*Thyroid

Question 1

The thyroid gland converts ? into ? and ?

Answer 1

Iodine into T3 and T4

Question 2

What does T3 and T4 do?

Answer 2

Converts oxygen and calories into energy
These hormones play an important role in:
regulation of your weight
energy levels
internal temperature,
skin, hair, nail growth
metabolism

Question 3

What does free T3 and T4 do?

Answer 3

Acts as indicators of thyroid level in the body and stimulates release of TSH when T3/4 levels fall

Question 4

Why is there an increase in dietary iodine requirements in pregnancy?

Answer 4

A rise in the glomerular filtration rate leads to increased renal clearance of iodine.

Iodine is needed for thyroid hormone production.

Fetal levels are dependent on maternal levels

Question 5

*Symptoms - Hypothyroidism

Answer 5

Dry hair
Puffy face
Goiter
Slow heartbeat
Weight gain
Consitpation
If untreated can lead to: miscarraige, PET, FGR, placental abruption, perniatal mortality, neonatal morbidity (impaired neurological development in childhood due to reduced availability of thyroid hormones for fetal requirements)

Question 6

*Symptoms - Hyperthydoidism

Thyrotoxicosis

Answer 6

Hair loss
Mood lability
Memory problems
Bulging eyes
Goitre
Sweating
Tachycardia
Weight loss
Diarrhoea
Muscle pain
Fatigue
Trembling hands
Complications: miscarraige, PET, pre-term labour and birth, IFGR, placental abruption

Question 7

*Management if someone has hypothyroidism

Answer 7

Mgt under care of Endocrinologist / GP
Hypothyroid women - treated with thyroxine. Aiming for TSH <2.5 prior to conception and 1st trimester, TSH <3.0 for 2nd and 3rd trimesters
Increase thryoxine as necessary
Check TFT every 6 weeks
RANZCOG reccomends testing TSH and FT4 in women with type 1 diabetes or thyroid disease

Question 8

*Sources of iodine

Answer 8

Iodine is found mainly in animal protein foods and sea vegetables, and to a lesser extent in fortified foods like breads, cereals, and milk.

Seaweed (nori, kelp, kombu, wakame)
Fish, shellfish (cod, canned tuna, oysters, shrimp)
Table salts labeled “iodized”
Dairy (milk, cheese, yogurt)
Eggs
Beef liver
Chicken
Fortified infant formula

Question 9

Risk factors for thyroid disease

Answer 9

➢ Current or previous thyroid dysfunction (hypo, hyperthyroidism, thyroid surgery and neck irradiation)
➢ Known positive antithyroid antibodies
➢ 30 years of age
➢ Symptoms of thyroid dysfunction and/or goitre
➢ T1DM, coeliac disease, Addisons disease, pernicious anaemia
➢ Family history of thyroid disease
➢ BMI >40
➢ History of miscarriage, infertility or pre-term birth
➢ Recent use of amiodarone, lithium or IV contrast for CT scan

Question 10

What is postpartum thyroiditis?
Symptoms?
Treatment?

Answer 10

• Autoimmune disorder, a form of Hashimoto’s thyroiditis.
• A transient thyroid disorder, characterized by a period of mild hyperthyroidism 1–4 months after the birth of her baby, followed by a phase of hypothyroidism.
• In both phases the disorder presents with fatigue and a painless goitre
• May also mimic postpartum depression.
• Could also affect lactation and milk production

Treatment is not required as recovery is usually spontaneous, but the disorder tends to recur in subsequent pregnancies and may progress to permanent hypothyroidism.

Question 11

Newborn Blood Spot Screening screens for what in relation to the thyroid?
If treatment is started immediately it prevents …

Answer 11

Congenital hypothyroidism
Treatment is started immediately and prevents low IQ and short stature

Question 12

How much iodine do RANZCOG reccomend for all pregnant women, planning a pregnancy or breastfeeding?

Answer 12

Iodine supplement of 150ug which is provided in many pregnancy multis