The Importance of Iron during Pregnancy
Iron is one of the best-known minerals, needed for the production of the red pigments haemoglobin and myoglobin (found in muscle cells). World-wide, iron deficiency is the most common nutritional disease, with most cases going unrecognized.
If you are unable to get sufficient iron from your diet, you may want to consider an iron supplement. As you’ll discover, iron is a vital nutrient, especially during pregnancy. Consult with your doctor to determine whether you should try iron supplements and what your dosage should be.
Why You Need It During Pregnancy
Iron is an essential component of haemoglobin, the red blood cell protein which carries oxygen from the lungs to the tissues. Iron from your diet is also needed to produce your baby’s blood pigment, which is slightly different from yours and known as haemoglobin F (F for fetal). Haemoglobin F binds to oxygen more easily than your own adult haemoglobin, so that oxygen quickly passes from your own bloodstream into your baby’s blood within the placenta. Oxygenated blood arriving from the lacenta and umbilical cord is carried straight up to your baby’s brain to ensure it receives adequate supplies during development. During pregnancy, your iron requirements increase as you produce 30 per cent more red blood cells and haemoglobin.
Many enzyme systems also rely on iron, including those involved in the production of energy from carbohydrate, fat and protein. It also forms part of an antioxidant enzyme system (iron catalase) that is vital for protecting the brain from damage due to exposure to the metabolic chemicals and free radicals produced during the rapid developmental process in the womb. This enzyme may provide some protection against cerebral palsy. Iron also has a role in boosting immunity. White blood cells destroy invading micro-organisms using powerful iron-containing chemicals. In iron deficiency, there is an increased susceptibility to infection, with sufferers being especially prone to recurrent thrush, especially during pregnancy.
A common symptom of iron deficiency during pregnancy is a craving for strange foods such as soil or coal. This is known as pica. If it happens to you during pregnancy, start taking a supplement containing iron immediately – ask your pharmacist or doctor for advice on dosage. Your doctor may also want to perform a blood test to check your iron stores. Long-term deficiency of iron during pregnancy and during childhood can lower your baby’s intelligence.
Iron deficiency increases the risk of growth retardation in the womb and low birthweight. Taking iron supplements during pregnancy may halve the risk of the offspring developing a type of brain tumour (astrocytoma) during childhood.
How Much You Need
Overall, an extra 550 mg of iron is needed throughout pregnancy -300 mg for your baby, 50 mg for the placenta and 200 mg to offset the blood lost during childbirth. As you have stopped having periods while pregnant, however, your iron losses are less than usual. US Recommended Dietary Allowances suggest that iron requirements should double during pregnancy from 15 mg to 30 mg per day. The EC RDA for adults is 14 mg while the UK RNI is 14.8 mg per day. The UK does not suggest any additional iron during pregnancy unless a woman previously had heavy periods (putting her at risk of iron deficiency anaemia). As the average iron intake for British women is only 10.5 mg per day, however (30 per cent lower than recommended) – and as 50 per cent of women obtain less than 9.8 mg per day – a supplement specially formulated for pregnancy and containing some iron is a good idea.
Good Dietary Sources
- brewer’s yeast
- offal (liver, kidney, heart)
- red meat
- fish, especially sardines
- wholemeal bread
- cocoa powder
- egg yolk
- green vegetables
- prunes and other dried fruit
Vegetarian mothers-to-be need to pay special attention to their dietary intake of iron.
The form of iron that is most easily absorbed is organic haem iron found in red meat. Vegetarians, and those who eat little red meat, are therefore at increased risk of iron deficiency. Their intakes are dependent on absorbing inorganic non-haem iron, and food supplements are essential.
Overboiling vegetables decreases their iron availability by up to 20 per cent. Vitamin C increases the absorption of inorganic iron, while calcium- and tannm-containing drinks (such as tea) decrease it. Coffee can reduce iron absorption by up to 39 per cent drunk within an hour of eating. Your absorption of dietary iron generally becomes more efficient during pregnancy, however.
Avoid taking too much iron, as this can cause constipation or indigestion, and excess is toxic. Iron supplements given alone can decrease the absorption of zinc and other essential minerals (such as manganese, chromium and selenium), so some specialists advise that iron should be given in combination with these.