What to expect from antenatal care for an underactive thyroid

An underactive thyroid can require closer review during pregnancy because thyroid hormone supports your changing needs. Your team may check thyroid-stimulating hormone and related hormone levels, review symptoms, and adjust prescribed levothyroxine. They can explain how to take it consistently and how to separate it from supplements that may affect absorption. Antenatal appointments also track your blood pressure, wellbeing, baby’s growth and routine pregnancy milestones.

Bring your medicine and supplement list to appointments, including the time you take each product. Take thyroid medicine exactly as prescribed and do not stop it because you feel well. Keep blood-test appointments so changes can be identified promptly. Tell the maternity team about palpitations, unusual tiredness, feeling unusually cold or hot, or a change in symptoms. You can review the wider service in [Antenatal Care Package](/treatments/pregnancy-and-birth-care/antenatal-care-package/).

Contact your maternity service urgently for heavy bleeding, severe abdominal pain, a severe headache with vision changes, chest pain, trouble breathing, fainting, or markedly reduced fetal movement later in pregnancy. Seek prompt advice if vomiting prevents you keeping thyroid medicine down or if you have a sudden, concerning change in symptoms.

Ask how often your thyroid levels will be checked, what result would prompt a dose change, and how to time levothyroxine with iron or calcium supplements. Clarify who will review results and what to do after delivery.