Respiratory distress syndrome
Reports of respiratory distress syndrome appear to
have increased with more and more widespread
clamping of the umbilical cord sooner and sooner
after birth, though some might credit the pulmonary
problems of premature infants to increased survival.
Moss et al. (1963) investigated the effects of
clamping the cord before the onset of respirations in
129 infants who were premature, delivered by
cesarean section, or born of diabetic mothers [1].
Because the initial gasp of premature infants and
those delivered by cesarean section is often not
strong enough to produce significant expansion of
the lungs, Moss et al. defined "early clamping" of the
cord as that performed before the second breath,
and "late clamping" as that performed after the
second breath. They assigned infants alternately to
groups for early or late clamping of the cord.
The condition of 33 of the 42 premature infants in
the "early clamped" group was depressed (Apgar
scores 0 to 6) Only 13 of the 52 infants in the "late
clamped" group were depressed. Of infants
delivered by cesarean section 4 of 10 in the "early
clamped" group and only 1 of 20 in the "late
clamped" group had Apgar scores in the 0 to 6
range. Two of the 10 c-section infants in the "early
clamped" group developed respiratory distress.
There were 8 deaths among infants weighing less
than 1500 gm, and 6 of these were in the "early
clamped" group. Postmortem examination in the
"early clamped" group revealed pathology of the
lungs, but lung pathology was not found in the 2
infants in the "late clamped" group who died.
Moss et al. pointed out that pulsations in the cord
become progressively weaker and finally cease after
the transition from placental to pulmonary respiration
is complete. This represents a gradual change-over
with only minor alterations in systemic blood flow, but
with sudden occlusion of the cord before expansion
of the alveolar vascular bed, systemic pressure may
cause rupture of capillaries in the lungs, brain, and
other organs. They concluded their paper with the
following comment:
"The carefree manner in which the newly born
infant is 'disconnected' from his 'oxygenator'
without any assurance that respirations will ever
begin is in sharp contrast to the meticulous cre
with which the thoracic surgeon separaes his
patient from the pump-oxygenator." [6, p50]
Moss and Monset-Couchard (1967) four years later
published a review of literature comparing the effects
of early and late clamping of the cord, and begain
with the comment:
"Iatrogenic interruption of the placental
circulation at birth has, in most cases,
become an automatic procedure with little
or no regard for the physiologic alterations
evoked or for their subsequent effect upon
the fetus." [2, p109]
(in progress)
- Moss AJ et al. (1963)
Respiratory distress
syndrome in the newborn.
- Moss AJ, Monset-
Couchard M (1967)
Placental transfusion:
early versus late
clamping of the umbilical
cord.
- Moss AJ, Duffie ER Jr, Fagan LM. Respiratory distress syndrome in the
newborn. Study on the association of cord clamping and the pathogenesis
of distress. JAMA. 1963 Apr 6;184:48-50.
- Moss AJ, Monset-Couchard M. Placental transfusion: early versus late
clamping of the umbilical cord. Pediatrics. 1967 Jul;40(1):109-26.