Suppressed levels of growth hormone and insulin-like growth factor-1 during successful pregnancy in persistent acromegaly

Pregnancy is a rather rare event in acromegaly because fertility is often reduced during active disease. Previous reports of pregnancy in acromegalic patients showed that the pituitary growth hormone (OH) level was unaffected and the insulin-like growth factor (IGF)-1 level was elevated during the second and third trimesters. We describe here a case of persistent acromegaly that showed suppressed levels of OH and IGF-1 during pregnancy. The suppression of OH secretion and IGF-1 may be due to increased estrogen or other factors circulating in mid- to late pregnancy.