Transition from fetal to postnatal circulation |
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Home -------- Site Map Apgar Oxygen an urgent ongoing need >>Transition fetal to postnatal circulation Tradition Protocols Outcomes Concerns Question Authority References Links Notes Contact: Eileen Nicole Simon eileen4brainresearch@yahoo.com |
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Clamping the umbilical cord at birth is a human invention, and has long been the subject of controversy. It is no doubt instinctive for most obstetricians and midwives to wait for an infant's first breath before clamping the cord; until the 1980s this was explicitly stated in most textbooks of obstetrics and midwifery. Many texts also taught that the cord should not be cut until pulsations in it had ceased. |
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Pulsations in the cord are from the infant's heart, pumping blood to the placenta for oxygen and nutrients. Valves in the heart that direct blood flow to the placenta close after full inflation of the lungs, but this can take up to 20 minutes or more after birth. |
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In 1773, Dr. Charles White commented: |
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"Can it possibly be supposed that this important event, this great change which takes place in the lungs, the heart, and the liver, from the state of a foetus, kept alive by the umbilical cord, to that state when life cannot be carried on without respiration, whereby the lungs must be fully expanded with air, and the whole mass of blood instead of one fourth part be circulated through them, the ductus venosus, foramen ovale, ductus arteriosus, and the umbilical arteries and vein must all be closed, and the mode of circulation in the principal vessels entirely altered - Is it possible that this wonderful alteration in the human machine should be properly brought about in one instant of time, and at the will of a by-stander?" |
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Charles White (1728-1813) |
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White C (1773) A Treatise on the Management of Pregnant and Lying-In Women. Canton, MA: Science History Publications, 1987, p 45 Available from: http://www.shpusa.com/bkindex.html |
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Posted: February 27, 2006 (a work in progress) |
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