medical disorders in pregnancy- emergency obstetrics

1. Thyroid Storm
During Pregnancy
Dr Yashodhara
gaur

2. Introduction
● Thyroid storm is an Endocrinology emergency which characterized by acute
hypermetabolic with rapid deterioration which is one of non-obstetric maternal
death cause
● Thyroid storm is a rare serious complication in hyperthyroidism patients (1-2% of
cases of hyperthyroidism)
● Incidence of hyperthyroidism in pregnancy is about 0.2% and mostly subclinical
● 90-95% of pregnant women with hyperthyroidism are manifestations of Grave’s
disease
● Adult mortality rate in the thyroid storm is 10-20% due to the late diagnostic and
treatment Biomedical & Pharmacology Journal, September 2018.

3. Changes in Thyroid Function Test Results in Normal
Pregnancy and in Thyroid Disease
The level of TSH decreases in early pregnancy because of weak TSH receptor stimulation
due to substantial quantities of human chorionic gonadotropin during the first 12 weeks of
gestation. After the first trimester, TSH levels return to baseline values
Maternal status TSH Free T4
Pregnancy Varies by trimester No change
Overt hyperthyroidism Decrease Increase
Subclinical
hyperthyroididsm
Decrease No change
Overt hypothyroidism Increase Decrease
Subclinical
hypothyroidism
Increase No change

4. Signs and symptoms of thyroid storm
● Hyperthermia
● Nausea
● Abdominal pain
● Vomiting
● Severe agitation
● Diaphoresis
● Dehydration
● Tachycardia
● Congestive heart failure
● Arrhythmia
● Confusion
● Cardiovascular collapse
● Malignant exophthalmos

5. Diagnostic criteria for Thyroid Storm
1. Burch-Wartofsky Point Scale
2. Japanese Thyroid Association (JTA) diagnostic criteria

6. Burch-Wartofsky Point Scale
Burch-Wartofsky Point Scale (BWPS) for diagnosis of TS, proposed in 1993, is
an empirically derived scoring system, which considers the precipitating factors
and the severities of symptoms of multiple organ decompensation
● Thermoregulatory dysfunction
● Tachycardia/ atrial fibrillation
● Disturbances of consciousness
● Congestive heart failure
● Gastro-hepatic dysfunction

7. Total score
> 45 Thyroid storm
25-44 Impending storm
< 25 Storm unlikely
Burch-Wartofsky Point Scale

8. JTA New Diagnostic Criteria
● In 2012, the Japanese Thyroid Association (JTA) proposed new diagnostic
criteria for thyroid storm that were initially established based on detailed
analyses of 99 published cases and 7 taskforce committee’s cases and finally
revised according to the results of nationwide surveys
● In these JTA criteria, the presence of thyrotoxicosis is required as a prerequisite
condition, and definite and possible thyroid storm can be diagnosed based on
specific combinations of symptoms due to multiple organ decompensation,
similarly to those listed in the BWPS
● One of the specific features in the JTA criteria is that disturbances of
consciousness contribute to the diagnosis of thyroid storm much more than
other organ symptoms
Thyroid 2012; 22: 661-679.

9. JTA New Diagnostic Criteria

10. JTA New Diagnostic Criteria
Exclusion & Provisions (Differential Diagnosis)
Cases are excluded if other underlying diseases clearly causing any of the
following symptom
● Fever (e.g., pneumonia and malignant hyperthermia)
● Impaired consciousness (e.g., psychiatric disorders and cerebrovascular
disease)
● Heart failure (e.g., acute myocardial infarction)
● Liver disorders (e.g., viral hepatitis and acute liver failure).
It is difficult to determine whether the symptom is caused by TS or is simply a
manifestation of an undelying disease; the symptom should be regarded as
being due to a TS that is caused by these precipitating factors. Clinical judgment
in this matter is required.
cont…

11. JTA New Diagnostic Criteria
TS1: “Definite” TS
TS2: “Suspected” TS

12. BWPS vs JTA
● Usefulness of the BWPS and JTA criteria has been compared by analyses of
JTA nationwide surveys, and two institutions showed overall agreement
between the two systems
● A report from the United States suggested that the BWPS ≥ 45 appeared to
select a higher percentage of patients for aggressive therapy than the JTA
criteria
● Using both diagnostic systems to evaluate a patient’s condition is
recommended to increase the accuracy of clinical diagnosis and further
validate the usefulness of these two sets of criteria
Endocr Pract 2015; 21: 182-189
J Clin Endocrinol Metab 2015; 100: 451-459

