A unique case of fetal
goiter accompanied by bilateral
ovarian cysts in a mother treated with
methimazole for
Graves'disease is reported. The abnormal findings were detected by ultrasound at 31 weeks of gestation. Umbilical fetal blood sampling revealed elevated serum TSH, normal concentrations of free T 4 , normal FSH and LH and high concentrations of E 2 . A series of weekly amniocenteses and intra-amniotic
injections of
levothyroxine was initiated, along with a reduction of the mother's
methimazole dosage. The level of TSH in amniotic fluid was initially high, but was considerably reduced by each injection and followed by a gradual reduction of fetal
goiter as well as the left
ovarian cyst. The right
cyst ruptured spontaneously. At 36 weeks + 4 days, the patient underwent elective
caesarean section and gave birth to a female, weighing 2,880 g with 1- and 5-min Apgar scores of 10. The thyroid gland appeared normal in size, and cord blood TSH and free T 4 were both within normal limits. At ultrasound control 6 days later, the right
ovarian cyst was not visible, while the left
cyst was still present. Thus, our report supports previous findings that fetal
goiter can be treated successfully with intra-amniotic injection of
levothyroxine.More importantly, it shows that fetal
hypothyroidism with elevated levels of TSH can be accompanied by
ovarian cysts,suggesting interference between thyreotropic and gonadotropic
hormones.