July 2004
5
Hypovolemic
shock
labor has resulted in a number of
infants whose respiratory efforts are sluggish at birth and whom the obstetrician wishes to Turn
over immediately to an assistant for aspiration of mucus and, if necessary, resuscitation. This readily leads to the habit of clamping all cords
promptly. Secondly, there is the episiotomy wound to
suture; and the quicker the repair is started, the shorter will be the duration of anesthesia, and the
less the blood loss from the wound.
Finally, modern management of the third stage, especially if ergonovine has been given with the birth of the
anterior shoulder, calls for immediate attention to the uterus and furnishes another reason for handing the
baby to an assistant or nurse as promptly as possible. These three tendencies of modern obstetrics,
then, notwithstanding
their several merits, do militate against delayed clamping of the cord." – Eastman 1950, pp397-398 [55].
Efforts to minimize jaundice
became another
impetus for clamping the umbilical cord early, even after the cause of maternal-infant Rh-factor incompatibility
was understood,
and exchange-transfusion and RhoGam treatments available [27, 56]. Opinion, not evidence, appears to have led to recruitment of many adherents
to this "school
of thought" [7].
5. Hypovolemic shock
Waiting for the infant to cry is
no doubt
instinctive for most obstetricians and midwives before clamping the
cord. However, recently developed
delivery-room protocols state that the cord should be clamped immediately [57]. This protocol has found its way into several recent
textbooks [58-62]. If followed too literally, clamping of the cord before the first breath
could not only
obstruct the shift of placental blood to the lungs, but also leave the
infant in a state of hypovolemic shock.
Reports on transfusions and blood volume expanders needed for infants in neonatal
intensive care units indicate that hypovolemia may not be an infrequent problem [7,
63].
Most infants do breathe within seconds of birth, but as Dunn [8]
pointed out,
"There is often a delay after delivery before breathing
commences." Continuing pulsation of the umbilical cord
stump was observed
in newborn infants and correlated with early respiratory distress by Desmond and coworkers in 1959 [64]. The lungs, not the amputated placenta, should
become the
