[Congenital adrenal hyperplasia and pregnancy]

About 90% of CAH cases are due to 21-hydroxylase (21-OH) deficiency. There are decreased cortisol and increased ACTH secretions; and elevated cortisol precursors and androgens. CAH is an important factor of menstrual disorders and infertility. Pregnancy is very much uncommon in the classic form, and 90% of reported cases belong to the postnatal form. The authors present two patients with classic form of CAH (21-OH deficiency) who became pregnant. They had been treated in early childhood (2-4 years old) with glucocorticoids and had surgical correction of the ambiguous external genitalia. During pregnancy, daily prednisone dose was raised to 5 mg twice, serum levels of 17-hydroxyprogesterone (17-OHP) and androgens were monthly measured. The 17-OHP levels remained high (about 1.6 ng/dl), and androgens (testosterone, androstenedione, SDHEA) levels remained normal. Cesarean section was performed in both cases; newborns were normal and 17-OHP was within normal limits. Adequate early replacement therapy has improved fertility and pregnancy.