Around 1 in 7 couples may have difficulty conceiving. It's a good idea to see a GP if you have not conceived after a year of trying. 

There are also several factors that can affect fertility. 

These include: 

• Age – fertility declines with age
• Weight – being overweight or obese (having a BMI of 30 or over) reduces fertility; in women, being overweight or severely underweight can affect ovulation 
• Sexually transmitted infections (STIs) – several STIs, including chlamydia, can affect fertility 
• Smoking – can affect fertility: smoking (including passive smoking) affects your chance of conceiving and can reduce semen quality; read more about quitting smoking 
• Alcohol – the safest approach is not to drink alcohol at all to keep risks to your baby to a minimum. Drinking too much alcohol can also affect the quality of sperm (the chief medical officers for the UK recommend adults should drink no more than 14 units of alcohol a week, which should be spread evenly over 3 days or more) 
• Environmental factors – exposure to certain pesticides, solvents and metals has been shown to affect fertility, particularly in men 
• Stress– can affect your relationship with your partner and cause a loss of sex drive; in severe cases, stress may also affect ovulation and sperm production 

There's no evidence to suggest caffeinated drinks, such as tea, coffee and colas, are associated with fertility problems. 

More online information and resources on various topics: 

Trying to get pregnant (nhs.uk) - Information about trying to get pregnant. 

Infertility (nhs.uk) - Information about infertility. 

North east London fertility services - North east London fertility policy