Thyroid disorders and anaemia are among the commonest medical conditions in pregnancy in India. Both are easy to test for, both are very treatable, and both matter: an underactive thyroid that is not corrected, and moderate to severe anaemia, are linked with miscarriage, preterm birth, a small baby and heavier bleeding at delivery.
Because tiredness, weight changes, palpitations and breathlessness also happen in normal pregnancy, these conditions are usually picked up on blood tests rather than symptoms. A TSH and a haemoglobin test are therefore part of the first antenatal visit, and haemoglobin is rechecked in each trimester.
Dr. Devang Patel manages thyroid problems and anaemia in pregnancy at Divine Women’s Hospital, Gota, Ahmedabad, as part of routine antenatal care and alongside other high-risk conditions. Doses are adjusted at each visit, so that you reach labour with a normal thyroid level and a healthy haemoglobin.
Why the thyroid matters in pregnancy
The baby depends entirely on the mother’s thyroid hormone for the first 10–12 weeks, before its own thyroid starts working, and this hormone is essential for brain development. Pregnancy also raises the body’s demand for thyroid hormone by about half, so a gland that coped before pregnancy may struggle now.
TSH is the main screening test. In the first trimester, a TSH up to about 2.5–4.0 mIU/L is generally acceptable, depending on the laboratory’s pregnancy-specific range. Free T4 and thyroid peroxidase antibodies (anti-TPO) help decide who needs treatment. Autoimmune thyroiditis (Hashimoto’s) is the commonest cause of an underactive thyroid, and iodised salt remains the main source of iodine in Indian diets.
Types of thyroid problems and how each is managed
| Condition | Typical blood picture | Usual approach |
|---|---|---|
| Overt hypothyroidism | High TSH, low free T4 | Always treated with levothyroxine, started straight away |
| Subclinical hypothyroidism | High TSH, normal free T4 | Often treated, especially if anti-TPO is positive or TSH is clearly raised |
| Anti-TPO positive, normal TSH | Antibodies present, TSH in range | TSH monitored every 4 weeks; treated if it rises |
| Gestational transient thyrotoxicosis | Low TSH, mildly high free T4, often with severe vomiting | Usually settles by 16–20 weeks without antithyroid medicine |
| Graves’ disease | Low TSH, high free T4, TSH-receptor antibodies | Lowest effective dose of antithyroid medicine; baby’s heart rate and growth watched |
Treatment and monitoring for thyroid disease
- Women already on thyroxine usually need about 25–30% more as soon as pregnancy is confirmed; a common practical step is two extra tablets per week until the first TSH result
- TSH is rechecked about every four weeks until 20 weeks, then at least once in the third trimester
- Take thyroxine first thing in the morning on an empty stomach, with water, 30–60 minutes before tea or breakfast
- Keep at least four hours between thyroxine and iron or calcium tablets, which block its absorption
- For hyperthyroidism, propylthiouracil is preferred in the first trimester and carbimazole is often used later, at the lowest dose that keeps free T4 at the upper end of normal
- Do not stop or change your dose on your own; bring recent reports to every visit
Anaemia: why it is so common in India
Anaemia in pregnancy is defined by WHO as a haemoglobin below 11 g/dL. National surveys show that about half of pregnant women in India are anaemic. Blood volume rises by about 40–50% in pregnancy, and the baby and placenta need roughly 1,000 mg of extra iron in total, far more than a typical diet supplies.
Iron deficiency is the commonest cause. Vitamin B12 deficiency is frequent in vegetarian diets, folate deficiency adds to it, and worm infestation, closely spaced pregnancies and heavy periods before pregnancy all contribute. Inherited conditions such as beta-thalassaemia trait, which is not uncommon in Gujarat, also cause small red cells that can mimic iron deficiency.
Signs and tests for anaemia
Mild anaemia often causes no symptoms. As haemoglobin falls, tiredness, breathlessness on climbing stairs, palpitations, headaches, pale skin and nails, hair fall and craving for ice or mud (pica) appear.
