Successful pregnancy in an infertile woman with a thyrotropin-secreting macroadenoma treated with somatostatin analog (octreotide).

Somatostatin analogs are an alternative medical treatment in patients with TSH-secreting pituitary adenoma. A 31-yr-old infertile woman with a TSH-secreting macroadenoma was treated with continuous sc infusion of 300 micrograms octreotide/day. After 3 months, euthyroid status was restored, and pituitary magnetic resonance imaging showed a reduction of the macroadenoma. Subsequently, the patient was found to be pregnant, and octreotide was stopped after 1 month of gestation. Serum TSH and free thyroid hormone concentrations returned to pretreatment values. At 6 months of pregnancy, a visual field examination was abnormal, and a magnetic resonance imaging scan showed an enlargement of the pituitary adenoma. Reinstitution of octreotide treatment was associated with normalization of TSH and free thyroid hormone concentrations, a rapid improvement of visual fields, and a new reduction in the size of pituitary macroadenoma. Octreotide treatment was continued until an elective cesarean section was performed at 8 months gestation. Despite the presence of immunoreactive octreotide in the umbilical cord, neonatal thyroid parameters were normal, and a physiological rise in TSH with the increase in thyroid hormone concentrations occurred in the neonate. In conclusion, 1) octreotide treatment is effective in controlling TSH-secreting macroadenoma during pregnancy; 2) despite the transplacental passage of immunoreactive octreotide, physiological changes in thyroid parameters occur in the neonate, and 3) exposure of the fetus to octreotide during the first month as well as the last trimester of gestation did not induce any malformation or affect fetal development.