II. Definitions
- Postpartum Thyroiditis
- Painless Thyroiditis (with abnormal TSH) in the first 12 months following pregnancy (including Miscarriage)
- Does not include patients with toxic Thyroid Nodule or Grave's Disease with Thyrotropin receptor Antibody positive
III. Epidemiology
- Occurs in 1 to up to 10% of postpartum patients
IV. Pathophysiology
- Painless, autoimmune Thyroiditis
- Similar pathophysiology to Hashimoto's Thyroiditis
- Associated with HLA-DRB, HLA-DR4 and HLA-DR5
- Pregnancy is an Immunocompromised (or immuno-tolerant) state
- Postpartum Thyroiditis is concurrent with a rebound in immune function
V. Risk Factors
-
Antithyroid Peroxidase Antibody (TPO Antibody) positive (25% risk)
- Associated with Thyroiditis risk, even if euthyroid
- Predicts recurrent Thyroiditis in future pregnancies
- Other autoimmune disorders (e.g. Type I Diabetes Mellitus)
- Postpartum Depression
- Family History of autoimmune Thyroiditis
VI. Types: Postpartum Thyroiditis
-
Hypothyroidism (40%)
- Occurs within 12 months (typically 4-8 months) of delivery (mean: 6 months)
- Duration 4-6 months (although permanent Hypothyroidism occurs in 25% of women)
-
Hyperthyroidism (30%)
- Occurs within 10 months (most within 6 months) of delivery (mean: 3 months)
- Resolves spontaneously within 2-3 months of onset
- Asymptomatic in one third of patients
- Milder than Graves Disease in those that are symptomatic
- Unlike Graves Disease, no Exophthalmos or Thyroid bruit and TSH Receptor Antibody negative
- Lower Free T3 to Free T4 ratio than with Graves Disease
- Triphasic: Initial Hyperthyroidism, then Hypothyroidism, then euthyroid (25% to 40%)
- Hyperthyroidism phase: Onset 2 to 6 months postpartum, and lasts 2 to 3 months
- Hypothyroidism phase: Onset 3 to 12 months postpartum
VII. Complications: Persistent Hypothyroidism (30-50%)
- Hypothyroidism persists or recurs within 9 years
- Risk factors for longterm hypothyrodism
- Initial Hypothyroidism at onset of thyoriditis
- Antithyroid Microsomal Antibody at high titer
- Thyroid Ultrasound with hypoechogenic pattern
VIII. Differential Diagnosis
- See Painless Thyroiditis
- Hashimoto's Thyroiditis (hypothyroid phase)
- Toxic Thyroid Nodule (thyrotoxic phase)
-
Grave's Disease (thyrotoxic phase)
- Very important to differentiate (also presents in Postpartum Period)
- Thyrotropin receptor Antibody positive
- Contrast with TPO Antibody and Thyroglobulin Antibody present in Postpartum Thyroiditis
- Radioactive Iodine Uptake Scan with increased uptake
IX. Labs
- Thyroid Function Testing (results depend on Thyroiditis phase)
-
Antithyroid Peroxidase Antibody (TPO Antibody) positive (80%)
- Similar to Hashimoto's Thyroiditis
-
Erythrocyte Sedimentation Rate (ESR) normal
- Contrast with Hashimoto's Thyroiditis
-
Thyroid stimulating receptor Antibody negative
- Contrast with Grave's Disease
X. Imaging
-
Radioiodine Uptake (RAIU Scan)
- Suppressed uptake in hyperthyroid phase (Contrast with Grave's Disease in which uptake is increased)
- Do not perform if Breast Feeding
- Avoid close contact with infant following scan for period designated by imaging department
- Thyroid Ultrasound with doppler
- No increased Blood Flow (Contrast with Grave's)
XI. Management
- Postpartum Hyperthyroidism
- Beta Blockers if symptomatic (caution in Lactation)
- Propranolol 10-20 mg orally four times daily as needed
- No effect with antithyroid medications (Propylthiouracil or Methimazole)
- Follow TSH and T4 Free
