Short-term hyperthyroidism followed by transient pituitary hypothyroidism in a very low birth weight infant born to a mother with uncontrolled Graves' disease

Citation
R. Higuchi et al., Short-term hyperthyroidism followed by transient pituitary hypothyroidism in a very low birth weight infant born to a mother with uncontrolled Graves' disease, PEDIATRICS, 107(4), 2001, pp. NIL_85-NIL_87
Citations number
6
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Pediatrics,"Medical Research General Topics
Journal title
PEDIATRICS
ISSN journal
0031-4005 → ACNP
Volume
107
Issue
4
Year of publication
2001
Pages
NIL_85 - NIL_87
Database
ISI
SICI code
0031-4005(200104)107:4<NIL_85:SHFBTP>2.0.ZU;2-J
Abstract
Transient hypothyroxinemia in infants born to mothers with poorly controlle d Graves' disease was first reported in 1988. We report that short-term hyp erthyroidism followed by hypothyroidism with low basal thyroid-stimulating hormone (TSH) levels developed in a very low birth weight infant born at 27 weeks of gestation to a noncompliant mother with thyrotoxicosis attributab le to Graves' disease. We performed serial thyrotropin-releasing hormone (T RH) tests in this infant and demonstrated that TSH unresponsiveness to TRH disappeared at 6.5 months of age. The maternal thyroid function was free triiodothyronine (FT3), 21.1 pg/mL; free thyroxine (FT4), 8.1 ng/dL; TSH, <0.03 <mu>U/mL; thyroid-stimulating h ormone receptor antibody, 52% (normal: <15%); thyroid-stimulating antibody, 294% (normal: <180%); and thyroid-stimulation blocking antibody, 9% (norma l: <25%) on the day of delivery. A nonstress test revealed fetal tachycardi a >200 beats per minute, and a male infant weighing 1152 g was born by emer gency cesarean section. Thyroid-stimulating hormone receptor antibody was 1 6% and thyroid-stimulating antibody was 370% in the cord blood. We administ ered 10 mg/kg per day of oral propylthiouracil from day 1. Tachycardia alon g with elevated FT4 and FT3 levels in the infant decreased from 200/minute to 170/minute, 4.7 ng/dL to 2.9 ng/dL, 7.0 pg/mL to 4.8 pg/mL, respectively , in the first 33 hours. At 5 days, FT4 and FT3 were 1.1 ng/dL and 2.9 pg/m L, respectively, and we stopped propylthiouracil administration. Although F T4 decreased to 0.4 ng/dL, TSH was quite low and did not respond to intrave nous TRH by 14 days of age. We began daily levothyroxine 5-mu /kg supplemen tation. The responsiveness of TSH to TRH did not become significant until 4 months old and normalized at 6.5 months old. At this time, levothyroxine w as stopped. We conclude that placental transfer of thyroid hormones may cause hyperthyr oidism in the fetal and early neonatal periods and lead to transient pituit ary hypothyroidism in an infant born to a mother with uncontrolled Graves' disease.