Anaemia in Pregnancy: Causes, Iron and Safe Treatment
Medically reviewed by Dr. Priyadatt Patel, MBBS, MS (Obstetrics & Gynaecology) — Senior Gynecologist · Advanced Laparoscopic Surgeon · IVF and Endometriosis Programme Lead, Balaji Horizon Women’s Hospital, Ahmedabad. · Last reviewed: 10 July 2026. Reading time: about 9 minutes. This article is educational and does not replace an individual assessment.
Anaemia in pregnancy is one of the most common conditions an obstetrician sees, and in India it is common enough to be considered the norm rather than the exception. The good news is that the great majority of cases are due to a shortage of iron, are picked up by a simple blood test, and are readily and safely treated. The two mistakes to avoid are opposite ones: ignoring a genuinely low haemoglobin because “everyone is a bit anaemic in pregnancy”, and over-treating a normal mid-pregnancy dip that needs no treatment at all. This article explains where the line sits, what the numbers on your report actually mean, and how anaemia is corrected — through diet, oral iron, and, when needed, intravenous iron — following current WHO and RCOG guidance. For the wider picture, see our pregnancy care overview and our pregnancy nutrition guide.
The short answer
You are considered anaemic in pregnancy when your haemoglobin falls below roughly 11 g/dL in the first and third trimesters, or below 10.5 g/dL in the second trimester. Most pregnancy anaemia is caused by iron deficiency, which is why a serum ferritin test (a measure of iron stores) matters as much as the haemoglobin itself. Iron deficiency is corrected with oral iron in most women, or intravenous iron when tablets are not tolerated, not working, or time before delivery is short. A modest fall in haemoglobin around the middle of pregnancy is often normal and needs no treatment — the aim is to identify and treat true deficiency, not to chase a number.
How common is anaemia in pregnancy in India?
India has one of the highest rates of anaemia in pregnancy in the world. National survey data (NFHS-5, 2019–21) found that about half of pregnant women were anaemic, and the figure is higher in some regions and communities. The commonest reason is dietary iron shortage, made worse by predominantly vegetarian eating patterns (in which iron is less easily absorbed), closely spaced pregnancies, heavy periods before conception, and a starting iron deficit that many women carry into pregnancy. Because it is so common, national programmes such as Anemia Mukt Bharat recommend routine iron and folic acid supplementation for all pregnant women — but routine supplementation does not remove the need to test, because it does not tell you who is truly deficient, how severe it is, or whether a different cause is at work.
Why your haemoglobin naturally dips — physiological versus true anaemia
Pregnancy expands your blood volume substantially. The watery part of the blood (plasma) increases more than the red-cell mass, so the blood becomes more dilute and the haemoglobin concentration falls, typically reaching its lowest point around the late second trimester before recovering. This is sometimes called physiological anaemia or haemodilution, and by itself it is normal, expected, and beneficial — it improves blood flow to the placenta. The clinical skill lies in separating this harmless dilution from genuine iron-deficiency anaemia. That is exactly what the blood tests below are for, and it is why a low haemoglobin is interpreted alongside the red-cell indices and ferritin rather than in isolation. Treating a normal physiological dip with high-dose iron helps no one and simply causes side effects.
Why anaemia in pregnancy matters
Mild anaemia often causes no symptoms at all, or vague ones — tiredness, breathlessness on exertion, dizziness, palpitations, poor concentration, or looking pale. It is worth correcting even when mild, for two practical reasons. First, a woman who begins labour with adequate iron stores tolerates the normal blood loss of delivery far better and is much less likely to need a transfusion. Second, moderate and especially severe anaemia are associated with a higher chance of preterm birth, low birth weight, reduced iron stores in the baby, and, at the severe end, greater risk to the mother. These associations should prompt sensible correction, not alarm: the whole point of routine antenatal blood tests is to find and fix anaemia long before it becomes a problem. Building good iron stores is one of the simplest, highest-value things you can do in an otherwise healthy antenatal course.
