Transcript Thyroid Disease in pregnancy

Thyroid Disease in
pregnancy
Introduction
• A number of thyroid disorder are
common in the general population.
• The interaction between pregnancy
and thyroid gland is fascinating;
 There are fundamental changes in
term of tests,
 Intimate relationship between
maternal and fetal thyroid function,
 The drug that affect the mother
thyroid can also affect the fetal
 A number of interaction , abnormal
pregnancy and thyroid conditions??
Introduction
• Endocrine disorders are increasingly
encountered in pregnancy
• To optimize pregnancy outcome, it is
essential to understand the
physiology underlying these
conditions.
• To know which investigations to use
and what kind of treatment is safe in
pregnancy.
• What is the most common endocrine
disorder in women of childbearing?
• What is the second most common?
Fetal Thyroid
• 7-9 weeks formation of thyroid
gland
• 10 weeks
TSH and Thyroxine deteable
• 17 weeks
maturation of the gland
• >18weeks response to TSH stimulation
Thyroid disease in pregnancy
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Hypothrodism
Hyperthroidism
Gestational Thrytoxicosis
Thyrodities
Thyroid storm
Thyroid nodule
Thyroid cancer
Thyroid dysfunction
Hyperthyrodism
• Frequently encountered
• Usually diagnosed prior to
pregnancy
• Symptoms of hyperthroidism are
similar to pregnancy changes;
• Delaying initiation or optimizing
treatment.
• Appropriate ante-natal management,
requires ??
Physiological changes
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Thyroid stimulating hormone (TSH)
Human chorionic Gonadotrophin (hCG)
What similarity between TSH& hCG??
What mimics thyrotoxicosis??
• Changes in pregnancy;
TSH is suppressed
 thyroid binding globulin
Total &Free T3 &T4,
Renal clearance of Iodine
Thyroid hormone and the placenta
Hyperthyroidism
• Incidence; 1:500
• Majority prior to pregnancy
• 90-95% due to Grave's disease
autoimmune
thyroid stimulating antibodies
against TSH receptors
• Other causes of thyrotoxicosis;
toxic nodule
multiple thyroid nodule
Gestational trophoplatic tumour
Grave’s Disease
• Antibodies,
lead to??
cross the placenta and
Abortion, Intrauterine
growth restriction (IUGR)
still birth, fetal tachycardia, premature
labour( Fetal loss)
• Uncontrolled hyperthyroidism
Cardiac arrhythmia, Arterial fibrillation.
Diarrhea, vomiting, abdominal pain and
Psychosis.
Diagnosis
• Symptoms,
increase heart rate
heat intolerance
weight loss
heart murmur
Investigation, TSH,T4&T3,
Diagnosis difficult in pregnancy,
reason??
Management
• Untreated, leads to fetal loss
• Drugs used to maintainT4&T3 to a high /normal range.
• Radioactive Iodine, contraindicated in pregnancy,
effect fetal gland
Medication, to stop synthesis of thyroid hormone
1)
Thioamide; carbimazole 10-40mg( methiazole, aplastic
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Thiourea; propylethiouracil 100-600mg( convertT4 to T3
cutis, embryopathy)
Start with lower does
Large does cross placenta; fetal hypothroidism
10% aplastic leukopenia
cross placenta less readily,
In high doses cause fetal hypothyroidism and goiter
Breast feeding??
Hypothrodism
• Difficulty in conceiving
• Majority on thyroxine prior to
pregnancy
• Incidence is 9/1000 pregnancy
• Risks: fetal loss: abortion, still birth,
premature labour
• In the newborn, congenital cretinism
as a result of congenital hypothyroidism
Etiology
• Primary >95%
• Autoimune thyroditites
• Iodine deficiency, over treated
hyperthyroid, treatment with radio
active Iodine( to avoid this would
should one do?
• Lithium
• Postpatum Haemorrhage Sheehan
syndrome
Diagnosis and mangement
• TSH is ?
• T4 is ?
• Treatment
• Throxine may need to be increased in
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pregnancy to restore TSH to normal
Treatment , throxine 25, 50, 100 ug
Serial TSH, keep it below normal level
Effect of hypothroidism
on pregnancy
• Thyroid hormone are required
for normal mental development.
• Fetus, congenital cretinism
• Infant, diminished school
performance
Postparum
• Postnatal, thyroid dysfunction(10-20%)
and postnatal depression 6-12 weeks after
delivery, initially hyper then hypo