Maternal thyroid physiology is modulated during pregnancy by increases in hCG, urinary iodide excretion, and thyroxine-binding globulin. Thyroid disorders complicating pregnancy include hyperthyroidism, hypothyroidism, and postpartum thyroiditis. Hyperthyroidism is treated during pregnancy with antithyroid medications to maintain normal thyroid hormone levels. Hypothyroidism requires increasing levothyroxine doses during pregnancy. Postpartum thyroiditis involves transient hyperthyroid and hypothyroid phases due to thyroid autoimmunity after delivery.

1. THYROID COMPLICATING
PREGNANCY

2. THYROID GLAND

3. MATERNAL THYROID PHYSIOLOGY
During pregnancy, maternal thyroid function is
modulated by three factors
• An increase in HCG concentrations that stimulate
the thyroid glands,
• Significant increases in urinary iodide excretion,
resulting in a fall in plasma iodine concentrations,
• An increase in thyroxine-binding globulin (TBG)
during the first trimester, resulting in increased
binding of thyroxine

4. THYROID IN PREGNANCY
• Thyroid hormone concentrations in blood are
increased in pregnancy, partly due to the high
levels of oestrogen and due to the weak
thyroid stimulating effects of human chorionic
gonadotropin(hCG) that acts like TSH.
• Thyroxine (T4) levels rise from about 6–12
weeks, and peak by mid-gestation; reverse
changes are seen with TSH

6. AUTOIMMUNE THYROID DISEASE
 There are mainly two types of thyroid antibodies: Those that are
directed towards cytoplasmic antigen(thyroid peroxidise(TPOAb) and
thyroglobulin (TgAb) antibodies) and those directed to the TSH
receptor(TSHRAb).
 The thyroid autoimmunity,with normal thyroid function ,has been
associated with increased miscarriage rate which may be due to:
 Subtle maternal thyroid dysfunction
 An underlying autoimmune imbalance reflected by the presence of
thyroid antibodies which result in rejection of the fetus.
 Thyroid antibodies which crosses the placenta and directly affecting
the developing fetal thyroid gland ,increase early loss
 Increased maternal age of women with thyroid autoimmunity

7.  Definition: It is defined by excessive thyroid
hormone production due to an overactive gland.
 Incidence: Hyperthyroidism occurs in about 2
per 1000 pregnancies
 Types: Based on biochemical test
 Subclinical:- suppressed TSH ,normal T4 and T3
 Overt:- suppressed TSH and elevated T4 and /or
T3

8. Causes :
• Intrinsic thyroid disease :
• Autoimmune
hyperthyroidism(Grave’s
disease) due to thyroid
stimulating antibody
• Nodular thyroid disease –
single or multiple –nodule >3
cm
• Sub – acute thyroiditis –
generalised thyroid tenderness
• Excessive ,exogenous thyroid
hormone
• Factitious
• Therapeutic
• Gestational thyrotoxicosis:
• Hyperemesis gravidarum
• Placenta mediated
• Hydatidiform mole
• Multiple gestation
• hydrops
• Trophoblastic diseases

9.  Restlessness
 Fatigue
 Weakness
 Weight loss
 Diarrhoea
 Heat intolerance
 Nervousness
 Tachycardia/palpitations
 Increased frequency of bowel habits
 Skin/hair/nail changes
 Skin is soft and moist

10.  Onycholysis (separation of distal nail from its
bed)
 Hair becomes soft,fine and may thin
 Eye signs
 Lid lag
 Lid retraction and stare

11. Specific to grave’s disease:
 Grave’s orbitopathy
 Chemosis
 Proptosis
 Dysconjugate gaze
 Pretibial myxedema
 Thyroid bruit
 Clubbing

12. On examination, patient may exhibit
 Tachycardia
 Tremor
 Goitre
 Muscle weakness
 Lid retraction or lag
 TSH decreased and T4 elevates
 Patients with grave’s disease may have antibodies
to thyroid peroxidise or TSH receptor.

