Why do we need iron in pregnancy?
- Iron is needed for the manufacture of haemoglobin in both maternal and foetal red blood cells.
- Lack of iron in pregnancy can lead to Iron Deficiency Anaemia (a condition where you don’t have enough red blood cells; these contain a protein called haemoglobin that carries oxygen around your body and to your baby).
- Iron deficiency in pregnancy can affect the growth and development of the baby and the mother’s health.
- Low iron status in pregnancy is associated with low birthweight and prematurity.
- Latest NDNS (National Diet and Nutrition Survey) shows 10% of women of child bearing age are anaemic.
- In an attempt to prevent deficiency, pregnant women are screened for anaemia at their booking appointment, and again at 28 weeks (if a multiple birth then again at 20-24 weeks).
How much do we need?
- 14.8mg/day (current Dietary Reference Value); this is the same as an adult woman.
- There’s no additional requirement in pregnancy or lactation (there is an increased need for folic acid and vitamin D in pregnancy and routine supplementation is recommended for this, and by virtue of this women also get more iron as the supplements contain iron).
- There is an increased demand for iron in pregnancy, but in theory, this is met through mobilisation of maternal iron stores, savings due to cessation of periods and increased dietary absorption (iron absorption from gastrointestinal tract is increased by as much as 50%).
Does it vary at different times in pregnancy?
There is a higher requirement in the third trimester (the foetus accumulates most of it’s iron during this trimester).
Does it vary from individual to individual?
You will require more iron if carrying twins/triplets.
You are more likely to have anaemia if you’ve had it before, have a history of heavy periods, are pregnant again after having a baby within the last year, are vegetarian or vegan, or are carrying more than 1 baby.
What about after baby is born?
You could be at risk of anaemia depending on blood loss at birth (if >500ml you will have a blood test).
How can you get more of it?
- Eat iron rich foods – 2 servings per day (1 portion meat = 90g, fish portion = 140g).
- Take supplements – the recommended pregnancy supplements contain 17mg iron.
- You can increase absorption of iron from iron rich foods by consuming foods with a high vitamin C content (e.g. kiwi, oranges, having a small orange juice with breakfast).
- Avoid drinking tea and coffee with meals as the tannins in these reduce the ability of the body to absorb iron from foods (pregnant woman shouldn’t have more than 200mg caffeine/day anyway).
Is there such a thing as too much?
Supplements can sometimes lead to side effects such as constipation and nausea.
Research has shown that too much can increase the risk of gestational diabetes, and oxidative stress, which in turn may lead to low birthweight, preterm birth, maternal high blood pressure (preeclampsia) or even miscarriage.
What happens if we don’t have enough?
Mild iron deficiency would lead to symptoms such as feeling more tired and being more susceptible to infection.
Severe deficiency could lead to brittle nails, thinning hair, palpitations, shortness of breath, mouth ulcers, and pale skin.
Iron rich foods and why they are good?
- Animal sources (referred to as Haem iron) are richest in iron and the iron is easiest to absorb (e.g. red meat (beef, lamb, pork). There are lesser amounts of Haem iron found in fish and poultry. In terms of red meat; I would still advise pregnant women to choose lean cuts of meat, trim visible fat off and ideally avoid processed meat products (e.g. sausages).
- Liver is a very rich source of iron, but should be avoided in pregnancy due to risk of vitamin A toxicity.
- Oily fish (e.g. salmon, sardines) is a good source of iron but should be limited to 2 servings per week in pregnancy due to risk of methyl mercury accumulation (portion = 140g).
- Plant sources (referred to as non-haem) include eggs (particularly yolk), pulses (e.g. lentils, peas, baked beans, dhal), nuts, seeds and green leafy vegetables (broccoli, kale, greens, spinach, watercress). Portion of vegetables = 80g. Serving of eggs = 2 (ideally poached, scrambled, boiled rather than fried). Portion of nuts = 50g. Portion of cooked dhal = 250g.
- There is lots of confusion around nuts in pregnancy; the latest advice is that if you wish to eat them then it’s fine (unless you’re allergic to them)!
- Fortified breakfast cereals e.g. Weetabix, Ready brek, Shreddies (these are also good as high fibre foods are recommended to help reduce constipation in pregnancy).
- Wholemeal bread.
- Dried fruit (apricots, raisins, figs, prunes).
Anything different for Vegetarian/Vegan diet?
- Need 3 servings of the non-haem iron rich foods/day.
- Ensure overall diet is high in vitamin C to help improve absorption of iron (peppers, tomatoes).
- Some of the pregnancy supplements won’t be suitable for Vegans (Vegan society make a supplement but this doesn’t have the required folic acid and it doesn’t have iron).
Breakfast ideas: Ready brek, Weetabix or Shreddies with low fat milk
Lunch ideas: Baked beans/scrambled eggs (with wilted spinach)/chicken salad sandwich on wholemeal bread/seeded bread, sardines on toast (wholegrain toast) with tomatoes. Serve with a small glass of orange juice (150ml)
Evening meal ideas: Salmon with broccoli and rice, or chilli con carne (use low fat mince 5-10%), dhal with rice. I also love Chickpea stew with lamb meatballs (packs an iron punch with lamb, chickpeas, spinach). Kiwi fruit and low fat yogurt for dessert.
Snack ideas: hummus with vegetables, small portion of unsalted nuts with dried fruits