First Trimester: The first three months of your pregnancy
Weeks 1-4
Folic acid is essential during this period, and ideally should be taken for six weeks before you conceive. In the first 28 days of pregnancy, there's lots of cell division in the embryo, and neural tubes are developing.
Folic acid reduces the risks of spina bifida, birth defects, miscarriage and low birth weight. You should take a supplement of at least 400mcg daily throughout your pregnancy, as it's difficult to get enough from food alone.
During these early days, the inner-layer cells of the embryo will become your baby, and the outer layer of cells the placenta. Research shows that the growth of the placenta is directly linked with the mum's food intake and that a healthy, well-nourished woman builds a better placenta.
The placenta is the nutrition highway between you and your baby, so ensure your diet is packed with nutrient-dense fresh and unprocessed foods.
If you haven't already, now is the time to cut out all the nutrient-zappers such as alcohol, cigarettes and caffeine, as toxins from these can pass through the placenta to your baby.
Weeks 5-12
During the second month, you may start to experience nausea and food aversions or cravings. Trust your instinct on this, as you may just be hankering after what your baby needs, eg, steak=iron, or milk=calcium.
You can help reduce the effects of morning sickness by increasing your levels of zinc and vitamin B6. Sip ginger tea and snack on nuts and seeds.
Feeling exhausted is a major complaint during this time, and it's not surprising with all that's going on inside you. To ease this feeling of fatigue, choose energy-givers rather than energy-sappers.
Switch from all white refined foods such as bread, rice and pasta to wholemeal bread, brown rice and wholemeal pasta, as these help to balance blood-sugar levels. Avoid sugary foods and caffeinated drinks, and try to eat every four hours. Drink plenty of fluids, including water and fresh vegetable juices. And take that afternoon nap when you can.
Second trimester: The second three months of your pregnancy
Weeks 13-16
While the first 12 weeks focus mainly on developing organs, skeleton, tissue and cells, this trimester concentrates on your baby's rapid growth. Aim to eat around 300 extra calories each day to support this - that's the equivalent of an apple, a piece of wholemeal toast and a glass of milk. You may be averaging a weight gain of around 1/2-1lb a week.
You can suffer from constipation at any time in pregnancy, as hormones slow down the movement of food in your intestines, to allow more absorption from the food. But as your baby starts to grow during this trimester, she may begin to put pressure on your intestines.
To help move things along, eat plenty of fibrous foods, drink at least eight glasses of water a day, take up gentle exercise such as swimming or walking and avoid caffeine as it dehydrates the body further. If all this fails, soak a dessert spoonful of linseeds in water overnight and drink the liquid every morning until the symptoms have passed.
Weeks 16-24
Your baby's senses are developing now. Hearing develops at 16 weeks, although the ear isn't fully formed until the 24th week, and towards the end of this trimester her eyes begin to open.
Vitamin A plays an important role in visual and hearing development. Vegetable sources of vitamin A, called betacarotene, are the safest. So add carrots and yellow peppers to the menu.
Weeks 24-28
Towards the end of the second trimester, your enlarged uterus takes up space usually occupied by the digestive system, and may push against your stomach. This could be why almost 80% of pregnant women suffer heartburn.
Normally, foods are mixed with gastric acids in the stomach and move on down to the intestines. With the pressure of the baby, however, this acidic mix can move up the oesophagus instead, causing a burning feeling in your chest.
To avoid further aggravation, eat smaller, more frequent meals, avoid spicy or fatty foods, carbonated drinks, processed meats, alcohol and coffee.
Try to eat at least three hours before bedtime and chew slowly. It's a good idea to sleep with your head raised, as this helps prevent the digested contents of your stomach from moving up towards the oesophagus.
Third trimester: The last three months of your pregnancy
Weeks 29-34
You're now transferring even more essential fatty acids for your baby's developing brain, more calcium for bones and teeth and more iron to protect against anaemia after birth.
It's important during this trimester to continue to eat a highly nutritious diet; otherwise the body transfers all its stores to the baby, leaving you feeling exhausted. Put oily fish, nuts, seeds, lean red meat, pulses, dark green leafy veg and natural yogurt on the menu.
During this time your baby will double in size and will demand more calories from you. So you should continue to eat around 300 extra calories each day. A steady weight gain is essential, as too little may mean that your baby risks being premature. But gaining too much weight is not advisable, either. This is the time when fat cells are laid down and too much excess fat from you could mean that your baby may battle with weight problems for life.
Beware of hidden fats in cakes and biscuits, and remember that sugar turns to fat. So when you snack, it's best to opt for fresh fruit, nuts, seeds and healthy cereal bars.
Weeks 35-40
Giving birth has been compared to running a marathon in terms of energy requirements. Prepare two weeks before you're due by stocking up on complex carbohydrates such as whole grains, vegetables and wholemeal breads, as these are the body's main energy source.
By the end of this trimester your baby weighs about 7lb 5oz, but you may have gained around 28lb. Don't worry! Most of it is fluid, increased blood volume and placenta. Excess fat is needed in preparation for breastfeeding - the best start your baby can have in life.
Note: Check with your GP or midwife before you make any changes to your diet or exercise programmes. Any supplements should be monitored and supervised by your GP, midwife or a qualified nutritional therapist.
