What nutrients and supplements do you and your baby need during each trimester?

First trimester (up to 14 weeks)

How is my baby developing?

During the second week a dark mark appears - it will be the spinal cord. By the end of the third week your embryo has a heart that's now beginning to beat, and the developing umbilical cord begins to channel vital nutrients from your body to your embryo in week five. Shortly after, the kidneys and liver begin to take shape and the basic parts of the eye and the brain are forming. Fingers and toes are recognizable at 10 weeks as are the bones, teeth, nails and intestines. The neural tube, which will become the baby's spinal cord, is also being formed.

What you need

Ideally you should start taking 400 mcg of folic acid per day three months before conceiving or, as soon as you confirm your pregnancy. Continue taking daily folic acid to the end of your first trimester. It's available over the counter from the pharmacy and can dramatically reduce the risk of spina bifida, a rare abnormality where the neural tube doesn't close properly.

Taking care to eat a healthy diet should provide pregnant women and their developing babies with all the nourishment required for optimum health. However, according to a recent study carried out by scientists at St. Thomas's Hospital in London, four out of 10 pregnant women need to supplement their diets with multi-vitamin and mineral supplements including iron and vitamin D. Be sure to consult your doctor first as you should never take any supplements or over the counter medications without medical supervision.

Second trimester (up to 26 weeks)

How is my baby developing?

At 18 weeks the eyelids have formed but are fused shut and won't open till the sixth month. Fingernails are clearly visible. The lungs are developing and "breathing" movements can be seen. All the major organs are starting to work and the sex organs are forming. Taste buds are developing on the tongue and the ears can hear sounds. The membranes of the brain and the retina of the eye begin to grow during the second trimester. By the end, the brain's cortex, the most elaborate structure in the animal kingdom, is starting to develop into layers. Your baby's heartbeat can be easily picked up by a stethoscope and you start to feel your baby's limb movements. By six months your baby's face is very like that of a newborn baby.

What you need

DHA is a major structural long-chain fatty acid in the grey matter of the brain and the retina of the eye. Dietary sources of DHA include:

  • Fatty fish including anchovies, salmon, herring, mackerel, tuna and halibut 
  • Fish oil 
  • Organ meat such as liver 
  • Small amounts are found in poultry and egg yolks 
  • Walnuts and flaxseed oil are actually sources of another omega-3 fatty acid, alpha-linolenic acid, or ALA, which the human body can convert to DHA, though slowly and unpredictably
  • Algae - Certain algae are natural sources of DHA. While most people believe that fish produce their own DHA, it’s the algae they feed on that make them a rich source of DHA.

Third trimester (up to term)

How is my baby developing?

The nostrils are starting to open as are the eyelids. Your baby is gaining weight at a startling rate, putting on fat all over the body and doubling its weight between week 33 and 40.

The brain becomes wrinkly in appearance, giving more space for more brain cells. By birth, your baby's brain will contain billions of nerve cells - many of which are produced during these vital final months of pregnancy. Very few more will be formed during your baby's lifetime. During this period, all five senses, including sight and hearing develop sufficiently so that they can function immediately after birth. Because of this tremendous brain growth, the baby's head circumference increases by nearly 1.3 centimetres or half an inch every week at this stage.

What you need

Remember that your baby can only take nutrients directly from you to build up internal stores. A healthy diet becomes increasingly important in this trimester - including eating plenty of dairy and broccoli as a source of calcium for your baby's bones, iron from iron-rich foods like leafy vegetables and red meat and protein for healthy cell growth. Foods containing the omega-3 fatty acid DHA are also important later pregnancy and during breastfeeding.

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