• Weight
  Being very overweight or underweight can make it more difficult to conceive. Dieting is not recommended during pregnancy as this can affect the supply of nutrients to the baby. The Department of Health advises pregnant women, to eat according to their appetite and to keep an eye on weight gain.
  
  It is normal and healthy to gain weight gradually over the course of a pregnancy. Women who are the correct weight for their height should expect to put on around 11.4-15.9 kg during pregnancy. Women who are underweight will probably gain more weight than average (up to 18.2 kg), and those who are overweight should gain less (6.8-11.4 kg).
   
• Diet
  Eating a healthy diet before pregnancy means that the body has adequate stores of vitamins and minerals. A nutritious, well-balanced diet includes foods rich in protein such as meat, fish, eggs and pulses; dairy foods which supply calcium; starchy foods such as cereals, bread, potatoes and pasta; plus plenty of fruit and vegetables that supply vitamins and fibre. It’s best to avoid a lot of sugary, salty or fatty foods.
  
  A well-balanced vegetarian diet should provide all that is needed, but vegans may need to get advice on taking supplements such as calcium, vitamin D and vitamin B12.
  
  An adequate intake of folic acid is particularly important for all women of child bearing age (see below).
  
  There are also certain foods that women should avoid pre-pregnancy. These include:
  • liver
  • unpasteurised dairy products,
  • raw eggs,
  • pâtés,
  • soft cheese.
  Large quantities of vitamin A can harm the developing foetus. This means that high-dose multivitamin supplements should be avoided. Ask your GP or Midwife if you would like more information.
   
• Folic acid
  Folic acid (a B vitamin) is the only vitamin supplement that is recommended to be taken before pregnancy for women who are otherwise eating a balanced diet.
  
  Folic acid is needed for the development of healthy red blood cells. Adequate intake of folic acid also decreases the chance of a baby being born with a defect of the neural tube, where the baby's brain and spinal cord are formed. One example of a neural tube defect is spina bifida, where an area of spinal cord is not properly enclosed. This can cause problems such as paralysis of the legs and lack of control of bladder and bowels. The baby's neural tube is completely formed by the fourth week of pregnancy - when many women have not even realised they are pregnant.
  It is therefore best to start taking folic acid supplements while preparing for pregnancy or as soon as a woman realises she is pregnant. 400 micrograms (mcg, mg) is the recommended daily dose, which is over and above the usual recommended dietary intake of 200 micrograms. Folic acid occurs naturally in fresh dark green vegetables such as broccoli, peas, green beans and spinach. Many breakfast cereals are fortified with folic acid and it is also found in wholemeal bread.
  
  A higher dose of folic acid is recommended for some women. It is very important that women who have previously had a baby with a neural tube defect, or who have epilepsy or diabetes, consult a GP about folic acid supplementation before trying to conceive.

What to avoid

• Smoking
  Most people are aware of the positive health benefits gained from giving up smoking. It is particularly beneficial to stop smoking before becoming pregnant. Smoking may reduce fertility. Smoking during pregnancy is also linked with low birthweight and associated with other risks for the baby such as being born prematurely, death around the time of birth and sudden infant death syndrome (cot death).
  
  Although it can be very difficult to give up smoking, many women find pregnancy is a strong motivation. Many strategies are available to help people quit, such as nicotine replacement therapy or other medicines, and GPs can provide advice about these.
   
• Alcohol
  Most people also realise that excess alcohol is bad for their health, and too much alcohol may decrease fertility. Heavy drinking can also cause problems for a developing baby, and lead to poor growth, intellectual impairment or birth defects (fetal alcohol syndrome). The advice from the government is that women who are trying to conceive, or at any stage during pregnancy, should avoid drinking alcohol. This is particularly important during the first three months of pregnancy, when important organs such as the brain are forming.
   
• Stress
  Ideally, minimise factors that lead to stress and anxiety when preparing for pregnancy. Eating well and getting plenty of exercise and sleep all help.
  
  Hazards at work
  Some working environments can have an impact on fertility and others can pose a risk to a developing baby. Chemicals, lead, anaesthetic gases and X-rays can all be hazardous and women who are routinely exposed to these should seek advice from a GP.

Issues to discuss with a GP

• Existing medical conditions
  It is always best to get advice about any existing medical conditions before trying to conceive. Some conditions are affected by pregnancy and others can have an impact on the developing baby. Prescription medicines may need to be modified. Whether the problem is longstanding, such as asthma, diabetes and epilepsy, or whether there is a history of an important past event such as a thrombosis (eg DVT), specialised, personal advice is needed from a GP as far in advance of pregnancy as possible.
   
• Rubella
  Rubella (German measles) used to be a common childhood illness but most people are now immunised against it. If women catch rubella during pregnancy, especially in the first three months, this can cause malformations in the developing baby.
  Women can have their immunity checked with a blood test before they plan to conceive. If women do need to be immunised, then it is recommended that they should not become pregnant for at least one month following the immunisation.
   
• Genetic counselling
  Women or their partners who have a personal or family history of genetic or chromosomal disorders, such as cystic fibrosis or Down's syndrome, may need to be referred for specialist genetic counselling. Information and advice with regard to future pregnancies can then be tailored to their personal situation.
   
• Misuse of Substances
  Misuse of substances in pregnancy can harm the developing foetus. Always speak to the GP before considering getting pregnant.

Advice for the prospective father

All of the lifestyle advice addressed to women, such as eating healthily, stopping smoking and avoiding excess alcohol is just as relevant to men as their fertility can also be affected by these factors.
Substance misuse can affect the sperm and increase the potential for birth defects.

Men are also advised to wear loose-fitting underwear as excess heat can be harmful to the quality of sperm.