Karleen, I think it was first estimated at 5% by Neifert, Seacat, and Jobe, in this paper: Neifert, M. R., Seacat, J. M., & Jobe, W. E. (1985). Lactation failure due to insufficient glandular development of the breast. *Pediatrics, 76*(5), 823-828. --Diana Cassar-Uhl, IBCLC NY, U.S.A. *********************************************** Archives: http://community.lsoft.com/archives/LACTNET.html To reach list owners: [log in to unmask] Mail all list management commands to: [log in to unmask] COMMANDS: 1. To temporarily stop your subscription write in the body of an email: set lactnet nomail 2. To start it again: set lactnet mail 3. To unsubscribe: unsubscribe lactnet 4. To get a comprehensive list of rules and directions: get lactnet welcome