Hyperthyroidism related problems during pregnancy.pdf

Managing thyroid status during the pregnancy is crucial and essential because maternal thyroid status affects the fetus. This presentation which is full of almost all facts you need to know will guide you for better clinical practice. This document is reliable for medical students, nurses, allied health students or even patients or common population will guide you to a better clinical practice. The facts mentioned here are from guidelines. But there may be slight differences in practices in some countries.

1. Hyperthyroidism
during Pregnancy
Sankalpa Gunathilaka
MBBS(UG)
Dip.in Psychology and Counseling

2. Hyperthyroidism
▪1 in 500 pregnancies
Aetiology
•Grave’s disease (95%)
•Solitary toxic adenomas
•Toxic multinodular goitre
•Subacute thyroiditis
•Acute thyroiditis
•Medications (Iodine, Lithium, Amiodarone)

3. Clinical
Features :
•Resembles early normal
pregnancy symptoms:
Heat intolerance,
Palpitation, Tachycardia,
Palmar erythema,
Vomiting, emotional
lability and goiter
Discriminating features:
▪Weight loss
▪Persistent tachycardia
▪Sleeping pulse > 100 per minute
▪Tremor
▪Lig lag
▪Exophthalmos
▪Symptoms predating the pregnancy
Diagnosis:
▪Normal ranges for pregnancy trimesters should be used
for assessment
▪Raised ft4/ft3
▪Reduced TSH

4. Outcome of Hyperthyroidims in Pregnancy if untreated
Maternal Fetal
Tachycardia Miscarriage
Atrial fibrillation Fetal Loss
Heart failure Fetal growth restrictions
Thyroid storm Premature Labour
Increased perinatal mortality
Fetal and neonatal thyrotoxicosis (as thyroid
antibody cross placenta)

5. ❑Antenatal period
▪Medications : Carbimazole, Methimazole, Propylthiouracil(PTU), Beta blockers
▪Aim to achieve rapid optimal control with lowest dose of medications.
▪‘Block and Replace’ thearapy is not recommended.
▪Maintain euthyroid state with free T4 at upper limit of normal range
▪Medication response is delayed and takes 3-4 weeks.Once the response is achieved reduce the dose
gradually to maintenance dose for 12-18 weeks
Carbimazole starting dose 15-40 mg then reduce to 5-15 mg
PTU starting dose 150-300mh then reduce to 50-100 mg
▪For newly diagnosed cases PTU is recommended for first trimester and Carbimazole ince the second
trimester onwards
▪If already diagnosed and under control with Carbimazole since preconception period,it is preferable to
continue low dose Carbimazole.
Management
❑Prepregnancy
▪Avoid conception for 6 months after radioiodine
▪Euthyroid state for 3 months prior to conception

6. ❑Adverse effects
Beta-Blockers
▪Can be used initial 3 weeks of treatment until drug take place.
▪Also reduces the peripheral conversion of T4.
▪Will not cause harmful fetal effects.
Maternal Fetal
PTU can cause liver toxicity in long term use Both can cause congenital abnormalities although
more severe with CBZ
Both PTU and CBZ are associated with
agranulocytosis.(Sore throat should prompt a FBC)
CBZ when used in first trimester can cause rare side
effect-Aplasia cutis of the fetus
Drug urticaria with both drug Fetal Hypothyroidism ( both drugs can cross placenta)
PTU= Propylthiouracil | CBZ= Carbimazole | FBC= Full blood count

7. Postpartum Thyroiditis
•Incidence around 1-17% of pregnancies
•Most common among women with anti thyroid peroxidase antibodies (anti-TPO)
•Usually asymptomatic and present around 3-4 months postpartum
•It can present as either of:
Transient hyperthyroidism
Transient hypothyroidism
Biphasic disease (First hyperthyroidism followed by prolong hypothyroidism)
•Complete recovery in most. But can lead to permenet hypothyroidism(3-4%) and may recur in
future pregnancies(10-25%).
•May need symptomatic treatment with beta blockers but no need of anti thyroid drugs.

8. Thank you !
Good luck for your studies.
(01-06-2024)