Endocrine Abstracts

A 36-year-old woman was admitted with newly diagnosed Grave’s disease due to significant symptoms. Blood results revealed fT4 83.2 (pmol/l) TSH <0.01 (mIU/l), and TSH Receptor Antibody 4.56 (0-0.4 U/l)). She was commenced on Propylthiouracil (PTU) thrice daily alongside Propranolol. She had a blood test in 4 months’ time, when she was 5 weeks pregnant. Blood results suggested profound hypothyroidism with fT4 4.7 (pmol/l) and TSH 82.02 (mIU/l), and she was commenced on 75 mcg Levothyroxine/day. She and her partner were counselled on the potential adverse effects of hypothyroidism during early pregnancy, and they decided to continue with the pregnancy. At 9 weeks gestation, the patient reported palpitations and tremors, and was tachycardic on examination. Blood tests revealed fT4 20.4 (pmol/l) and TSH 0.06 (mIU/l). Levothyroxine was stopped and she was re-commenced on 50 mg PTU/day due to sustained symptoms. PTU was stopped at 15 weeks gestation as TFTs were within normal limits and she remained clinically euthyroid. Anomaly scan at 20 weeks reported no congenital abnormalities, foetal goitre or tachycardia. The patient underwent an elective C-section at 39 weeks for a history of previous C-sections. No intrapartum or postpartum complications were noted. APGAR score was 9,10,10, and the baby’s birth weight was 3860g (82.8 centile). At a clinic review at 9 months post-partum, the patient was clinically euthyroid with TFTs within normal limits. At 16 months post-partum, she reported no developmental or behavioural concerns with her baby. As hypothyroidism was detected early in the pregnancy, this allowed for prompt initiation of treatment with thyroxine, which may have contributed to the positive outcome. Clinicians and midwives should be aware of the importance of pre-conception counselling and TFT monitoring prior to pregnancy in patients with known thyroid disease.