The lowest uncorrected premature infant mortality rate reported has been attained at the St. Louis Maternity Hospital during a recent three and one-half year period because of the protective effect of conduction (continuous caudal or saddle block) analgesia and anesthesia. This study has been made with the cooperation of the Departments of Obstetrics and Pediatrics of the Washington University School of Medicine, and the results of these joint efforts are of major importance in the field of obstetric anesthesia. From July 10, 1945 until Dec. 27, 1948, 3,000 labors and deliveries were completed with the use of conduction anesthesia. Of the 3,000 patients in labor, 2,500 received caudal and 500 saddle block anesthesia. The conduction anesthesia series consisted of 28.2 per cent of the 10,640 deliveries that occurred during the control period. This series included 631 premature infants, an incidence of 5.9 per cent. This figure agrees generally with those