Introduction: Congenital goiter is a rare condition which can be associated with both fetal hyper- and hypothyroidism. It may result from different situations in maternal-fetal thyroid function because antithyroid medication, iodine as well as stimulatory and inhibitory antibodies readily cross the placenta. Aim of the study is the presentation of a newborn infant with congenital goiter and neonatal thyroid suppression that could be attributed to either an in utero exposure to antithyroid drug - propylthiouracil (PTU) or mother´s blocking antibodies.
Case report: Full term neonate was born with enlarged thyroid and signs (laboratory findings) of congenital hypothyroidism. The mother was treated due to hyperthyroidism between 8 and 12 week of pregnancy and presented thyroid-stimulating immunoglobulins (TSI) after delivery. During the treatment with replacement doses of L-thyroxin in infancy period no thyroid antibodies in the child were detected.
Conclusions: The most probable reason was the negative influence of PTU: very high thyroid stimulating hormone (TSH) level since delivery and goiter development indicate that fetal hypothyroidism had been developing for a long time.