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Medical Disorders in Pregnancy

Thyroid Disease in Pregnancy

IN REVIEWv3🌍 International referencePENDING CLINICAL VERIFICATION
Treat overt hypothyroidism with TFT-guided levothyroxine. Graves treatment uses the lowest effective antithyroid dose, with PTU favoured early and a possible carbimazole switch beyond 20 weeks. Thyroid storm requires ICU-led treatment with attention to cardiac function, liver risk and iodine timing.

Admission & discharge ↓

Reviewer note: Medication regimens and dependent emergency instructions checked 17 October 2026. These targeted checks do not certify every statement in the module. Admission/discharge guidance checked 18 October 2026. This adds a scoped clinical synthesis and does not certify every statement in the module.

Admission & discharge

Care setting: Usually outpatient; thyroid storm or severe decompensation requires admission

Admission/discharge guidance checked 2026-10-18 against the linked sources. This is a clinical checklist for an individual decision, not an automatic discharge order.

When admission or continued hospital care is needed

  • Admit suspected thyroid storm, significant arrhythmia/heart failure, severe systemic illness or inability to take essential treatment.

When clinic, day care or home care may be suitable

  • Stable treated hypo-/hyperthyroidism can be followed with scheduled TFTs and specialist obstetric/endocrine care.

Before going home

  • The acute cardiac/systemic problem is controlled, oral treatment is established and liver/thyroid monitoring and specialist follow-up are organised.
  • If Graves disease/antithyroid treatment affects neonatal risk, the birth/neonatal team has the relevant history and antibody/treatment information.

Discharge medicines and treatment changes

  • Continue the agreed replacement/antithyroid medicine; do not stop it solely because delivery has occurred. Record any postpartum dose change and TFT date.
  • Explain urgent action for possible antithyroid drug toxicity, including fever/sore throat or jaundice, and avoid routine block-and-replace treatment.

Tests, pending results and their reviewer

  • Assign TFT follow-up after a dose change and the postpartum review; assess additional tests according to the illness/drug used.

Home care and counselling

  • Give written medicine instructions, toxicity warnings and a neonatal plan when relevant.

Follow-up: when and what to review

WhenAction / responsible service
At the scheduled TFT/specialist review
Adjust treatment from the measured results, not symptoms alone.
After birth
Follow the individual replacement/Graves plan and ensure neonatal assessment when indicated.

Return urgently

  • Fever with marked tachycardia/confusion, breathlessness/chest pain, collapse, jaundice or possible drug-related agranulocytosis requires urgent assessment.

Open the complete discharge checklist →

Sources for this plan:
RCOG · 2025; May 2026 correction checkedcheckedSociety for Endocrinology / BTA / ETA joint consensus, Taylor et al.checked

Treatment

① Immediate stabilization — first minutes

Storm: stabilise BEFORE any delivery decision unless obstetric indication forces it.

