Third trimester — antenatal tests

Third trimester — antenatal tests

• HemoglobinHemoglobin measures the protein in red blood cells that carries oxygen. It supplies oxygen to your body and to your baby.
• TSHTSH (Thyroid-Stimulating Hormone) is a hormone from the pituitary gland in your brain. It controls how much thyroid hormone your thyroid gland makes.
• Free T4 (FT4)Free T4 is the active, unbound form of thyroxine. Thyroxine is the main hormone your thyroid gland makes.
• FerritinFerritin is a protein that stores iron in your cells and tissues. Its blood level reflects the total iron reserves in your body.
• Platelet CountPlatelet count measures the number of tiny blood cells called platelets. Platelets help your blood clot and stop bleeding.
• Urine Routine & ProteinThe urine routine examination checks a urine sample for protein, glucose, blood, white cells, and other parts. The protein check looks at whether your kidneys are leaking protein.

Tests by trimester

• First trimester
• Second trimester
• Third trimester

Frequently asked questions

Which blood tests happen in the third trimester?

In the third trimester, antenatal care commonly includes Hemoglobin, TSH, Free T4 (FT4), Ferritin, Platelet Count, Urine Routine & Protein. The exact tests and timing are decided by your obstetrician [WHO, 2016].

Are the reference ranges different in the third trimester?

For some tests, yes — thyroid and glucose in particular are read against pregnancy- or trimester-specific ranges [ATA, 2017]. Each test page names its source where trimester-specific data exists.

What should I do with a result in the third trimester?

Bring the full report to your obstetrician, who interprets each value for your specific pregnancy. Antenatal results are always discussed with them rather than acted on alone.

Why are anaemia and gestational diabetes checked in pregnancy?

They are common and manageable, and antenatal testing is designed to catch them early so your obstetrician can guide next steps.