Blood Test Normal Values During Pregnancy in India
Pregnancy changes nearly every parameter in your blood. A haemoglobin of 10.5 that would require investigation in a non-pregnant woman may be within expected range at 28 weeks. A TSH of 3.5 that is perfectly fine normally may be too high in the first trimester. An elevated fasting glucose that is mild outside pregnancy becomes significant when you are pregnant.
This guide covers the major blood tests ordered during antenatal care in India and what the normal ranges look like when you are pregnant.
Complete Blood Count (CBC)
Haemoglobin
| Pregnancy Stage | Haemoglobin (g/dL) |
|---|---|
| First trimester | 11.0 - 14.0 |
| Second trimester | 10.5 - 14.0 |
| Third trimester | 10.0 - 13.0 |
Haemoglobin normally drops during pregnancy - this is called dilutional anaemia and occurs because plasma volume expands more than red cell mass. A haemoglobin of 10.5 at 28 weeks is not necessarily pathological; below 10.0 at any stage warrants iron and B12 assessment.
India has very high rates of anaemia in pregnancy. Even mild anaemia (Hb 10-11) increases risk of preterm birth and low birth weight. Iron supplementation is recommended throughout pregnancy.
Gestational Anaemia Criteria (WHO):
- Below 11.0 g/dL in first trimester: anaemia
- Below 10.5 g/dL in second trimester: anaemia
- Below 11.0 g/dL in third trimester: anaemia
Platelet Count
Normal range is the same as non-pregnant: 1.5-4.0 lakh. However, gestational thrombocytopenia (mild platelet drop to 1.0-1.5 lakh) occurs in about 5-8% of pregnancies in the third trimester and is benign. Platelets below 1.0 lakh in pregnancy require investigation to exclude HELLP syndrome (which carries maternal and foetal risk).
Thyroid Function
Thyroid requirements change dramatically during pregnancy. The foetus cannot produce its own thyroid hormone until about 12 weeks, and depends entirely on maternal T4.
| Trimester | TSH Target |
|---|---|
| First trimester | 0.1 to 2.5 mIU/L |
| Second trimester | 0.2 to 3.0 mIU/L |
| Third trimester | 0.3 to 3.5 mIU/L |
These are tighter than the non-pregnant normal (0.4-4.0 mIU/L). A TSH of 3.0 that is perfectly acceptable normally may be too high in the first trimester.
Women on levothyroxine for hypothyroidism typically need 25-30% dose increases in early pregnancy, often within the first 4-6 weeks after conception. They should contact their endocrinologist as soon as pregnancy is confirmed.
Blood Glucose and Gestational Diabetes
Fasting blood glucose:
- Normal in pregnancy: below 92 mg/dL (more stringent than non-pregnant)
- Gestational diabetes diagnosis: fasting glucose above 92 mg/dL on OGTT
Oral Glucose Tolerance Test (OGTT) in pregnancy: The OGTT (75g glucose) is typically done at 24-28 weeks. India follows WHO/IADPSG criteria:
| Test | Normal | Gestational Diabetes |
|---|---|---|
| Fasting glucose | Below 92 mg/dL | 92 mg/dL or above |
| 1-hour post-glucose | Below 180 mg/dL | 180 mg/dL or above |
| 2-hour post-glucose | Below 153 mg/dL | 153 mg/dL or above |
Any one abnormal value is sufficient for a gestational diabetes diagnosis.
Gestational diabetes affects 10-30% of Indian pregnancies - higher than global averages - due to the population's genetic predisposition to insulin resistance.
Kidney Function
Blood urea and creatinine are lower during pregnancy because blood volume expands and kidneys work harder.
| Marker | Normal (Non-Pregnant) | Normal in Pregnancy |
|---|---|---|
| Creatinine | 0.5 to 1.1 mg/dL | 0.4 to 0.8 mg/dL |
| Blood urea | 7 to 20 mg/dL | 5 to 12 mg/dL |
A creatinine of 0.9 that would be perfectly normal outside pregnancy is on the high side during pregnancy. This matters in pre-eclampsia evaluation.
Urine protein: Even small amounts of protein in urine (above 300 mg/day) during pregnancy are significant and may indicate pre-eclampsia. Routine urine dipstick at every antenatal visit checks for this.
Liver Function
Serum albumin is mildly lower in pregnancy (3.0-3.5 g/dL vs 3.5-5.0 normally) due to haemodilution. ALP is elevated in normal pregnancy because the placenta produces its own ALP. SGPT and SGOT remain normal in uncomplicated pregnancy - if elevated, investigate for obstetric cholestasis or HELLP.
Obstetric cholestasis (intrahepatic cholestasis of pregnancy):
- Severe itching (particularly on palms and soles) in late pregnancy
- Elevated bile acids and raised SGPT/SGOT
- Requires obstetric management - associated with stillbirth risk
Key Tests Specific to Pregnancy in India
- HbA1c: Not used to diagnose gestational diabetes (OGTT is the standard) but useful to distinguish gestational diabetes from pre-existing undetected type 2 diabetes
- Blood group and Rh typing: Rhesus-negative mothers need anti-D immunoglobulin at key points
- TORCH screen: Toxoplasma, rubella, CMV, herpes - often included in early pregnancy workup
Must Read
- Fasting Blood Sugar 100-125: Are You in the Prediabetes Zone? - Fasting glucose ranges in detail - important for gestational diabetes context
- Hemoglobin 10 to 12: Understanding Mild Anaemia - Anaemia is extremely common in Indian pregnancies
Try ReportSense on your own report. ReportSense reads your blood test values in the context of pregnancy - applying pregnancy-specific ranges for TSH, haemoglobin, creatinine, and glucose so you get an accurate picture of what your numbers mean during each trimester. Try it free at reportsense.in.
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