week
• Ensure a healthy body mass index – being underweight can be as damaging as being overweight or obese
• Manage stress levels – techniques such as yoga and meditation may help
• Check that none of the medicines she is taking (OTC, prescribed, complementary and supplements) can interfere with fertility, and avoid recreational drugs
• Consider whether any environmental factors may be a problem, such as working in a factory or around chemicals.

Alison should also make sure her smear test and rubella vaccination are up to date, and start taking folic acid supplements.