③ First-line treatment & drug regimens
Levothyroxine — established hypothyroidismRCOG · 2025; May 2026 correction checkedchecked
DoseAt positive pregnancy test increase the weekly dose by about 25–30%, e.g. double the usual daily dose on two days each week; then titrate to TFTs
RouteOral
FrequencyDaily, with a clearly written seven-day dose schedule
DurationThrough pregnancy; make an individual postpartum dose plan and repeat TFTs about 6 weeks after birth
PreparationUse the prescribed microgram-strength tablets consistently before breakfast; separate oral iron/calcium by 4–5 hours. Micrograms are not milligrams
Max doseNo universal fixed maximum: titrate to pregnancy-specific TFTs; the initial 25–30% rise is not an instruction for repeated weekly increases
  • Already receiving replacement before pregnancy
  • Pre-existing adequately treated disease generally returns to the preconception dose after birth according to the RCOG postpartum plan; reassess rather than automatically stopping permanent replacement.
Monitoring
  • TSH/FT4 every 4–6 weeks to 20 weeks and again at 28 weeks; target TSH <2.5 mIU/L with FT4 in the pregnancy reference range
Contraindications: Untreated adrenal insufficiency requires assessment/treatment; avoid overreplacement in cardiac disease
Levothyroxine — newly diagnosed in pregnancyRCOG · 2025; May 2026 correction checkedchecked
DoseOvert/severe disease: 1.6 micrograms/kg/day initial replacement. For selected subclinical disease with TSH above the gestational range but ≤10, consider 1.0–1.2 micrograms/kg/day after discussing benefit
RouteOral
FrequencyOnce daily
DurationRecheck TFTs after 4 weeks and titrate; postpartum continuation/withdrawal depends on the original diagnosis, dose and TFTs
PreparationCalculate weight-based MICROGRAMS, prescribe an achievable tablet-strength schedule, take before breakfast and separate iron/calcium by 4–5 hours
Max doseIndividualised TFT-guided dosing, not a fixed universal maximum
  • RCOG: overt hypothyroidism or TSH >10 mIU/L; distinguish milder subclinical disease
  • The milder subclinical-treatment decision is separate from the clear indication to treat overt hypothyroidism.
Monitoring
  • TSH/FT4 after initiation and every 4–6 weeks during titration; reassess adherence and absorption before increasing
Contraindications: Do not treat isolated low FT4 with normal TSH routinely; untreated adrenal insufficiency or cardiac disease requires specialist review
Propylthiouracil — Graves titrationWockhardt / emcchecked
DoseProduct adult initial range 300–600 mg/day in divided doses until controlled; then usually 50–150 mg/day. In pregnancy use the lowest effective dose, individually selected from FT4 and severity, rather than automatically starting at the upper adult range
RouteOral
FrequencyDivide the prescribed daily dose, commonly every 8 hours
DurationTitrate with specialist follow-up; if still needed beyond 20 weeks consider changing to carbimazole because of PTU hepatotoxicity
Preparation50 mg tablets; prescribe the exact mg per administration. Do not confuse the outpatient dose with the separate thyroid-storm loading regimen
Max dose600 mg/day is the top of the cited adult starting range, not a routine pregnancy target or an instruction to escalate without endocrine review
  • Overt hyperthyroidism requiring antithyroid medication; preferred early-pregnancy option when appropriate
  • RCOG: use the lowest dose maintaining FT4 in the upper half of its pregnancy range; do not titrate to a suppressed TSH alone. Do not use routine block-and-replace.
  • Renal / hepatic: SmPC: GFR 10–50 mL/min use 75% dose; GFR <10 use 50%; reduce in hepatic disease with specialist review.
Monitoring
  • FT4/TSH every 2–4 weeks initially; urgent CBC for fever/sore throat; liver assessment for jaundice, dark urine or abdominal pain
Contraindications: Previous PTU-associated hepatic injury/agranulocytosis; significant liver disease requires specialist choice
Carbimazole — Graves titrationManufacturer / emcchecked
DoseAdult product initial range 20–60 mg/day in 2–3 divided doses; maintenance usually 5–15 mg/day. Pregnancy requires the lowest effective dose. When switching, PTU 200 mg/day is approximately carbimazole 10 mg/day (20:1)
RouteOral
FrequencyInitially divided 2–3 times daily; maintenance may be once daily
DurationReassess TFTs within 2 weeks after a switch/dose change; continuation through pregnancy and after birth is individualised
PreparationUse the stated tablet strength to deliver the exact mg; carbimazole and methimazole are not mg-for-mg equivalent
Max dose60 mg/day is the adult label starting-range ceiling, not a routine pregnancy goal; thyroid-storm treatment is a separate regimen
  • Specialist antithyroid option; pregnancy timing and PTU suitability determine selection
  • RCOG advises considering PTU→carbimazole if antithyroid treatment is still needed beyond 20 weeks, rather than an automatic switch at the end of trimester 1. Routine block-and-replace is not recommended.
Monitoring
  • FT4/TSH, fever/sore-throat agranulocytosis warning, liver symptoms; fetal/neonatal surveillance when indicated
Contraindications: Previous carbimazole/thiamazole-associated pancreatitis, serious marrow or liver disorder; first-trimester embryopathy risk requires specialist counselling

Routine antithyroid block-and-replace is not recommended in pregnancy because of fetal hypothyroidism/goitre risk. Rare isolated fetal hyperthyroidism is an expert exception. Radioiodine is contraindicated during pregnancy.