The causes — iron, folate, vitamin B12 and beyond
Iron deficiency accounts for the majority of pregnancy anaemia, but it is not the only cause, and this matters when anaemia does not respond as expected to iron:
- Iron deficiency — by far the commonest; the red cells become smaller and paler (low MCV, low MCH).
- Folate deficiency — more likely with poor diet, multiple pregnancy, or certain medications; folate is also given routinely to prevent neural-tube defects.
- Vitamin B12 deficiency — particularly relevant in strict vegetarians and vegans, and worth checking when the cause is unclear.
- Inherited haemoglobin conditions — thalassaemia trait and sickle-cell trait are found in several Indian communities and can cause a low haemoglobin with small red cells that does not respond to iron. Recognising this is important both for the mother and for testing the partner (see below).
- Blood loss and other conditions — heavy periods before pregnancy, recent bleeding, or chronic illness.
Because the treatment differs, the first job is not simply to prescribe iron but to establish which anaemia you have.
How anaemia is diagnosed — the blood tests that matter
Diagnosis is straightforward and non-invasive:
- Full blood count (CBC) — measures the haemoglobin and the red-cell indices. A low MCV (small cells) points towards iron deficiency or a thalassaemia trait; a high MCV points towards folate or B12 deficiency.
- Serum ferritin — the best single marker of iron stores. A ferritin below about 30 µg/L indicates iron deficiency in pregnancy even if the haemoglobin is still in range. One caveat: ferritin rises with infection or inflammation, so it can occasionally read falsely normal — which is why it is interpreted alongside the clinical picture.
- Further tests when indicated — vitamin B12 and folate levels, and a haemoglobinopathy screen (such as HPLC) when a thalassaemia or sickle trait is suspected or the anaemia does not respond to iron.
In most women, a low haemoglobin with a low MCV and low ferritin confirms iron deficiency and treatment can begin at once, without waiting for anything further.
Treating iron-deficiency anaemia — oral iron done right
For most women, oral iron is the first-line treatment and works well. A few practical points make a large difference to whether it is tolerated and absorbed:
- Dose sensibly. A therapeutic dose of elemental iron corrects most iron-deficiency anaemia over several weeks. Emerging evidence suggests that taking iron on alternate days, or as a single daily dose rather than split through the day, can improve absorption and cause fewer side effects — a useful option if tablets upset your stomach.
- Help it absorb. Take iron with a source of vitamin C (a citrus fruit or a glass of lemon water) and away from tea, coffee, milk and calcium supplements, which block absorption.
- Expect a response. The haemoglobin should begin to rise within two to three weeks; your doctor will usually recheck it to confirm the treatment is working.
- Manage side effects. Constipation and nausea are common; alternate-day dosing, taking it with a little food, and adequate fluids and fibre all help. Do not simply stop — tell your doctor so the plan can be adjusted.
Iron and folic acid are also given routinely as prophylaxis in pregnancy; the doses used to treat a diagnosed anaemia are higher and are guided by your blood results.
When intravenous iron or a transfusion is needed
Intravenous (IV) iron is a safe and effective option, generally used from the second trimester onward, when oral iron cannot do the job in time. Typical reasons include genuine intolerance of tablets, poor absorption, an inadequate response, or a moderate-to-severe anaemia discovered later in pregnancy when there is not enough time before delivery for tablets to work. Modern preparations can replace a large amount of iron in one or two short infusions. IV iron is not used in the first trimester and, like any infusion, is given where reactions can be managed.
Blood transfusion is reserved for specific situations — severe symptomatic anaemia, active or heavy bleeding, or anaemia with delivery imminent. It is not a treatment for an asymptomatic low haemoglobin that iron can correct. Keeping transfusion for where it is truly needed is part of good, conservative obstetric care.
