From 1976 to 1986, 204 procedures were performed, 98 using forms of anesthesia in rats, dogs, cats, rabbits, sheep, and monkeys. We began with the complete laparotomy, complete hysterectomy, considerable mobilization of the uterus and minimal fetal mobilization. The technique was improved to minimal laparotomy, minimal hysterectomy, extensive mobilization of the fetus and minimal mobilization of the uterus. At last, the fetal survival rate was improved to approximately 80% and maternal survival to 100%. The fetal procedures were: catheters to the aorta, cava, allantois, and amniotic cavity; EEG electrodes; dissection of the hypophysis, pyeloamniostomata for correction of nephropathies; study of wound healing of the skin, muscle, and cartilage.