13. BWPS vs JTA
● Inappropriate application of either system can lead to misdiagnosis of thyroid
storm, emphasizing the importance of carefully evaluating the clinical
condition of each patient suspected of having thyroid storm
● In cases where physicians are having difficulty judging whether the symptoms
listed in the JTA criteria have arisen from precipitating events or from thyroid
storm, the symptoms should be judged as having been caused by thyroid
storm, as described in the JTA criteria.
Endocr Pract 2015; 21: 182-189
J Clin Endocrinol Metab 2015; 100: 451-459

14. D/d of CNS manifestations in thyroid storm patients
Endocrine Journal 2016; 63(12): 1025-1064

15. Diagnostic algorithm

16. Principle of Thyroid Storm Management
I. Reduce the synthesis and secretion of thyroid hormones
II. Decrease the peripheral effects of thyroid hormone
III. Inhibit the conversion of T4 to T3
IV. Therapy to prevent systemic decompensation
V. Trigger disease therapy
VI. Pregnancy management and supportive therapy
Endocrine Journal.; 63(12):1025-64 (2016).

17. Treatment of Thyroid Storm
A. Inhibit thyroid release of T3 and T4
● Propylthiouracil, 1,000 mg PO load, then 200 mg PO every 6 hours
● Iodine administration 1–2 hours after propylthiouracil by
○ Sodium iodide, 500–1,000 mg IV every 8 hours
○ Potassium iodide, five drops PO every 8 hours
○ Lugol solution, 10 drops PO every 8 hours
○ Lithium carbonate (if patient has an iodine anaphylaxis history), 300 mg
PO every 6 hours

18. Treatment of Thyroid Storm
B. Further block peripheral conversion of T4 to T3
● Dexamethasone, 2 mg IV every 6 hours for four doses
or
● Hydrocortisone, 100 mg IV every 8 hours for three doses

19. Treatment of Thyroid Storm
C. β-Blockers to decrease effects on the cardiovascular system
● Propranolol, labetalol, and esmolol all have been used successfully
● If a β-blocking drug is given to control tachycardia, its effect on heart failure
also must be considered

20. Treatment of Thyroid Storm
Supportive measures
● Administration of intravenous fluids for dehydration
● Antipyretics for control of hyperthermia (a cooling blanket may be necessary)
● Nutritional support
● Correction of possible electrolyte imbalances
● If sedation is required, barbiturates are most often used because they lower
the levels of thyroid hormones by increasing the catabolism of the hormones.
● Oxygen should be used as needed for possible increased oxygen demands
● Close assessment and monitoring of cardiovascular status, including
continuous cardiac monitoring and frequent monitoring of vital signs
● Significant changes should be reported immediately

21. Prevention of thyroid storm
● The gold standard of treatment of thyroid storm is primary prevention
● Prevention of thyroid storm requires careful control and management of the
hyperthyroidism
● Standard treatment options for Graves disease
Radioactive
iodine
Surgery
Antithyroid
agents
Destruction of thyroid gland
in the fetus
Risk for miscarriage or
preterm delivery
Standard treatment
during pregnancy

22. Prevention of thyroid storm
Antithyroid agents
● ATDs inhibit the biosynthesis of thyroid hormones
● Because of the immunosuppressive effect of pregnancy, ATDs can be given
in lower doses in pregnant patients than in nonpregnant patients
● Every attempt should be made to treat with the lowest possible effective dose
of ATDs because these drugs can cross the placenta, enter the fetal
circulation, and affect the thyroid gland of the fetus.

23. Prevention of thyroid storm
Propylthiouracil
● Drug of choice during pregnancy
● ADR (5%): Fever, rash, urticaria,
arthralgias, leukopenia
● Rare event: Agranulocytosis
(fever, sore throat)
● Dose: 300-450 mg per day
divided into three doses
Methimazole
● Associated with aplasia cutis (a
localized lesion in the parietal area
of the scalp, characterized by
congenital absence of the skin,
punched-out “ulcer” lesions, that
usually heal spontaneously) in the
offspring

24. Thyroid Storm & Delivery
● Current recommendations are
to avoid delivery during thyroid
storm unless the condition of
the fetus demands prompt
delivery.

25. Fetal and Neonatal Thyrotoxicosis
● Transplacental passage of Thyroid-stimulating immunoglobulins can result in
fetal and neonatal thyrotoxicosis, although this complication is rare.
● It occurs in only 1% of babies born to women with a history of Graves
disease, but it may have serious consequences if not recognized.
Complications
● Hyperthyroidism
● Tachycardia
● Intrauterine growth retardation
● Size small for gestational age
● Prematurity
● Stillbirth
● Advanced bone age
● Craniosynostosis
● Feedback suppression of the fetal
● Hypothalamic-pituitary-thyroid axis