Objective    To evaluate the effects of desamethasone in pregnancy on fetal pituitary-adrenal functions.     Methods    From May 2003 to November 2003 24 cases of intrahepatic cholestasis of pregancy (ICP) in the third trimester were treated with dexamethasone. The levels of ACTH and cortisone in the umbilical blood were detected after delivery. The pregnant Wistar rats were intramuscularly injected of dexamethasone (1 mg·kg

-1

·d

-1

) from the pregnancy day 15 for 5 days as group B

while the rats in group A received no dexamethasone as control group. The levels of ACTH and cortisone of the rat fetus as well as the ACTH in fetal pituitary gland by immunohistochemistry were examined.     Results    The ACTH level in the umbilical blood o

f the fetus increased and the cortisone level decreased as compared to that of the control group. Treatment with desamethasone to pregnant rats resulted in enhanced expression of ACTH

increased serum ACTH concentration

and decreased concentration of cortisol in the rat fetal pituitary gland.      Conclusion    Treatment with dexamethasone in pregnancy causes some impact on the adrenal gland of the newborn rats in the near future.