13.  Clinical diagnosis of hyperthyroidism is
always be confirmed by measuring free T4
and T4 levels along with TSH
 Suggestive complaints include nervousness,
heat intolerance, palpitations, thyromegaly or
goitre, failure to gain weight or loss weight,
exophthalmos.
 Women with gestational thyrotoxicosis are
rarely symptomatic,have minimal thyroid
enlargement and are TSHRAb negative

14.  Antithyroglobulin antimicrosomal antibodies
and thyroid stimulating immunoglobulin
should be measured
 Radioactive iodine uptake and scans should
not be done during pregnancy as it cross the
placenta and damage the fetal thyroid gland
permanently

15.  The goal of management of thyrotoxicosis is
primarily to normalize ,but not to suppress
thyroid hormone levels and to secondarily
treat bothersome adrenergic symptoms of
hyperthyroidism
 Treatment of hyperthyroidism in pregnancy
focuses on stopping release of T4 and
inhibiting conversion of T4 to T3

16.  Treatment options for nonpregnant women
include treatment for 12 – 24 months with
antithyroid drugs, radioactive iodine to
partially ablate the thyroid gland and near
total thyroidectomy.
 Use of antithyroid drugs (carbimazole,
methimazole, propylthiouracil)

17.  Thyroid function should be assessed every 4-
6 weeks.
 Subtotal thyroidectomy is an option for
patients who are noncompliant or refractory
to medications.Surgery is best undertaken in
the second trimester.Radioiodine treatment is
contraindicated in pregnancy.
 Thyrotoxicosis or thyroid storm is treated
with large dose of PTU,600mg loading dose
,followed by 200 – 300mg every 6 hrs should
be administered

18.  Pregnancy outcomes
 Thio – amide drugs
 Radio – ablative therapy

19. ANTENATAL MANAGEMENT:
 The goal of the treatment during pregnancy is to maintain free T4
in the upper normal range with lowest dose of thio amides.
 Treatment with beta blockers for the symptomatic relief of severe
adrenergic symptoms until freeT4 levels are normalised
 Women on thio –amide prior to pregnancy or newly diagnosed
toxic nodules or Grave’s disease should be continued or started
on thio amide during pregnancy.
 The usual starting dose of PTU is 50 – 100 mg 3 times a day and
methiomezole 5 – 20 mg twice daily.
 Thyroid studies should be repeated every 4 weeks and the
dosage should be based on T4 level and not on TSH level .
Dosage should be reduced when the T4 level reaches the normal.

20. FETAL MONITORING:
 Foetuses of women taking antithyroid drug during the
third trimester or those with a persistent TSHRAb
have an increased risk for developing goiter.
 Because of the placental transfer of thyroid
stimulating immunoglobulins fetal grave’s disease
may develop that results in nonimmune hydrops or
fetal demise.
 Documentation of fetal heart rate at each visit and
USG every 2- 4 weeks in the third trimester
 If any fetal abnormlity present routine fetal blood
sampling for thyroid indices are recommended

21. Labor and delivery:
 Treatment of symptomatic women with
hyperthyroidism in labor include antithyroid
medication , beta – blockers if necessary and
supportive care.
 If thyrotoxicosis is suspected in labor
appropriate management include –elective
caesarean delivery may be suitable to avoid
dystocia from an extremely large fetal goitre
and for the management of fetal airway.
 The ex utero intrapartum treatment(EXIT)
was developed to to manage airway
obstruction with large neck masses.

22.  There may be relapse of Grave’s disease
usually within the first 3 months after
delivery
 Antithyroid therapy needs to be
reintroduced.
 Perform TSH and free T4 approximately 6
weeks post partum.
 Methimazole cause thyroid dysfunction in
breast feeding infants .In low dose (10 – 20
mg/day) does not pose a major risk to
nursing infants.

23.  Miscarriage
 Pre-term delivery
 Pre-eclampsia
 CCF
 Placental abruption
 Thyroid storm
 Infection

24.  IUGR
 Prematurity
 Stillbirth
 Hyperthyroidism
 Hypothyroidism
 Increased perinatal mortality and morbidity

25. HYPOTHYROIDISM
• Definition: It is defined as inadequate thyroid
production despite pituitary gland
stimulation(primary) or insufficient stimulation
of the thyroid by the pituitary or hypothalamus.
(central hypothyroidism)
• Incidence: 1-3 per 1000 pregnancy
• Types:
• Subclinical:- elevated TSH and normal free T4
• Overt:- elevated TSH and low free T4

26. HYPOTHYROIDISM
Causes:
• Autoimmune distruction of thyroid
gland(hashimoto’s thyroiditis) –most common
• Iodine deficiency – leading cause
• Radio ablation of the thyroid for Grave’s disease
or thyroid nodule
• Thyroidectomy – partial or near complete for
treatment of benign or malignant
neoplasm,Grave’disease)
• Medications – Lithium,amioderone

