PREVENTION of premature births is the most important challenge in obstetrics. Recently a device for monitoring uterine activity at home (the Genesis Home Uterine Activity Monitor [HUAM] system, Tokos Medical Group), coupled with daily contact between patients and medical personnel, was reported to prevent premature births at an average cost per patient of over $5,000.1 The Food and Drug Administration recently approved this system for the early detection of preterm labor in women who had had a previous preterm delivery. The agency did not approve this system of care for the prevention of premature births, however, and has made it. © 1991, Massachusetts Medical Society. All rights reserved.