From the Department of Gynecology and Obstetrics, St. Louis University School of Medicine and St. Mary's Hospital, St. Louis, Mo.

Appreciation is expressed to D. Cavanagh, M.D., Professor and Chairman of the Department of Obstetrics and Gynecology, for helpful criticism and suggestions given in the preparation of this paper, and to the obstetric staff of St. Mary's Hospital for supplying donors and for encouraging their patients to participate in this program.

Submitted for publication July 17, 1967.