2. Contents
• Anatomy
• Physiology
• Changes in thyroid physiology in pregnancy
• Hyperthyroidism in pregnancy
• Hypothyroidism in pregnancy
• Management
• Screening in pregnant women
• Postpartum thyroiditis
• Thyroid nodules and pregnancy
3. Anatomy
• The thyroid gland is
anterior in the neck
below and lateral to the
thyroid cartilage.
• It consists of
– Two lateral lobes
– Isthmus
Richard F .Thyroid anatomy In GRAY’S Anatomy, third edition , Elseveir,
uk , 2015
13. Regulation of thyroid hormone
secretion
Kim E. Thyroid Physiology In Ganong’ Review of Medica Physiology, 24th edition, New
14. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Graw Hill , 2014 pp 1147.
Changes in Pregnancy
• Physiological changes of pregnancy cause the thyroid
gland to increase production of thyroid hormones by 40
to 100 percent to meet maternal and fetal needs.
• mean thyroid volume increased from 12 mL in the first
trimester to 15 mL at delivery pregnancy-induced
changes.
• TRH levels are not increased during normal pregnancy.
• Due to beta-hcg, initially TSH level decrease in
pregnancy, which give false report of subclinical
hypothyroidism.
15. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Graw Hill , 2014 pp 1147.
16. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Graw Hill , 2014 pp 1147.
17. Hyperthyroidism
• Hyperthyroidism affects 0.2 % of pregnant
women and 95% of these will have diagnosis
of Grave’s disease .
• The incidence of thyrotoxicosis or
hyperthyroidism in pregnancy is varied
and complicates between 2 and 17 per
1000 births when gestational-age
appropriate TSH threshold values are used.
18. Graves disease
• Graves' disease, also known as toxic
diffuse goiter is an autoimmune disease
that affects the thyroid.
• A long-acting thyroid stimulator (LATS),
distinct from pituitary thyrotropin (TSH), is
found in the serum of some patients with
Graves' disease.
• Graves' hyperthyroidism was found to
contain a long-acting thyroid stimulator
(LATS)
21. James, Steer, Weiner.Thyroid disease: in High risk pregnancy management
option, fourth
edition, uk , elsevier, 2006 pp 813-829.
Clinical features
• Suggestive findings include tachycardia
that exceeds that usually seen with
normal pregnancy, thyromegaly,
exophthalmos, and failure to gain weight
despite adequate food intake.
• Diagnosing hyperthyroidism in
pregnancy may be difficult.
• Some time associated with Hyperemesis.
early
22. Maternal effect
• Prepregnacy
– Infertility
• 1st trimester
– Miscarriage
– Hyperemesis
• Second and third trimester
– Heart failure
– Preeclampsia
– Adverse perinatal outcome- perinatal mortality
rate is 6- 12%.(IUGR, placental abruption, still
birth)
James, Steer, Weiner.Thyroid disease: in High risk pregnancy management option,
23. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Graw Hill , 2014 pp 1147.
26. Diagnosis
Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Graw Hill , 2014 pp 1147.
Thyrotoxicosis usually presents in the late first or early second trimester.
• Symptoms are as for thyrotoxicosis outside pregnancy, but these may be
unhelpful and commonly reported by many euthyroid pregnant women (e.g.,
palmar erythema, emotional lability, vomiting, goiter. and heat intolerance).
• Discriminatory symptoms may be weight loss, tremor, lid lag, lid retraction. and
a persistent tachycardia greater than 100 beats/min. • Diagnosing
hyperthyroidism in early pregnancy may be difficult.
• The diagnosis of hyperthyroidism is confirmed by an elevated free T4 and/or
free T3 with suppressed TSH levels.
27. Therapeutic modalities for hyperthyroidism
Therapeutic modalities for hyperthyroidism can be divided into five
categories
• Thionamides (propylthiouracil, carbimazole, methimazole)- Prevent
conversion of T4 to T3 and reduces the peroxidase function and block
coupling of the idotyrosine.
• β-Blockers-Decrease palpitation as well as reduces the peripheral
conversion of T4 to T3.
• Iodides
• Radioactive iodine
• Surgery.
James, Steer, Weiner.Thyroid disease: in High risk pregnancy
management option, fourth edition,uk , elsevier, 2006 pp 813-829.
30. Thyroid Storm and Heart Failure
• Both are acute and life-threatening in
pregnancy.
• Thyroid storm is a hypermetabolic state
and is rare in pregnancy.
• In these women, cardiomyopathy is
characterized by a high-output state, which
may lead to a dilated cardiomyopathy.
• Heart failure develops in 8% of the patient
with uncontrolled hyperthyroidism.
Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New York,
Mac
Graw Hill , 2014 pp 1147.
32. Hypothyroidism
• Hypothyroidism affects 1% of pregnant
women, and as with hyperthyroidism,
many of the symptoms are encountered
in normal pregnancy.
• 2 and 10 pregnancies per 1000.
33. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Graw Hill , 2014 pp 1147.
