Pregnancy Thyroid Problems

Question 1

What thyroid hormone changes occur during pregnancy?

Answer 1

• increase in levels of thyroxine-binding globulin (TBG)

=> increase in the levels of total T4 but does not affect the free T4 level

Question 2

What complications can be caused by untreated thyrotoxicosis in pregnancy?

Answer 2

Increased risk of risk of:
- fetal loss
- maternal heart failure
- premature labour

Question 3

What is the most common cause of thyrotoxicosis in pregnancy?

Answer 3

Graves’ disease

Question 4

Management of thyrotoxicosis in pregnancy

Answer 4

Propylthiouracil - 1st trimester

Carbimazole - 2nd/3rd trimester

radioiodine contraindicated

Question 5

Why should maternal free T4 levels be kept in the upper third of the normal reference range?

Answer 5

to avoid fetal hypothyroidism

Question 6

At what gestation should thyrotrophin receptor stimulating antibodies be checked to determine the risk of neonatal thyroid problems?

Answer 6

30-36 weeks

Question 7

Levothyroxine is safe to take during pregnancy and breastfeeding. TRUE/FALSE?

Answer 7

TRUE

Question 8

When should TFTs be measured in pregnancy?

Answer 8

• in each trimester
• 6-8 weeks post-partum

Question 9

By how much should a woman’s levothyroxine dose be increased during pregnancy?

Answer 9

by up to 50% as early as 4-6 weeks of pregnancy