- Anticipate resolution within 2-3 months
- May be followed by Hypothyroidism (see types above)
- Beta Blockers if symptomatic (caution in Lactation)
- Postpartum Hypothyroidism
- Levothyroxine for symptomatic Hypothyroidism, Breast Feeding or planning conception
- Start at 50 mcg orally daily
- Taper the dose after 12 months of therapy
- Reduce dose by 50% each cycle, followed by a recheck TSH at 4-8 weeks after each dose change
- Expect 75% of patients will be euthyroid off medication
- Follow Serum TSH
- Goal Serum TSH 1.0 to 2.5 mIU/L
- Anticipate Thyroid normalizing by 6-9 months (up to 18 months) in 80% of cases
- Lifelong Thyroid Replacement therapy with Levothyroxine may be required (up to 20-25% of cases)
- Levothyroxine for symptomatic Hypothyroidism, Breast Feeding or planning conception
XII. Prevention
- Screen pregnant women with risk factors (see above)
XIII. Prognosis
- Recurrence with subsequent pregnancies is common (up to 70% of cases)
- Risk of lifelong Hypothyroidism (15 to 50% of cases)
- Annual Serum TSH screening in all patients with history of Postpartum Thyroiditis
XIV. References
- Bindra (2006) Am Fam Physician 73(10):1769-76 [PubMed]
- Carney (2014) Am Fam Physician 89(4): 273-8 [PubMed]
- De Groot (2012) J Clin Endocrinol Metab 97(8): 2543-65 [PubMed]
- Quintero (2021) Am Fam Physician 104(6): 609-17 [PubMed]
- Stagnaro-Green (2011) Thyroid 21(10): 1081-125 [PubMed]
- Stagnaro-Green (2002) J Clin Endocrinol Metab 87:4042-7 [PubMed]
- Sweeney (2014) Am Fam Physician 90(6): 389-96 [PubMed]
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Definition (NCI) | Inflammatory disorder of thyroid gland that occurs postpartum due to any partum problem. |
Definition (MSH) | Transient autoimmune thyroiditis occurring in the POSTPARTUM PERIOD. It is characterized by the presence of high titers of AUTOANTIBODIES against THYROID PEROXIDASE and THYROGLOBULIN. Clinical signs include the triphasic thyroid hormone pattern: beginning with THYROTOXICOSIS, followed with HYPOTHYROIDISM, then return to euthyroid state by 1 year postpartum. |
Concepts | Disease or Syndrome (T047) |
MSH | D050032 |
ICD10 | O90.5 |
SnomedCT | 199241008, 52772002 |
Swedish | Postpartumtyreoidit |
Czech | thyreoiditis poporodní, tyreoiditida poporodní |
Finnish | Synnytyksenjälkeinen kilpirauhastulehdus |
Russian | TIREOIDIT POSLERODOVOI, ТИРЕОИДИТ ПОСЛЕРОДОВОЙ |
English | postpartum thyroiditis (diagnosis), postpartum thyroiditis, Postpartum Thyroiditis [Disease/Finding], thyroiditis postpartum, Postpartum thyroiditis, Postpartum thyroiditis (disorder), postpartum; thyroiditis, thyroiditis; postpartum, Post partum Thyroiditis, Post-partum Thyroiditides, Post-partum Thyroiditis, Postpartum Thyroiditides, Postpartum Thyroiditis, Thyroiditides, Post-partum, Thyroiditides, Postpartum, Thyroiditis, Post-partum, Thyroiditis, Postpartum |
Japanese | 出産後自己免疫性甲状腺症候群, 甲状腺炎-出産後, 分娩後一過性甲状腺中毒症, 甲状腺炎-分娩後, 分娩後甲状腺炎, 出産後甲状腺炎 |
Korean | 분만후 갑상샘염 |
French | Thyroïdite du post-partum, Thyroïdite du postpartum |
Portuguese | Tireoidite Pós-Parto |
Polish | Zapalenie tarczycy poporodowe |
Norwegian | Postpartum tyreoiditt, Tyreoiditt etter fødsel |
Dutch | post partum; thyroïditis, thyroïditis; post partum, Thyroïditis post partum |
Spanish | tiroiditis posparto, tiroiditis postparto (trastorno), tiroiditis postparto, Tiroiditis Posparto |
German | Postpartale Thyreoiditis, Thyreoiditis, postpartale |
Italian | Tiroidite postpartum |