34. Causes
• Autoimmune (hashimoto
thyroiditis)
• Iatrogenic (lithium, amiodarone )
• Transient(de Quervain’s thyroiditis
or postpartum thyroiditis)
James, Steer, Weiner.Thyroid disease: in High risk pregnancy management option, fourth
edition, uk , elsevier, 2006 pp 813-829.
35. Clinical
features
• Fatigue
• Constipation
• Cold
intolerance
• Muscle
cramps
• Weight gain
Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Graw Hill , 2014 pp 1147.
36. James, Steer, Weiner.Thyroid disease: in High risk pregnancy management option, fourth
edition,
Diagnosis
• Hypothyroidism may be diagnosed in
those with a reduced free T4
concentration in association with an
elevated TSH, which outside pregnancy, is
a sensitive indicator of the degree of
thyroid hormone deficiency.
• Identifying TPO autoantibodies can
confirm the diagnosis, but these are
nonspecific, being present in 20% to 30%
of the normal population.
37. Maternal effect
• Myxoedema coma -extremely rare
in pregnancy, but it represents a
true medical emergency with a
20% mortality rate.
• The clinical picture of myxedema
coma includes hypothermia,
bradycardia, decreased deep
tendon reflexes, and altered
consciousness.
• Hyponatremia,hypoglycemia,
hypoxia, and hypercapnia may also
be present.
James, Steer, Weiner.Thyroid disease: in High risk pregnancy management option, fourth
edition,
38. Maternal effect
Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac Graw Hill , 2014 pp 1147.
39. Fetal effect
• Low IQ Level
• Crentinism
• Neonatal or
fetal
hypothyroidism
• Congenital absence of
the thyroid gland
James, Steer, Weiner.Thyroid disease: in High risk pregnancy management option, fourth
edition, uk , elsevier, 2006 pp 813-829.
41. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Subclinical hypothyroidism
• If normal thyroid hormone level but elevated
TSH level.
• This thyroid condition is common in women,
but its incidence can be variable depending
on age, race, dietary iodine intake, and
serum TSH thresholds used to establish the
diagnosis.
• its prevalence in pregnancy has been
estimated to be between 2 and 5 percent.
• 17% of subclinical hypothyroid women will
develop hypothyroidism in next 20 years.
43. TSH Level Screening in
Pregnancy
• The American College of Obstetricians and Gynecologists
(2013) has reaffirmed that although observational data
were consistent with the possibility that subclinical
hypothyroidism was associated with adverse
neuropsychological development, there have been no
interventional trials to demonstrate improvement.
• College thus has consistently recommended against
implementation of screening until further studies are done
to validate or refute these findings.
• The American Thyroid Association, and the American
Association of Clinical Endocrinologists now uniformly
recommend screening only those at increased risk
during pregnancy
Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New York,
Mac Graw Hill , 2014 pp 1147.
44. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Isolated Maternal
Hypothyroxinemia
• Women with low serum free T4 values but a normal
range TSH level are considered to have isolated
maternal hypothyroxinemia.
• 2.1-percent incidence in the FASTER Trial.
• Offspring of women with isolated hypothyroxinemia
have been reported to have neurodevelopmental
difficulties at age 3 weeks, 10 months, and 2 years.
• CATS study did not find improved
neurodevelopmental outcomes in women with
isolated hypothyroxinemia who were then treated
with thyroxine.
• Because of this, routine screening for isolated
hypothyroxinemia is not recommended.
45. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Postpartum thyroiditis
• Transient autoimmune thyroiditis is
consistently found in approximately 5 to 10
percent of women during the first year after
childbirth.
• Postpartum thyroid dysfunction with an
onset within 12 months includes
hyperthyroidism, hypothyroidism, or both.
• Up to 50 percent of women who are
thyroid- antibody positive in the first
trimester will develop postpartum
thyroiditis.
46. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
Nodular Thyroid
Disease
• Thyroid nodules can be found in 1 to 2
percent of reproductiveaged women.
• Management of a palpable thyroid nodule
during pregnancy depends on gestational
age and mass size.
• An important consideration is that,
although rare overall,90% of thyroid
cancers present as thyroid nodules.
47. Cunninghams . Endocrine disorders: In Williams Obstetrics, 24th Edition, New
York, Mac
• Carcinomas derived from thyroid
epithelium may be papillary, follicular
(differentiated), or undifferentiated.
• Only those nodules thought to be
malignant need further investigation or
treatment, which is usually by surgery with
or without radioiodine.
48. James, Steer, Weiner.Thyroid disease: in High risk pregnancy management option, fourth
edition,
Diagnosis
• Outside pregnancy, radioiodine is used to
distinguish “cold” (more likely to be
malignant) from “hot” (functioning)
nodules. Which is contraindicated in
pregnancy.
• Ultrasound, therefore, forms the
main investigative tool.
• Fine-needle aspiration should be reserved
for rapidly enlarging nodules, cystic
nodules larger than 4 cm or solid nodules
larger than 2 cm.55
50. Take home
message
• Thyroid disorder is common in general
population as well as common in pregnant
mother.
• By treating and preventing thyroid
condition we can preserve maternal as
well as fetal life.
• Treatment is easy only things required is
early diagnosis and proper management.