Definitive treatment

Thyroidectomy rarely (compressive/refractory) - best second trimester.

Monitoring
  • Replacement: TFTs every 4–6 weeks to 20 weeks and again at 28 weeks; recheck after dose changes.
  • Antithyroid treatment: FT4/TSH every 2–4 weeks initially; repeat about 2 weeks after a switch. After 20 weeks, follow the specialist 4–8-week schedule when stable.
  • Graves: TRAb in the first trimester; positive results/continued treatment need repeat assessment and fetal surveillance. The corrected RCOG advice starts monthly fetal biometry/Doppler at 26–28 weeks onwards when indicated, not only during that two-week window.
  • Postpartum: document a replacement/antithyroid plan, TFT follow-up and neonatal assessment rather than automatically stopping all treatment.
Response assessment
  • Euthyroid maintenance
Treatment failure
  • Adherence check; absorption interference (iron!); endocrine referral
Second-line treatment
  • Specialist referral refractory disease
Rescue treatment
Thyroid storm: activate ICU/endocrine/obstetric care: Clinical fever, tachyarrhythmia, CNS disturbance or organ dysfunction requires immediate multidisciplinary treatment; do not wait for TFT confirmation. Assess ventricular function before beta-blockade, support airway/circulation, cool, monitor glucose/electrolytes and treat the trigger. Avoid aspirin for fever. The four cards below describe components, with beta-blockade and thionamide choice conditional on cardiac/hepatic status.
Propylthiouracil — thyroid stormSociety for Endocrinology / BTA / ETA joint consensus, Taylor et al.checked
Dose500–1000 mg loading, then 250 mg every 4 hours
RouteOral or NG through a protected airway
FrequencyLoad once, then every 4 hours
DurationAcute high-dose treatment only; reduce promptly as the patient stabilises, with an explicit endocrine maintenance plan
Preparation50 mg tablets: loading 10–20 tablets, maintenance 5 tablets per dose; pharmacy-assisted NG preparation if needed. Record administration before starting iodine
Max doseOne initial load; 1500 mg/day maintenance at 250 mg every 4 h. No repeated loading without specialist reassessment
  • ICU/endocrine-led treatment of storm from increased hormone synthesis; assess pregnancy stage and hepatic function
  • 2026 joint statement: no proven mortality advantage over methimazole/carbimazole; drug selection must consider hepatic injury and pregnancy.
Monitoring
  • Continuous cardiac/haemodynamic monitoring, temperature, mental state, glucose, FT4/FT3 and liver function; treat the precipitant
Contraindications: Significant hepatic dysfunction/previous PTU liver injury favours an alternative thionamide with endocrine/hepatology input; destructive thyroiditis needs a different strategy
Propranolol — thyroid stormSociety for Endocrinology / BTA / ETA joint consensus, Taylor et al.checked
DoseThe consensus lists 60–80 mg every 4 hours; assess cardiac function first and consider a lower initial dose because beta-blockade can precipitate collapse
RouteOral or NG with protected airway
FrequencyEvery 4 hours with reassessment before doses
DurationOnly while required for acute thyrotoxicosis; taper/change as control improves
