Background: Neonatal Graves disease (NGD) occurs in 12% pregnancies with maternal Graves disease. Thyroid auto-antibodies can persist in the maternal circulation even 10 years after thyroidectomy and can lead to NGD in the absence of maternal thyrotoxicosis. Both maternal stimulating autoantibodies and maternal thyroxine can cross the placenta, and have been implicated in neonatal craniosynostosis.
Objective and hypotheses: We report a case of NGD associated with craniosynostosis in a baby of a 33 year old female with a history of Graves disease. She underwent a total thyroidectomy prior to the pregnancy and was started on suppressive doses of thyroxine therapy for incidentally detected papillary carcinoma of the removed thyroid.
Method: During the pregnancy, which was unplanned, mother had poor antenatal clinic attendance and continued to take 200 μg of thyroxine daily. Baby was delivered by emergency section at 32 weeks of gestation, due to fetal distress. Birth weight was 1.7 kg and there was no goitre. Baby had tachycardia from birth and developed proptosis, diarrhoea and high blood pressure on day 5.
Results: On day 2, TSH was low [0.005 mIU/l (120)] but f T4 was normal [4.6 ng/dl (25)]. By day 5, fT4 increased to 5.4 ng/dl (0.92.2). The baby was treated with carbimazole 0.5 mg/kg/d and propranolol. He showed clinical improvement, and normalisation of ft4 within 5 days. Carbimazole was gradually discontinued over 3 months and child remained euthyroid. However, he had poor cranial growth post-natally, and at 9 months, his anterior fontanel had closed completely, and he had microcephaly and developmental delay.
Conclusion: In this unusual case of NGD, both maternal stimulating autoantibodies and high dose thyroxine therapy could have potentially contributed to development of craniosynostosis and microcephaly. It is important be vigilant of past autoimmune thyroid disease during pregnancy, and monitor the fetus and new-born accordingly.
10 Sep 2016 - 12 Sep 2016