Thyroid Disease in Pregnancy
The guidelines recommend management of common obstetric conditions at primary and referral level, based on local experience and evidence-based practice. They are not intended as strict protocols nor as standard operating procedures, but rather as a guide to safe effective management of common obstetric problems. The guidelines should be most useful to interns, medical officers and registrars.
Most pregnant women with thyroid disease are already on treatment when they present for antenatal care. Women with recent onset of goitre, thyroid nodule, or with clinical evidence of thyroid dysfunction require investigation in consultation with specialist endocrinologists. Pregnant women with thyroid disease are best managed in a combined obstetric/endocrine clinic
Hyperthyroidism
- Most cases are diagnosed as autoimmune Graves’ disease
- Antithyroid drugs (carbimazole) are effective in controlling hyperthyroidism
- Monitor thyroid functions regularly throughout the pregnancy
- Ensure that the maternal haemoglobin is ≥11 g/dL
- Follow the fetus with ultrasound scans to detect goitre or growth restriction
- Mode of delivery should be dictated by obstetric considerations
- Inform the anaesthetists of a planned caesarean section
- Inform the paediatricians that the woman is hyperthyroid – take cord blood at delivery for TSH &T4
- Beware of postnatal exacerbations of hyperthyroidism
- The most serious maternal complications are thyroid storm & heart failure
Hypothyroidism
- Most cases have had thyroid gland destruction caused by autoimmune disease (Hashimoto’s thyroiditis), surgery or radiation
- Thyroid hormone replacement is effective & safe in pregnancy
- Expect normal pregnancy and delivery in well controlled patients
- Beware of postnatal exacerbations of hypothyroidism
- The most serious maternal complication is myxoedema coma