Anaemia in Early Pregnancy: A UK Guide
What is anaemia in pregnancy?
Anaemia means you have fewer red blood cells or lower haemoglobin than normal. Red cells carry oxygen around your body, so when they fall, you feel tired, weak and short of breath. Anaemia is the most common blood condition in UK pregnancy, affecting around 1 in 4 women at some point. Iron-deficiency anaemia is by far the most common type, but folate and B12 deficiencies also occur.
Why pregnancy increases the risk
During pregnancy your blood volume expands by up to 50% to support your baby. This increase dilutes the concentration of red cells, so your haemoglobin naturally falls slightly. At the same time, your baby draws iron from your stores, especially in the second and third trimesters. If your iron intake does not keep up, you can become anaemic.
Symptoms of anaemia
Early signs can be subtle and overlap with normal pregnancy tiredness. Watch for:
- Persistent exhaustion beyond what you would expect
- Pale skin, lips or inner eyelids
- Shortness of breath on gentle activity
- Dizziness or lightheadedness
- Headaches
- Fast or irregular heartbeat
- Cold hands and feet
- Cravings for non-food items (pica), such as ice or chalk
Severe anaemia can increase the risk of premature birth, low birth weight and a harder recovery after delivery.
How it is diagnosed
Anaemia is diagnosed with a full blood count (FBC) taken at your booking appointment and again at around 28 weeks. In the UK:
- Haemoglobin below 110g/L in early pregnancy is usually classified as anaemia
- Below 105g/L later in pregnancy may also be treated
Your midwife may also check ferritin (iron stores), B12 and folate levels to find the cause.
Causes of anaemia in pregnancy
- Iron deficiency - the most common cause, often due to diet and baby's demands
- Folate deficiency - less common now with folic acid supplementation, but possible
- Vitamin B12 deficiency - more common in vegan or vegetarian diets
- Blood loss - from heavy periods before pregnancy, bleeding in pregnancy, or a previous miscarriage
- Inherited conditions - sickle cell trait or thalassaemia (screened at booking)
Treatment options
Iron tablets
Most women are prescribed oral iron such as ferrous sulphate or ferrous fumarate. Tips for taking iron:
- Take with vitamin C (e.g. orange juice) to boost absorption
- Avoid taking with tea, coffee or calcium (including milk and antacids)
- Space iron at least 2 hours from thyroid tablets or certain antibiotics
- Side effects include constipation and dark stools - normal, but tell your midwife if severe
Dietary changes
Iron-rich foods include:
- Red meat, poultry and fish
- Lentils, beans and chickpeas
- Dark green leafy vegetables such as spinach and kale
- Fortified breakfast cereals
- Dried fruit such as apricots and figs
Pair plant-based iron with vitamin C sources to improve absorption.
Iron infusions
If tablets do not work, cause severe side effects, or your anaemia is severe, your hospital may offer an intravenous iron infusion. This is done as an outpatient and can lift iron levels quickly.
B12 or folate deficiency
These are treated with vitamin supplements - tablets or, for B12, sometimes injections.
Preventing anaemia
Anaemia in pregnancy is common and usually responds well to simple treatment. Left unchecked, it drains your energy and can affect your baby's growth. If you feel unusually tired or breathless, ask your midwife for a blood test - it is quick, safe and can make a real difference.