Endocrine Abstracts

Until 12th week of gestation foetus is entirely dependent on maternal thyroxine. Inadequate thyroxine replacement may lead to lower IQ of offspring and also an increased miscarriage rate.

We audited 68 hypothyroid pregnant females to assess whether management of their thyroid status had met current standards. In the first trimester TSH is not an optimal monitoring marker as it is supressed by rising HCG level. According to established clinical guidelines FT4 should be maintained in the upper limit of normal and TSH less than 2.5 mIU/l in the first trimester by appropriately adjusting the dose of levothyroxine.

Sixty-eight hypothyroid pregnant patients presenting in 2012 to Mid-Yorkshire Trust, UK, were identified using the Euroking database and hospital records. Only 49% (33/68 patients) had the thyroid function tests checked by 8th week of gestation to allow sufficient time for adjustment of levothyroxine dosage if required. 18/33 patients required no dose adjustment, 9/33 patients had the dose of thyroxine appropriately increased, 6/33 patients should have had thyroxine dose increased but no adjustment had been made. Of 23/68 patients first tested after 12 weeks gestation, 10 should have had thyroxine increased suggesting the foetus had been put at risk during first trimester.

Only 40% (27/68 patients) actually met the standards of monitoring and dose adjustment, if required, in a timely manner. In order to improve care in line with established clinical standards education of patients and GP practises need to be improved by circulating audit results to GPs and making hypothyroid female patients aware of the need to have their thyroid function tests checked as soon as they become pregnant. We are planning to re-audit in 1 year time to see if compliance with guidelines has been improved.