PreparationImmediate-release tablets, with exact mg prescribed; do not substitute sustained-release tablets or give this as an IV dose
Max doseListed oral schedule totals 360–480 mg/day; this is a specialist ICU regimen, not a routine pregnancy symptom-treatment dose
  • Adrenergic control only in haemodynamically stable patients without significant ventricular dysfunction
  • The 2026 statement emphasises individualisation and the possibility of cardiovascular collapse after beta-blockade.
Monitoring
  • Continuous ECG/BP/perfusion assessment, heart failure and bronchospasm; consider echocardiography before beta-blockade
Contraindications: Shock, decompensated cardiac failure, significant bradycardia/heart block or asthma; short-acting titratable alternatives need critical-care supervision
Hydrocortisone — thyroid stormSociety for Endocrinology / BTA / ETA joint consensus, Taylor et al.checked
Dose100 mg IV loading, then 50 mg every 6 hours
RouteSlow IV injection
FrequencyLoad once, then every 6 hours
DurationStop/review when stable if no accompanying adrenal insufficiency; the ongoing plan depends on cause and duration
PreparationFor the cited 100 mg powder vial add up to 2 mL sterile water for injections; if prepared with 2 mL, concentration is approximately 50 mg/mL: 100 mg=2 mL, 50 mg=1 mL. Give slowly over at least 1 minute and verify the actual product
Max dose2026 joint-statement schedule: 100 mg load plus 200 mg/day maintenance, not a blended older 300 mg loading schedule
  • Glucocorticoid component of ICU storm treatment
  • Preparation cross-checked against the Panpharma 100 mg powder product information; solution ampoules have different concentrations.
Monitoring
  • Glucose, electrolytes, BP, infection and clinical recovery; reassess ongoing adrenal-support need
Contraindications: Life-saving short-course use needs risk assessment rather than delaying treatment; review systemic fungal infection or known steroid hypersensitivity
Potassium iodide — SSKI in thyroid stormSociety for Endocrinology / BTA / ETA joint consensus, Taylor et al.checked
DoseSSKI 5 drops every 6 hours, starting at least 1 hour AFTER the antithyroid drug
RouteOral or NG
FrequencyEvery 6 hours
DurationStop once stabilised/hormone levels controlled; prolonged iodine exposure in pregnancy can affect the fetal thyroid
PreparationUse the pharmacy-verified SATURATED potassium iodide solution (SSKI, 1 g/mL), its calibrated dispenser and prescribed drop volume; dilute in milk/juice before oral/NG administration. Lugol solution is a different formulation and has a different drop prescription
Max dose5 calibrated drops per dose in this regimen; never substitute an arbitrary dropper, radioactive-emergency tablets or Lugol drops
  • Short-course endocrine/ICU therapy after thionamide in hormone-synthesis-driven storm
  • Product concentration confirmed against SSKI prescribing information. Do not prolong iodine in pregnancy without specialist review.
Monitoring
  • Clinical recovery, FT4/FT3, hypersensitivity and pregnancy/neonatal thyroid planning
Contraindications: Do not give before the thionamide; destructive/factitious thyrotoxicosis is not an indication for this synthesis-blocking sequence

