Endocrine Abstracts

Background: In the first trimester, the foetus is dependent on circulating maternal thyroid hormones for normal brain development. Maintenance of euthyroidism is important throughout pregnancy and maternal hypothyroidism is associated with adverse foetal outcomes.

Aim: To audit the management of pregnancies complicated by hypothyroidism in a joint antenatal endocrine clinic in comparison with the UK guidelines from the British Thyroid Association (2006).

Methods: Retrospective case notes analysis of 65 women with hypothyroidism attending the antenatal endocrine clinic in 2007 (includes 1 patient diagnosed at 16 weeks gestation).

Results: Of 64 patients, 25 (39%) had TSH measured in the pre-conception period and 16 (25%) were within the recommended range. Forty-five (70%) patients had TSH measured at diagnosis of pregnancy and 18 (28%) were in range. All 65 patients had a TSH assay at the antenatal booking visit and 26 (40%) were in range. Fifty-five (86%) patients had a TSH assay in the third trimester and 47 (73%) were in range. Initial visits to the antenatal clinic were at median gestation of 16 weeks. Median number of clinic visits was 3. Thirteen patients (20%) remained on the same dose throughout pregnancy. Forty-three (66%) women had their thyroxine dose titrated at the initial antenatal clinic or later. Nineteen (29%) patients had a postpartum TSH assay.

Conclusions: This audit suggests sub-optimal management of hypothyroidism in the pre-conception and early phases of pregnancy. Primary-care physicians should feel empowered to optimise thyroxine treatment in the pre-conception phase and when pregnancy is confirmed, as the first review with the obstetrician and endocrinologist is currently early in the second trimester. The audit suggests satisfactory measurement of TSH at antenatal booking and subsequent trimesters. Management of hypothyroidism during pregnancy requires a unified approach between general practitioners and hospital specialists.