Thyroid Problems in Preganancy

Thyroid problems in pregnancy are reasonably common. Inability to conceive is one of the main presentations where thyroid dysfunction is diagnosed in the childbearing age. Patients with known primary hypothyroidism can safely plan pregnancy while on replacement. Dose requirement will increase in pregnancy. Thyroid function should be checked at least three times during pregnancy: 12-14, 24-26 and 32-34 weeks (Box-1). Particular care should be taken to monitor the biochemical state in pregnancy because the clinical symptoms and signs of mild hypo-and hyper-thyroidism can be difficult to pick up in pregnancy. Graves’ disease diagnosed during pregnancy needs careful monitoring6. Due consideration should be given for foetal thyroid state. The clinical indicators for foetal Graves’ disease (prevalence is one in 1000 of mothers with active Graves’ disease) are low or high foetal heart rate (<120 or >160 per min, respectively), poor foetal growth on ultrasonography and presence of foetal goitre. Routine foetal cord blood sampling is not indicated. Heel prick for TSH for babies born with or without thyroid disease is a routine in most of the world including ours.

Postpartum thyroiditis is a distinct entity when previously well woman presents with thyroiditis after delivery. It can present anytime within the first year and commonest presentation is with hypothyroidism.

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