- Complete blood count with red cell indices at booking, at 24–28 weeks and around 36 weeks
- Serum ferritin: below 30 µg/L suggests iron deficiency even when haemoglobin is still normal
- Vitamin B12 and folate when the red cells are large or diet is vegetarian
- HPLC (haemoglobin electrophoresis) for thalassaemia trait and other haemoglobin variants, ideally at the first visit
- Partner testing if you carry thalassaemia trait; if both partners are carriers, the baby can be tested by CVS at 11–14 weeks
- Stool examination where worm infestation is suspected, with deworming in the second trimester as per national guidance
Treatment options for anaemia
The choice depends on how low the haemoglobin is, the cause and how many weeks remain before delivery.
| Treatment | When it is used | Points to know |
|---|---|---|
| Preventive iron and folic acid | All pregnant women from the second trimester, continued after birth | One tablet daily under the national Anemia Mukt Bharat programme |
| Treatment-dose oral iron | Mild to moderate iron deficiency | Haemoglobin should rise by about 1 g/dL in 2–4 weeks; take with vitamin C, not with tea or milk |
| Intravenous iron (for example ferric carboxymaltose) | Second or third trimester when tablets fail, are not tolerated, or delivery is near | Given as a short infusion in hospital with monitoring; raises haemoglobin faster |
| Vitamin B12 or folate | Proven deficiency | B12 may be given by injection or tablets; corrects large red cells |
| Blood transfusion | Severe anaemia close to delivery, heavy bleeding or symptoms such as breathlessness at rest | Reserved for specific situations because of its own risks |
Thalassaemia trait is not treated with extra iron unless iron deficiency is also proven, so testing before treatment matters.
Food that helps, the Indian way
Diet alone rarely corrects established anaemia in pregnancy, but it supports treatment and helps prevent recurrence. Vegetarian iron is absorbed less well than iron from meat, so pairing it with vitamin C makes a real difference.
- Green leafy vegetables: methi, palak, sarson, drumstick leaves and amaranth (rajgira) greens
- Pulses and legumes: rajma, chana, moong, masoor and sprouted grains
- Bajra, ragi (nagli) and jowar rotlas in place of some wheat rotli
- Jaggery, dates, dried figs, raisins and roasted chana as snacks
- Lemon, amla, guava or orange with meals to improve absorption
- Eggs, fish or chicken for those who eat them, and dahi or paneer for B12
- Keep tea and coffee at least an hour away from meals and iron tablets
Risks for mother and baby, and how they are reduced
Moderate to severe anaemia is linked with preterm birth, low birth weight and a higher risk of needing a transfusion if there is heavy bleeding after delivery. Anaemic mothers also recover more slowly and find breastfeeding more tiring. Correcting haemoglobin before term, aiming for at least 11 g/dL, is one of the simplest ways to make birth safer.
Untreated overt hypothyroidism is linked with miscarriage, pre-eclampsia, preterm birth and effects on the baby’s development; uncontrolled hyperthyroidism can cause fetal growth problems and, rarely, a thyroid storm. With treatment and regular checks, outcomes are close to those of other pregnancies. At delivery, active management of the third stage and readiness for bleeding are standard for every woman.
After delivery and long-term health
After birth, thyroxine is usually reduced to the pre-pregnancy dose and TSH rechecked at about six weeks. About 5–10% of women develop postpartum thyroiditis in the first year, especially if anti-TPO antibodies were positive; a brief overactive phase is often followed by an underactive one, so unexplained tiredness or low mood after birth deserves a TSH test.
Iron and folic acid tablets are continued for at least three months after delivery to rebuild stores lost in pregnancy and at birth. Spacing the next pregnancy by at least 18 months gives the body time to recover iron, and women with thyroid disease should have a TSH check before trying again.
Your care, step by step
- Baseline testsTSH, haemoglobin, ferritin and, where indicated, free T4, thyroid antibodies, vitamin B12 and HPLC at the first visit.
- Correct earlyThyroxine doses are adjusted and iron started or stepped up as soon as results are back, with clear written instructions.
- Recheck regularlyTSH about every four weeks in early pregnancy and haemoglobin in each trimester, with IV iron arranged in hospital if needed.
