Anaemia in Pregnancy: and When IV Iron Makes Sense

Anaemia means the blood is carrying less haemoglobin than it should, so less oxygen reaches you and your baby. In India it is not an occasional finding in pregnancy — it is the norm. According to the latest National Family Health Survey, 52.2% of pregnant women are anaemic, up from 50.4% in the survey before.

It is also one of the most fixable problems in pregnancy, provided it is caught early, the cause is actually identified, and treatment is chosen for the woman in front of you rather than handed out as a default.

Why it matters

Mild anaemia causes tiredness, breathlessness on stairs and a feeling of never quite recovering. That alone is worth fixing. But the bigger reason is what happens at the end of pregnancy.

Every delivery involves some blood loss, and a few involve a lot. A woman with a healthy haemoglobin can lose a significant amount and recover; a woman who starts labour already anaemic has much less margin, is more likely to need a transfusion, and recovers more slowly afterwards — at exactly the time she is also feeding and caring for a newborn. Anaemia in pregnancy is also associated with low birth weight and early delivery. Treating it is not cosmetic.

The numbers on your report

Haemoglobin naturally dips a little in the middle of pregnancy because the blood volume expands faster than the red cells. That is why a slightly low reading in the second trimester is interpreted differently from the same reading at term.

A number is not a diagnosis

This is where a lot of care goes wrong. The report says "Hb 9.2", iron tablets are started, and nobody asks why. In India there are several common reasons, and they need different treatment:

• Iron deficiency — the commonest. Confirmed by a low ferritin, the measure of the body's iron stores. A ferritin below about 30 is generally taken to mean the stores are depleted.
• Vitamin B12 or folate deficiency — particularly in women on vegetarian diets. Iron will not correct it.
• Thalassaemia trait — an inherited change that makes red cells small. Carriers are usually healthy, but their blood count can look like iron deficiency, and giving iron to someone who is not iron-deficient does not help. It also matters for the baby: if both parents carry the trait, the baby can inherit thalassaemia major, which is why the father is tested too.
• Blood loss, infection or worm infestation in some women.

So the useful first tests are a complete blood count with the red-cell indices, a ferritin, and where the picture suggests it, a B12 level and a test for thalassaemia trait. All of these are blood tests done at the clinic.

Iron tablets: why they often fail

Iron and folic acid tablets are given to every pregnant woman under India's national programme, and for many they work well. When they fail, it is usually for one of these reasons:

• They are not taken. Nausea, heartburn, constipation and stomach cramps are common, and women quietly stop. Tell your doctor — changing the preparation, the timing or the schedule often fixes it.
• They are taken with tea, coffee or milk. These block iron absorption. Take iron with water or with something containing vitamin C, like a glass of lemon water or an orange, and keep tea and coffee at least an hour away.
• They are taken with calcium. Calcium and iron compete. Take them at different times of day.
• The anaemia is not caused by iron deficiency in the first place — see the section above.
• There is not enough time. Tablets raise haemoglobin slowly. If anaemia is found late in pregnancy, tablets may simply not have time to work before delivery.

Dark or black stools on iron are normal and harmless. Iron does not make the baby "too big", and it does not harm the baby.

When an iron infusion makes sense

Intravenous iron delivers iron directly into the bloodstream. Modern preparations can replace a large proportion of the missing iron in one or two sittings, and they avoid the stomach side effects of tablets entirely. India's national anaemia programme includes intravenous iron for pregnant women with moderate and severe anaemia, and a large Indian trial, RAPIDIRON, was set up specifically to compare it with tablets.

It is not for everyone. It is not used when the anaemia is not caused by iron deficiency, in the first trimester, or in women with a history of reactions to intravenous iron. Serious allergic reactions are rare with modern preparations, but they can happen, which is why the infusion is given slowly, with monitoring, and with the ability to respond immediately.

What it involves: a small cannula in the arm, a drip that usually runs for a short time depending on the preparation, and a period of observation afterwards. You go home the same day. Haemoglobin is rechecked after a few weeks, because it takes time for new red cells to be made.

When a transfusion is needed

A blood transfusion is reserved for severe anaemia, particularly close to delivery, or for heavy bleeding. It is given at hospital. Treating anaemia early is largely about making sure a transfusion never becomes necessary.

Food helps, but it will not fix established anaemia

Iron-rich foods — green leafy vegetables, pulses, eggs, meat, fish, jaggery, dates — are worth eating, and our page on foods in pregnancy covers them. But diet alone rarely corrects anaemia once it is established. Iron from plant foods is poorly absorbed, and the amounts involved are small compared with what a depleted pregnant woman needs. Food is support, not treatment.

After delivery

Anaemia often gets worse after the birth because of blood loss, and it is one of the causes of the exhaustion many new mothers put down to lack of sleep. It is worth a haemoglobin check before you go home and continuing treatment afterwards — and it is worth sorting out before the next pregnancy, which our page on preparing for pregnancy covers.

What happens at the clinic

Blood tests — complete blood count, ferritin, B12 and thalassaemia screening — are done at the clinic, along with your antenatal care and prescribing. Intravenous iron can be given at the clinic where it is appropriate, with observation afterwards. Blood transfusion and delivery happen at hospital, and scans are arranged by referral, as are all scans.

If you have been on iron tablets for weeks and your haemoglobin has not moved, bring your reports. That is the most useful single conversation to have.