title: Management of congenital adrenal hyperplasia during pregnancy.
abstract: OBJECTIVE
  To provide an overview of the congenital adrenal hyperplasias (CAHs) and their management during pregnancy.
  
  
  METHODS
  Pathways of steroid biosynthesis and inherited deficiencies of required enzymes are reviewed, and applications to prenatal diagnosis and treatment of affected fetuses are discussed.
  
  
  RESULTS
  The CAHs are a group of inherited enzymatic defects of adrenal steroid biosynthesis. During pregnancy, maternal problems are confined to women with 21-hydroxylase deficiency, 11b-hydroxylase deficiency, and 3b-hydroxysteroid dehydrogenase deficiency because other adrenal enzyme deficiencies are incompatible with fertility. The interposition of the placenta on the hypothalamic-pituitary-adrenal axis has a major effect on clinical evaluation of CAH during pregnancy. Women with severe forms of CAH have decreased fertility rates because of oligo-ovulation, and successful conception requires a combination of good therapeutic compliance, careful endocrine monitoring, and often induction of ovulation. 21-Hydroxylase deficiency in the fetus can now be diagnosed accurately prenatally by endocrine testing and molecular genetic techniques. Prenatal diagnosis of 11b-hydroxylase deficiency in the fetus by endocrine testing is not as sensitive. Prevention of masculinization of affected female fetuses by corticosteroid suppression has been attempted in both 21-hydroxylase deficiency and 11b-hydroxylase deficiency CAH, with variable degrees of success. To date, no reports have been published of prenatal diagnosis or treatment of affected female fetuses with 3b-hydroxysteroid dehydrogenase deficiency CAH.
  
  
  CONCLUSIONS
  Endocrine and genetic studies of CAH during pregnancy have improved the diagnosis and management.
authors.affiliation: Department of Obstetrics and Gynecology, University of Ottawa, Ottawa Civic Hospital, Ontario, Canada.
authors.forename: P R
authors.initials: PR
authors.lastname: Garner