Chiari-Frommel syndrome /kē·är″ēfrom″əl/ [Johann B. Chiari, German obstetrician, 1817–1854; Richard Frommel, German gynecologist, 1854–1912] , a hormonal disorder that occurs after pregnancy in which weaning does not spontaneously end lactation. It is usually the result of a decrease in pituitary gonadotropins and an excess of pituitary prolactin and may be accompanied by amenorrhea. Treatment includes observation, hormonal therapy, and investigation to confirm or rule out pituitary tumor.