Iodine must follow the antithyroid drug by at least one hour. Reassess urgently if not stabilising within 24–48 hours; check drug delivery, ongoing triggers and cardiomyopathy, and consider specialist rescue. Reduce antithyroid intensity and stop iodine/steroid support as clinically appropriate after stabilisation.

Escalation
  • ICU storm
  • Neonatal team alert TRAb+ mothers
⑮ Complications & their management
Fetal/neonatal thyrotoxicosis

Fetal HR surveillance; paediatric ready at birth

Postpartum thyroiditis

TSH 6-12 wks postpartum; manage phases

Post-treatment care
  • Postpartum TFT schedule
  • Breastfeeding-compatible dosing (monitor infant clinically)

Diagnosis & assessment

Red flags:
  • THYROID STORM (fever+tachyarrhythmia+CNS signs)
  • Preterm labour with uncontrolled thyrotoxicosis
  • TRAb-positive neonatal thyrotoxicosis anticipation

Definition: Hypothyroidism, Graves/toxic nodular disease, thyroiditis in pregnancy.

Initial assessment

  1. TSH + FT4 (trimester-specific ranges or ULN 4.0 approach)
  2. TRAb in Graves (neonatal planning)
  3. Eye disease documentation

Investigations

TestLooking for
TFTs q4-6 wks
Titration axis
TRAb
Fetal risk stratification

Principles & follow-up

Management principles

Sources (9)

RCOG — Management of Thyroid Disorders in Pregnancy — Green-top 76 (2025)
2023 (BJOG publication year per index listing) · checked 2026-10-17 · verified-live
Open source ↗

Full primary guideline checked for existing/new levothyroxine dosing, TFT follow-up, lowest-effective-dose antithyroid treatment, no routine block-and-replace and considering PTU→carbimazole after 20 weeks; conversion PTU:carbimazole 20:1. May 2026 correction https://obgyn.onlinelibrary.wiley.com/do…

Wockhardt / emc — Propylthiouracil 50 mg tablets — SmPC
· checked 2026-10-17 · verified-live
Open source ↗

Adult 300–600 mg/day initial, then 50–150 mg/day when controlled; renal reductions and hepatic/agranulocytosis warnings. The regimen explicitly distinguishes the general adult range from pregnancy-specific lowest-effective-dose selection in RCOG GTG76.

Manufacturer / emc — Carbimazole tablets — SmPC
· checked 2026-10-17 · verified-live
Open source ↗

Adult 20–60 mg/day initial divided two/three times; 5–15 mg/day maintenance; pregnancy lowest-effective-dose/no block-and-replace, pancreatitis, marrow and hepatic warnings. RCOG supplies pregnancy timing and PTU conversion.

Society for Endocrinology / BTA / ETA joint consensus, Taylor et al. — Management of thyroid emergencies: thyroid storm — 2026 joint consensus
· checked 2026-10-18 · verified-live
Open source ↗

Full open-access primary statement: PTU loading/maintenance, caution with beta-blockade/cardiomyopathy, propranolol 60–80 mg every four hours, hydrocortisone 100 mg load then 50 mg four times/day, iodine at least one hour after thionamide, SSKI five drops four times/day, prompt de-escalation and fai…

NICE — Postnatal care — NG194
· checked 2026-10-18 · verified-live
Open source ↗

Maternal/newborn transfer assessment, first void and effective feeding, handover, support/safeguarding, first midwife visit within 36 hours after transfer, postnatal danger symptoms. Full recommendations page read.

India MoHFW / NHM — District Hospital Standard Operating Procedures — LaQshya
· checked 2026-10-18 · verified-live
Open source ↗

Normal-delivery discharge not less than 48 hours: full primary SOP PDF normal-delivery/discharge passages read. Corroborated by NHM CEmONC 2024 Part 1, chapter 8. This does not define a universal post-caesarean or complicated-case stay.

WHO — WHO recommendations on quality postnatal care — official recommendation summary
· checked 2026-10-18 · verified-live
Open source ↗

Official WHO summary read: at least 24-hour facility care after birth; additional contacts at 48–72 hours, 7–14 days and week 6; individual assessment/support. Summary facts only, not a claim that the full 242-page PDF was reviewed.

RCOG — Laparoscopy — recovering well
· checked 2026-10-18 · verified-live
Open source ↗

Full primary patient recovery page read: pain control, wounds, activity/VTE, urinary/bowel and infection warning signs, adult support and no driving/important decisions during the first 24 hours after general anaesthesia. Used as general recovery/handover principles, not operation-specific discharge…

NICE — Acutely ill adults in hospital — CG50
· checked 2026-10-18 · verified-live
Open source ↗

Full primary recommendations read, focusing on critical-care-to-ward transfer: structured written handover, shared plan, monitoring, rehabilitation and receiving-team capability. Step-down is distinct from home discharge; no universal organ-support discharge cutoff is asserted.