A Case of Dichorionic Twin Pregnancy with Maternal Propylthiouracil Induced Hypothyroid Goiter in Both Fetuses Treated with Intramniotic Levothyroxine

Abstract

Fetal hypothyroid goiters are observed in 1:40,000 births. They are usually attributed to underlying thyroid glandular dysgenesis, dyshormonogenesis, or an adverse effect of maternal anti-thyroid drugs. The objective of the present case report is to outline the details of a twin gestation with hypothyroid goiter in both fetuses managed by intramniotic levothyroxine administration. The index pregnancy was of dichorionic twin gestation in which the mother was receiving oral propylthiouracil. Fetal goiters were first detected in ultrasound performed at 31 weeks of gestation. The hypothyroid nature of goiters was confirmed by cordocentesis from both sacs. Intramniotic administration of 100 μg of levothyroxine into both sacs was performed twice at the interval of two weeks. The response to treatment was assessed by amniotic fluid thyroid hormone levels, and serial measurement of thyroid gland volume. Emergency cesarean section was performed at 35 weeks due to preterm labor. Both fetuses were euthyroid at birth and were discharged in good health.

SFM Fetal Therapy Practice Guidelines: Fetal Medical Therapy

“…Surveillance of treatment response should be done by serial fetal thyroid volume measurement and estimation of amniotic fluid thyroid-stimulating hormone (TSH) and free T4 levels. 9…”