Cunningham FG, Hauth JC, Leveno KJ, Gilstrap L III, Bloom SL, Wenstrom KD, eds,
Williams Obstetrics - Twenty-second edition, New York: McGraw-Hill Medical
Publishing Division, 2005
http://www.statref.com/
Online version at
"Clamping the Cord. The umbilical
cord is cut between two clamps
placed 4 to 5 cm from the fetal
abdomen, and later an umbilical cord
clamp is applied 2 to 3 cm from the
fetal abdomen. A plastic clamp
(Double Grip Umbilical Clamp,
Hollister) that is safe, efficient, and
fairly inexpensive is used at Parkland
Hospital.
TIMING OF CORD CLAMPING. If after
delivery, the newborn is placed at or
below the level of the vaginal introitus
for 3 minutes and the fetoplacental
circulation is not immediately occluded
by clamping the cord, an average of
80 mL of blood may be shifted from
the placenta to the neonate (Yao and
Lind, 1974). This provides about 50
mg of iron, which reduces the
frequency of iron deficiency anemia
later in infancy.
Accelerated destruction of erythrocytes, as found with maternal alloimmunization,
forms additional bilirubin from the addederythrocytes and contributes further to the
danger of hyperbilirubinemia (see Chap. 29, p. 667). Although the theoretical risk
of circulatory overloading from gross hypervolemia is formidable, especially in
preterm and growth-retarded neonates, the addition of placental blood to the
otherwise normal newborn's circulation ordinarily does not cause difficulty.
Our policy is to clamp the cord after first thoroughly clearing the airway, all of
which usually requires about 30 seconds. The newborn is not elevated above the
introitus at vaginal delivery or much above the maternal abdominal wall at the time
of cesarean delivery."
From chapter 17, section IV
Yao AC, Lind J: Placental transfusion. Am J Dis Child 127:128, 1974
From the bibliography for
http://placentalrespiration.net/
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