1. Ardran GM et al. (1952) The
    effect of ventilation of the
    foetal lungs upon the
    pulmonary circulation.
  2. Dawes GS et al. (1953a)
    Changes in the lungs of the
    new-born lamb.
  3. Dawes GS et al. (1953b) The
    patency of the ductus
    arteriosus after birth.
  4. Dawes GS et al. (1953c) The
    closure of the foramen ovale
    after birth.
  5. Born GV et al. (1954)
    Changes in the heart and
    lungs at birth.
  6. Dawes GS et al. (1955) The
    patency of the ductus
    arteriosus in newborn lambs
    and its physiological
    consequences.
  7. Burnard ED (1958) A murmur
    from the ductus arteriosus in
    the newborn baby.
  8. Burnard ED (1959a) The
    cardiac murmur in relation to
    symptoms in the newborn.
  9. Burnard ED (1959b)
    Changes in heart size in the
    dyspnoeic newborn baby.
  10. Burnard ED, James LS
    (1963) Atrial pressures and
    cardiac size in the newborn
    infant. Relationships with
    degree of birth asphyxia and
    size of placental transfusion.
  11. Burnard ED, James LS
    (1963) Atrial pressures and
    cardiac size in the newborn
    infant. Relationships with
    degree of birth asphyxia and
    size of placental transfusion.
  12. Merkle EM, Gilkeson RC
    (2005).Remnants of fetal
    circulation: appearance on
    MDCT in adults.
  13. Link to Children's Hospital
    Boston page on patent
    ductus arteriosus.
  14. Morley GM (2002) Why Do
    Babies Cry.
  1. Ardran GM, Dawes GS, Prichard MML, Reynolds SRM, Wyatt DG. The
    effect of ventilation of the foetal lungs upon the pulmonary circulation. J
    Physiol 1952 Sep 26; 118(1), 12-22. http://jp.physoc.
    org/cgi/reprint/118/1/12
  2. Dawes GS, Mott JC, Widdicombe, JG, Wyatt DG. Changes in the lungs of
    the new-born lamb. J Physiol. 1953 July 28; 121(1): 141–162.
  3. Dawes GS, Milne ED, Mott JC, Widdicombe JG (1953) The patency of the
    ductus arteriosus after birth. J Physiol. 1953;122(suppl):37P-38P.
  4. Dawes GS, Milne ED, Mott JC, Widdicombe JG.The closure of the foramen
    ovale after birth. J Physiol. 1953;122(suppl):38P....................................
    http://jp.physoc.org/cgi/reprint/122/Suppl/1P
  5. Born GV, Dawes GS, Mott JC, Widdicombe JG. Changes in the heart and
    lungs at birth. Cold Spring Harbor Symposia on Quantitative Biology 1954;
    19:102-8.
  6. Dawes GS, Mott JC, Widdicombe JG. The patency of the ductus arteriosus
    in newborn lambs and its physiological consequences. J Physiol. 1955 May
    27;128(2):361-83. http://jp.physoc.org/cgi/reprint/128/2/361.pdf
  7. Burnard ED. A murmur from the ductus arteriosus in the newborn baby. Br
    Med J. 1958 Apr 5;1(5074):806-10.
  8. Burnard ED. The cardiac murmur in relation to symptoms in the newborn.
    Br Med J. 1959 Jan 17;1(5115):134-8.
  9. Burnard ED. Changes in heart size in the dyspnoeic newborn baby. Br Med
    J. 1959 Jun 13;1(5136):1495-500. ..............................................................
    http://www.pubmedcentral.nih.gov/picrender.fcgi?
    artid=1993728&blobtype=pdf
  10. Burnard ED, James LS. Atrial pressures and cardiac size in the newborn
    infant. Relationships with degree of birth asphyxia and size of placental
    transfusion. J Pediatr. 1963 Jun;62:815-26.
  11. Burnard ED, James LS. Atrial pressures and cardiac size in the newborn
    infant. Relationships with degree of birth asphyxia and size of placental
    transfusion. J Pediatr. 1963 Jun;62:815-26.
  12. Merkle EM, Gilkeson RC.Remnants of fetal circulation: appearance on
    MDCT in adults. AJR Am J Roentgenol. 2005 Aug;185(2):541-9.
  13. Link to Children's Hospital Boston page on patent ductus arteriosus ......
    http://www.childrenshospital.org/az/Site507/mainpageS507P0.html
  14. Morley GM (2002) Link to cordclamp.com website -- click on "Why Do
    Babies Cry"
Cardiac murmur and patent ductus arteriosus
Experiments with sheep conducted by Dawes and
co-workers during the 1950s are cited as providing
evidence that the ductus arteriosus begins to
constrict with spontaneous respiration or positive
pressure ventilation of the lungs, but that it normally
remains open for several hours following birth [1-6].  
They described a "neonatal circulation" intermediate
in type between that of the fetus and adult.  The
umbilical cord was tied in most of their experimental
animals at varying times before or after ventilation.  
The tradition of "slow birth" and waiting for pulsations
to cease before cutting the cord appears to have
lost favor during the 1950s, while ligation became
more and more the standard thing to do.

Burnard (1958, 1959) reported cardiac murmurs
from blood flow through a persistent ductus
arteriosus to be more common in infants with a delay
of three minutes or more in establishing normal
breathing after birth. [7, 8].  He also reported a
finding of enlarged hearts in affected babies [9].  
Burnard later worked with Apgar and James, and
published a paper with James on enlargement of the
heart in infants who suffered asphyxia [11].  In some
of the infants in this study, placental transfusion was
allowed or even promoted by stripping the cord.  The
conclusion was carefully couched in terms that would
not negate the policy of clamping the umbilical cord
within a minute after birth, the protocol used by
Apgar and James for more than a decade.

Now more than 50 years after routine clamping of
the umbilical cord at birth, remnants of fetal
circulation are being visualized in MDCT
(multidetector computed tomography) images [12].



In progress
References
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References