TYROTOXICOSIS IN PREGNANCY

Dr Jamali WagimanObstetrician & Gynecologist

Hospital Kuala Lumpur

OVERVIEW

• 2: 1000 Pregnancies• Majority present pre

pregnancy• 0.5:1000 required

treatment.• Severe Thyrotoxicosis

is rare due to underlying unovulatory cycle.

PHYSIOLOGY

• Production of T4 • T3 (70-80%

peripheral conversion)

• TSH and TRH Controlled

• Functions– Energy Production– Protein Synthesis– Growth in Children

T4/T3 SYNTHESISDietary Iodide

OxidizedIodination

Combination

Thyroglobulin(Colloid)

20X

100-200 µg

MIT

DIT

MIT+ DIT = T3

MIT +MIT = T4

T4/T3 SECRETION

Thyroglobulin(Colloid)

T4:T3 (5:1)

TBG

0.05% T4

0.5% T3

HORMONAL CONTROL

• Hypothalamus • Pituitary• Thyroid Gland

TRH

TSH

T3/T4

TREATMENT

Carbimazole

Propylthiourasil

Beta Blocker

Surgery

Radioiodine Therapy.

Synthesis

T4T3

PeripheralConversionMetabolic Effect

FOLLOW UP

7 days1.5 days

T3

T4

Monthly Monitoring of FT4/TSH

Review Symptom

Compliance to Treatment

Initial treatment and remissionStable treatmentStopping TreatmentClinical relapse

EFFECT TO PREGNANCY

• 48% Fetal mortality• 21% Chance of

Thyroid Crisis at Delivery– Confusion– Psychotic– Coma– Tachycardia– Cardiac Arrythmias– Cardiac Failure (5-8%)– Fever

PTUIV IodideDexamethasoneIV PropanololDigoxineDiuretic

Thyroid Storm

GRAVE DISEASE

• 95% Thyrotoxicosis in Pregnancy

• Poor weight gain• Symptomatic

– Exophthalmos– Lid Lag– Palpitation

Autoantibody

T4:T3

Absent of Feedback MechanismAbsent of Feedback Mechanism

GRAVES DISEASE

T3 T4

Y

Y

Y YY

THYROID FUNCTION TEST