27. HYPOTHYROIDISM
Signs and symptoms:
• vague ,nonspecific signs and symptoms that are
insidious in onset
• fatigue
• constipation
• cold intolerance
• weight gain
• carpel tunnel syndrome
• hair loss
• voice changes
• reduced memory
• muscle cramps
• dry skin

28.  Diagnosis during pregnancy is very
difficult
 serum TSH is more sensitive than free T4 for
detecting hypothyroidism.If TSH is
abnormal , then elevation of free T4 is
recommended.
 The range for serum TSH concentration in
nonpregnant individual is 0.45 – 4.5 mU/L

29.  Strong family history
 Known autoimmune disease
 Presence of goitre
 Previous therapeutic neck irradiation
 Those taking medication known to cause
thyroid disturbance
 TSH testing for hypothyroidism should
ideally be done prior to pregnancy

30. Management:
Discussion of
 the importance of euthyroidism at the time of
conception
 Risk of hypothyroidism to mother and off
spring
 Anticipation of medication changes during
pregnancy

31. Management:
Preconceptional councelling:
 The goal of treatment is bringing a euthyroid state
at the time of conception
 TSH should be considered as an indication of
adequate replacement and women should delay
pregnancy until TSH is normal
 Do not take levothyroxine and multivitamins at the
same time since iron and calcium may interfere
with absorption of thyroxine
 All women should have adequate iodine intake
(200microgram/day)

32. Antenatal management:
 By 16 week of gestation women need an
increase in thyroid hormone by 47 %.
 This begins as early as 5th week of gestation
and those with previous history of
thyroidectomy
 Patients can be told to take a double dose of
their levothyroxine on two days out of seven
 A low normal TSH is the goal during
pregnancy (<2.5mU/ml)

33. Antenatal management:
 Newly diagnosed women during pregnancy
should be initiated on 1.0 – 2.0 microgram/kg
/day or 100 microgram of levothyroxine daily
 Thyroid stimulating hormone should be
measured in 6 weeks and levothyroxine dose
adjusted in 25 or 50 microgram
 When normalized TSh should be checked
every 6 -8 weeks through out pregnancy

34. Labor and delivery:
 Known hypothyroid women should be
euthyroid before delivery
 Obstetric complications include increased risk
of still birth , pre term delivery , pre –
eclampsia,and placental abruption,increased
risk of breech and low birth weight

35. Post partum care:
 After delivery levothyroxine therapy should be
returned to the prepregnant dose and the TSH
should be checked in 6 – 8 weeks
 Breastfeeding is not contraindicated in women
treated for hypothyroidism. Levothyroxine is
excreated into breast milk but levels are too
low to alter thyroid function in infants
 Annual monitoring of serum TSH is
recommended as changing weight and age
may modify thyroid function.

36. POST PARTUM THYROIDITIS
 Post partum thyroiditis is caused by a rebound in
thyroid autoimmunity after delivery leading to
lymphatic infiltration of the thyroid gland and
transient changes in the thyroid function.

37. POST PARTUM THYROIDITIS-
Clinical phases:
 Phase 1:- The autoimmune destruction of the gland
first results in release of stored thyroid hormone into
the circulation. This hyperthyroid phase generally
occurs between 1 and 4 months after delivery and is
self limiting to 1 – 2 months. The onset is abrupt ,with
symptoms of fatigue and palpitation . A small painless
goitre may develop. If these symptoms become severe ,
it require treatment with Beta – blockers until
resolution of hyperthyroid phase. Antithyroid
medications are not beneficial.

38. POST PARTUM THYROIDITIS-
Clinical phases:
 Phase 2:
The loss of functioning thyrocytes from the immune destruction
results in hypothyroid phase between 3 and 8 months
postpartum. The hypothyroid phase usually last longer than
hyperthyroid phase ( 4 – 6 months). This disorder is often
unrecognised because women usually present with nonspecific
symptoms including fatigue , weight gain , loss of concentration
and depression. The hypothyroid phase should be treated in
women who are symptomatic and in those planning a pregnancy
near in future. It is usually recommended to treat women for
approximately for 6 months and withdraw thyroid hormone ,
unless pregnancy is being attempted. A TSH should be
rechecked in 5 – 6 weeks after withdrawal of thyroid hormone.

39. Nursing care:
 Education of the pregnant women is necessary
to plan treatment.
 Discuss with the women and her family members
about the outcome.
 Assist the client to cope with the discomfort and
frustrations due to symptoms.
 Nutritional councelling with a registered dietician
will help in selecting a well balanced diet.