Endocrine Abstracts

Background: Nottingham University Hospitals (NUH) has a joint endocrine/antenatal clinic to manage autoimmune hyperthyroidism in pregnancy, with the aim of close monitoring and management.

Aim: To review service according to NUH standards (Pregnant Women with Thyroid Dysfunction):

1. At 20 weeks if thyrotoxic/on antithyroid drugs (ATD)/post radio-iodine or surgery, check thyrotropin receptor autoantibodies (TSHRAb).

1. If >3x upper limit of normal (ULN), arrange foetal monitoring

2. At 30 weeks repeat TSHRAb if previously >3xULN and continue foetal monitoring

2. Check thyroid function test (TFT) every 4 weeks when on ATD, using lowest dose to maintain TFT normal/borderline high.

3. Inform neonatologists if TSHRAb≥1.0 IU/l.

4. Check TFT at 6 weeks.

Results: Between April 2019-March 2021, 33 patients were seen in endocrine/antenatal clinic with a diagnosis of autoimmune hyperthyroidism.

1. All patients (33/33 100%) had TSHRAb antibodies measured in 2nd trimester.

1. 6 patients had raised TSHRAb antibodies (>3xULN). 100% of these had foetal monitoring.

2. All patients with raised TSHRAb antibodies continued to have foetal monitoring in 3rd trimester. 3/6 patients had TSHRAb antibodies remeasured in 3rd trimester (1 premature birth).

2. 17/33 patients were on ATD in their pregnancy. 11/17 continued on ATD throughout pregnancy. 100% of these patients had TFT checked roughly every 4 weeks and were on lowest dose to maintain TFTs normal/borderline high.

3. All babies born to patients with raised TSHRAb antibodies (6) had TFTs checked in neonatal period as neonatologists were informed. 1/6 of these babies had neonatal thyrotoxicosis.

4. 25/32 had 6 week TFT check (1 patient OOA). Of the 7 not checked, 5 were documented in clinic letters for GP to do so.

Conclusion: The standards laid out in the clinical guideline are followed in clinical practice in the joint antenatal/endocrine thyroid clinic.