HISTORY OF UMBILICAL CORD CLAMPING
By the 1950s, standard practice was 1 minute for ‘early’ and 5 minutes for ‘late’ clamping. Current practice of immediate clamping was based on series of blood volume studies in the 1960s by John Lind in Sweden, William Oh and Alice Yao in the United States, and Robert Usher from Canada. These authors concluded that ‘early’ cord clamping should occur within 15 seconds of delivery and that ‘late’ clamping could be as early 1 minute. Immediate clamping was promoted on the basis of the conclusion the 90% of blood volume was achieved within the first few breaths after delivery. In addition, obstetricians vegan practicing active management of the third stage of labor to reduce to reduce postpartum hemorrhage. This included the administration of a prophylactic uterotonic agent, clamping and cutting the umbilical cord shortly after birth, and controlled traction of the umbilical cord. Studies began to show that early clamping also reduced polycythemia and jaundice. Consequently, cord clamping began to be performed within 15 to 20 seconds of the infant being born, within the infant maintained at or below the level of the placenta.