Healthy eating for conception and pregnancy

Eating a healthy diet and being the right body weight is important for men who are hoping to become dads, too. There have been many studies looking at specific nutrients such as zinc and selenium and male sperm quality. However, the key messages for men are:

Optimum weight gain in pregnancy depends on your pre-pregnancy weight. The baby and amniotic fluid are only a small part of the weight gain, the rest is an increase in the mother's fat stores to provide an energy reserve for later breastfeeding. There are no specific recommendations for pregnancy weight gain in the UK. However in the USA, thinner women are encouraged to gain a little more weight, anywhere between 12.8kg and 18kg (28lb to 40lb), while women of an average weight should aim for between 11.5kg and 16kg (25lb to 35lb). Overweight and obese women should aim to gain less weight and this should be discussed with your midwife or health care provider.

In theory, the energy cost of pregnancy is around 77,000 calories. Most of the extra calories are required in the last trimester of pregnancy and are estimated to be around 200kcals extra each day. For some women who become much less active during the last three months of pregnancy, this may mean very little extra food is required, simply because they're not expending as much energy. For women who continue to stay active, a modest snack of a couple of slices of toast with spread and a glass of milk or a yoghurt may be all that's required.

Most people eat more than enough protein so there's no need to increase your protein intake. Try to follow healthy eating principles and include some lean meat, fish or poultry, dairy products, grains, nuts and pulses in your meals.

Most people consume too little fibre. It's particularly important to eat more fibre in pregnancy to avoid the common niggles of constipation and piles (haemorrhoids). Increase your fibre intake by eating lots of fruit and vegetables, wholemeal bread and cereals, brown rice, wholemeal pasta and pulses. You should also drink more, because increasing fibre intake without enough fluids can exacerbate constipation.

This is particularly important before conception and during the first trimester of pregnancy. Mothers who lack sufficient folic acid are at increased risk of having a baby with a neural tube defect (NTD), such as spina bifida.

From the moment you start trying to conceive until the end of week 12 of your pregnancy, you should take a daily 400 microgram supplement of folic acid. Women with a history of NTDs should be prescribed a 5mg supplement.

These supplements should be in addition to dietary intake, which should be about 200 micrograms per day. You can boost your folic acid intake by choosing foods such as:

Folic acid is easily lost during cooking, so steam vegetables or cook in only a little water for a short time to retain as much goodness as possible. Supermarkets and food manufacturers often identify good sources of folic acid with a special label. Look out for these next time you go shopping.

Many women of child-bearing age have low iron stores. Making sure your iron intake is high to top up your iron stores before you get pregnant will help prevent iron deficiency during pregnancy. Your iron levels will be measured throughout pregnancy, and if found to be low you'll be prescribed an iron supplement. Pregnant women should try to maintain a good iron intake from their diet to obtain the other beneficial nutrients in these foods.

Good sources of iron can be split into two categories: meat-based (haem) and plant-based (non-haem). The body doesn't absorb iron from non-meat foods as easily as it does from meat sources. However, you can enhance iron absorption by including a source of vitamin C with your meal. In contrast, tannins found in black tea reduce the absorption. So, it's better to have a glass of orange juice with your bowl of cereal in the morning rather than a cup of tea.

Although liver and liver products, such as paté and liver sausage, are good sources of iron, they can also contain very high concentrations of vitamin A. If taken in excess, this vitamin can build up in the liver and harm an unborn baby.

As a result, the Department of Health advises all pregnant women and those trying to conceive to avoid liver and liver products. You should also be aware that some vitamin supplements and fish liver oil supplements are high in vitamin A, so always choose a specially prepared pregnancy supplement.

To help your body absorb and use iron effectively, you should eat plenty of vitamin C-rich foods. Good sources include citrus fruits (oranges, tangerines, grapefruit and lemons), blackcurrants, strawberries, kiwi fruit, peppers, tomatoes and green leafy vegetables. Aim to eat at least five portions of fruit and vegetables every day.

This is sometimes referred to as the 'sunshine vitamin' because it's made when the skin is exposed to sunlight. Vitamin D is essential for forming and maintaining healthy bones and teeth. It's found in only a few foods, including fortified margarines and reduced-fat spreads, some fortified breakfast cereals, oily fish and meat. A small amount can also be found in milk and eggs.

Current recommendations are that all pregnant women should take a 10 microgram supplement of vitamin D daily. Pregnant and breastfeeding women with dark skin, or those who always cover their skin, are at particular risk of a vitamin D deficiency.

Your requirements of this essential mineral double during pregnancy, and are particularly high during the last ten weeks when calcium is being laid down in your baby's bones. Despite this, no dietary increase is thought necessary because your body adapts to absorb more calcium from foods eaten.

Good sources include milk and dairy foods such as cheese, yoghurt and fromage frais. Pregnant women should aim to have three servings of foods from this group every day - typical servings include a glass of milk, milk with cereal, a small matchbox size chunk of hard cheese or a small pot of yoghurt (125g to 150g). Other sources include bread, green vegetables, canned fish with soft, edible bones (salmon, sardines and pilchards), dried apricots, sesame seeds, tofu, fortified orange juice and fortified soya milk.

Pregnant women should be careful not to expose themselves to the risk of food poisoning, which can be dangerous to the unborn baby, especially in the case of listeriosis and toxoplasmosis.

If you follow the guidelines below, your risk of food poisoning will be low.