ESPE Abstracts

Background: Neonates born from mothers with Graves’ disease are at risk to develop hyperthyroidism due to placental transmission of TSH-receptor antibodies. Neonatal hyperthyroidism should be effectively diagnosed and treated to prevent severe complications of this disease (cardiac symptoms, poor weight gain, severe neurological manifestations).

Objectives: To describe the post-natal follow-up of neonates born from women with Graves’ disease.

Method: 33 neonates (17 ♀, 52%), born from 32 women (1 twin pregnancy) with Graves’ disease diagnosed before (n=23) or during pregnancy (n=9) referred to our hospital between 2006 and 2015 were included in this study. Symptoms of hyperthyroidism, thyroid function tests, TSH-receptor antibodies (TRAK) titers were collected during the follow-up. Data are reported in median [Q1–Q3] values.

Results: Seven women (22%) have had thyroïdectomy and/or IRA therapy. During pregnancy, 24 women (75%) were treated with anti-thyroid drugs (21 received PTU). Maternal TRAK titers were available in only 22 (68%) women at the last trimester of pregnancy or at birth and were positive in 21 (95.5%, TRAK: 15 [3.5–35] UI/l). At birth, gestational age was 38 [37–39] weeks, seven neonates were born preterm and 3 were SGA. 3 neonates had birth defects (hexadactily, biventricular dilatation, unilateral kidney hypoplasia+ureteral duplicity). 14 neonates had goiter and 2 exophthalmia. 25/31 neonates (80.6%, 2 missing data) were TRAK+ within the first 10 days. During the post-natal follow-up: 15 newborns did not require ATD. Their thyroid function tests at 3–5 post natal days were: TSH: 3[1.2–5.7] mU/l, FT4: 26.8 [15.5–30.6] pM/L, FT3: 6.6 [6.3–8.1] pM/l, TRAK:6.8[2.2–10.9]UI/l. Among them, three neonates developed central (n=1) or primary (n=2) hypothyroidism and were treated with L thyroxin within the first post-natal month. 18 neonates (54.5%) had overt hyperthyroidism (TSH: 0.1 [0.0–0.9] mU/L. FT4: 50 [37–54] pM/L. FT3: 11.6 [10.0–13.0] pM/L, TRAK: 12[6–35] UI/l) requiring treatment. Carbimazole was initiated at the age of 4.5 [3.0; 8.0] days, at a baseline dose of 0.8 [0.6–1.0] mg/k/d for a duration of 1.9 [1.3–2.5] months. 10 babies received beta-blockers and 7 combined treatment with L-Thyroxin. Treatment was well tolerated. Craniostenosis was observed in 1 neonate.

Conclusion: Repeating thyroid function tests in the first postnatal weeks was effective to detect hyper or hypothyroidism in neonates born from mothers with Graves disease. ATD was well-tolerated and effective to protect infants from the severe consequences of thyrotoxicosis.