Folate, vitamin B12 and the thalassaemia question
When anaemia is not simply iron deficiency, the plan changes. Folate and B12 deficiencies are corrected with the appropriate supplement — important in vegetarian and vegan diets, where B12 in particular can run low. A thalassaemia or sickle-cell trait deserves special mention in the Indian context: if your red cells are small but your iron stores are normal, or your anaemia does not improve with iron, a haemoglobinopathy screen is warranted. If a trait is confirmed, testing the baby’s father is recommended, because when both parents carry a trait there is a risk of a serious inherited condition in the baby that can be identified and discussed early. This is one of the clearest examples of why testing — rather than assuming all anaemia is iron deficiency and simply prescribing iron — genuinely matters.
Iron-rich eating in an Indian diet
Diet supports treatment but rarely reverses an established deficiency on its own — once you are diagnosed anaemic, supplements are usually needed as well. Still, good eating habits help prevent deficiency and maintain stores:
- Iron-containing foods — green leafy vegetables, legumes and dals, whole grains, jaggery, dates, dried fruit, and, for those who eat them, eggs, fish and meat.
- Pair with vitamin C — lemon, amla, guava, citrus and tomatoes with meals substantially improve absorption of iron from plant foods.
- Separate the blockers — tea and coffee with or just after meals markedly reduce iron absorption; keep them well apart from iron-rich meals and iron tablets.
- Vegetarian diets — plant (non-haem) iron is absorbed less efficiently, so vegetarian women are more prone to deficiency and benefit most from testing and, where needed, supplementation.
After delivery — postnatal anaemia
Anaemia does not always end with birth. Blood loss at delivery can lower the haemoglobin further, and postnatal anaemia is linked with greater fatigue, lower mood, and reduced energy for recovery and for feeding the baby — at exactly the time demands are highest. If you were anaemic in pregnancy or bled more than average at delivery, your haemoglobin should be checked afterwards and iron continued as advised. National guidance recommends continuing iron and folic acid for a period after delivery, and this is worth completing rather than stopping the moment the baby arrives.
Anaemia care in Ahmedabad
At Balaji Horizon Women’s Hospital on Science City Road, Ahmedabad, anaemia in pregnancy is screened for routinely, investigated properly when found, and treated in a way that fits each woman — correcting genuine deficiency without over-treating a normal physiological dip. Where oral iron is not enough, intravenous iron is available, and anaemia is followed through to delivery and beyond, including in higher-risk pregnancies where it is part of a wider surveillance plan. If you are pregnant and have been told your haemoglobin is low, a clear explanation of what your numbers mean and a simple plan to correct them is usually all it takes.
When to seek advice
Have your haemoglobin checked as part of routine antenatal care, and speak to your maternity team if you feel persistently tired, breathless, dizzy or notice you are unusually pale. Seek advice promptly if you have been diagnosed anaemic and your tablets are not tolerated or do not seem to be helping, so the plan can be changed. As always, care must be individualised — the details of dose, formulation and monitoring belong to your own doctor and your own blood results.
Frequently asked questions
What haemoglobin level is considered anaemia in pregnancy?
Will iron tablets upset my stomach — and is alternate-day dosing better?
Can I fix pregnancy anaemia through diet alone?
Is intravenous iron safe in pregnancy?
My iron is normal but my haemoglobin is still low — why?
Disclaimer: This article is for educational purposes only and does not replace assessment by a qualified obstetrician. Diagnosis and treatment of anaemia in pregnancy must be individualised to your blood results and clinical situation.
Sources: World Health Organization — Haemoglobin concentrations for the diagnosis of anaemia and guideline on daily iron and folic acid supplementation in pregnant women. Royal College of Obstetricians and Gynaecologists / British Society for Haematology — guidance on the management of iron deficiency in pregnancy. National Family Health Survey (NFHS-5, 2019–21), India. Government of India, Ministry of Health & Family Welfare — Anemia Mukt Bharat programme guidance. Stoffel NU et al., iron absorption with alternate-day dosing, The Lancet Haematology.
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