You're more likely to get pregnant if you and your partner are both in good health. Making some changes to your lifestyle may improve your chances of getting pregnant and having a healthy pregnancy.
Medical conditions such as diabetes, asthma, obesity and other problems can affect your pregnancy.
About 84% of couples in the general population will conceive within one year if they do not use contraception and have sex regularly. Of those who don't conceive in the first year, about half will do so in the second year.
Being overweight or underweight can affect your chances of conceiving. Too much or too little body fat can make your periods irregular or stop them completely, which can affect your ability to conceive.
Your weight is healthy if your body mass index (BMI) is between 20 and 25. Women whose BMI is more than 30 or under 19 may have problems conceiving. If your partner's BMI is more than 30, his fertility is likely to be lower than normal.
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The Chief Medical Officers for the UK recommend that if you're pregnant, or planning to become pregnant, the safest approach is not to drink alcohol at all, to keep risks to your baby to a minimum.
Your partner should drink no more than 14 units of alcohol a week, which should be spread evenly over three days or more. Drinking alcohol excessively can affect the quality of his sperm.
Smoking may reduce fertility in women, including passive smoking. If you smoke and need help to quit:
There's also a link between smoking and poorer quality sperm, although the effect on male fertility is not certain. However, stopping smoking will improve your partner's general health.
There's no clear evidence of a link between caffeine – which is found in drinks such as coffee, tea and cola – and fertility problems.
A number of prescription, over-the-counter, and recreational drugs interfere with male and female fertility. Talk to your GP if you're concerned.
You're most likely to get pregnant if you have sex within a day or so of ovulation (when your ovaries are releasing an egg). This usually happens about 14 days after the first day of your last period.
An egg lives for about 12-24 hours after it's released. For you to get pregnant, a sperm must fertilise the egg within this time. Sperm can live for up to seven days inside your body.
For the best chance of success, you should have sex every two to three days throughout the month. You don't need to time it to coincide with the days when you ovulate.
If you've been trying for a baby for more than one year without success, see your GP for advice. For more information, see How long does it usually take to get pregnant?
Read the answers to more questions about pregnancy.