The umbilical cord should not be cut until pulmonary respiration is established.
The placenta provides the fetus with oxygen, an urgent on-going need.
Transition from fetal to neonatal circulation cannot be expected to always take
place immediately at birth.
Pulsations of the umbilical cord provide evidence that a baby taken from the
womb of its deceased mother is still alive.
Williams Obstetrics, 1950 edition,
Evaluation of respiratory depression in newborns - clamping of the cord
within one minute to preserve the "sterile field" for suturing. "Slow delivery"
was still widely practiced.
Clamp the cord within 30 seconds after birth.
Wait a minute, or two, or more before clamping the cord.