Pregnancy complicated by multiple endocrine neoplasia type IIA (Sipple's syndrome).

A patient with preexisting multiple endocrine neoplasia type IIA had normal 24-hour urinary metanephrine and vanillylmandelic acid excretions before and during pregnancy. After a benign prenatal course, the patient had a term spontaneous vaginal delivery. Multiple endocrine neoplasia type IIA antedating pregnancy may be associated with a normal obstetric outcome in the absence of a phenochromocytoma.