e The availability of insulin since 1922, restored fertility and virtually abolished maternal mortality. At the same time, perinatal survival did not change appreciatably Since 1949 White Classification was developed, permitted individualized timing and mode of delivery, then perinatal mortality was reduced (nearly equivalent to that observed in normal pregnanciesThe availability of insulin since 1922, restored fertility and virtually abolished maternal mortality. At the same time, perinatal survival did not change appreciatably. Since 1949 White Classification was developed, permitted individualized timing and mode of delivery, then perinatal mortality was reduced (nearly equivalent to that observed in normal pregnancies.)