- Ready for birthAim for a haemoglobin of at least 11 g/dL before delivery, with 24 × 7 labour and emergency cover at Divine Women’s Hospital.
- After birthThyroxine dose reviewed, TSH at six weeks, and iron continued to rebuild stores.
When to book a visit
- You have hypothyroidism or hyperthyroidism and are pregnant or planning pregnancy
- Your TSH report is above the pregnancy range
- Your haemoglobin is below 11 g/dL, or you feel unusually tired, breathless or dizzy
- You or your partner have thalassaemia trait or a family history of thalassaemia
- Iron tablets cause side effects or your haemoglobin is not improving
- You feel unusually tired, anxious or low in the months after delivery
Warning signs - get same-day care
- Breathlessness at rest or chest pain
- Fainting, or a racing heartbeat that does not settle
- Severe vomiting with inability to keep fluids or tablets down
- Fever, confusion, agitation and a very fast pulse in a woman with hyperthyroidism
- Heavy vaginal bleeding at any stage of pregnancy
- Reduced baby movements
Labour and emergency care are available 24 × 7. Call the hospital and come in directly.
Myths and facts
Myth: Thyroxine is harmful to the baby, so I should stop it in pregnancy.
Levothyroxine is the same hormone your body makes. Stopping it is what harms the baby; most women need a higher dose in pregnancy.
Myth: Iron tablets make the baby’s skin dark.
There is no link between iron tablets and a baby’s complexion. Iron only darkens the mother’s stools.
Myth: Eating more jaggery and spinach is enough to cure anaemia.
Diet helps prevent anaemia, but established anaemia in pregnancy usually needs iron tablets or IV iron.
Myth: Thalassaemia trait is a disease that needs treatment.
Carriers are healthy. The trait matters because, if both partners carry it, the baby could have thalassaemia major, so partner testing is important.
Frequently asked questions
What is the normal TSH level in pregnancy?
In the first trimester, a TSH up to about 2.5–4.0 mIU/L is generally acceptable, depending on the laboratory’s pregnancy-specific range. Values are interpreted with free T4 and thyroid antibodies, and for women already on thyroxine the aim is usually towards the lower end.
Does hypothyroidism affect the baby?
Untreated overt hypothyroidism is linked with miscarriage, preterm birth and effects on the baby’s brain development. When it is treated and TSH is kept within the target range, these risks fall to those of other pregnancies.
Will my baby have a thyroid problem if I have one?
Usually not. Most babies of mothers with hypothyroidism have normal thyroid function. All newborns can have a heel-prick screen for congenital hypothyroidism, and babies of mothers with Graves’ disease are checked more closely after birth.
What is a normal haemoglobin level in pregnancy?
A haemoglobin of 11 g/dL or more is considered normal in pregnancy. Between 10 and 10.9 is mild anaemia, 7 to 9.9 moderate, and below 7 severe.
Is IV iron safe in pregnancy?
Modern intravenous iron preparations are considered safe in the second and third trimesters and raise haemoglobin faster than tablets. They are given in hospital as a short infusion with monitoring for any reaction.
Why do iron tablets cause constipation, and what can I do?
Iron commonly causes constipation, dark stools or nausea. Taking the tablet with a small snack, plenty of water and fibre, or switching to a different preparation usually helps. If you still cannot tolerate tablets, IV iron is an option.
Can I take thyroid and iron tablets together?
No. Iron and calcium reduce the absorption of thyroxine. Take thyroxine first thing on an empty stomach and keep at least four hours before taking iron or calcium.
Should my husband be tested for thalassaemia?
Yes, if your HPLC shows thalassaemia trait. If both partners are carriers, there is a 1 in 4 chance in each pregnancy that the baby has thalassaemia major, and the baby can be tested by CVS at 11–14 weeks.
Can I breastfeed while taking thyroid medicine?
Yes. Levothyroxine is safe in breastfeeding, and antithyroid medicines at usual doses are also compatible with breastfeeding, with the baby’s thyroid checked if doses are high.