Formerly at http://www.cordclamping.com/History.htm
This
is a documented history of accepted methods, and their rationale, of closing
the umbilical circulation after birth, when the newborn child converts from the
placental life support system to the independent life support systems of the
adult human. The natural
(physiological) process was clearly understood by obstetricians from 1773
through the 1970’s.
G.
M. Morley, MB ChB
1773 "The common method of
tying and cutting the navel string in the instant the child is born, is
likewise one of those errors in practice that has nothing to plead in its
favour but custom. 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?"
"A
Treatise on the Management of Pregnant and Lying-In Women" by Charles
White, published in 1773.
1801 “Another thing very
injurious to the child, is the tying and cutting of the navel string too soon;
which should always be left till the child has not only repeatedly breathed but
till all pulsation in the cord ceases.
As otherwise the child is much weaker than it ought to be, a portion of
the blood being left in the placenta, which ought to have been in the child.”
Erasmus Darwin, (Charles Darwin’s grandfather) Zoonomia, 1801;
Vol. III page 321
1842
Meigs: Regarding clamping a cord around the neck:
“The
head is born: perhaps the cord is turned once, or even more than once around
the child’s neck, which it encircles so closely as to strangulate it. Let the loop be loosened to enable it to be
cast off over the head. … [or] by slipping it down over the shoulders. … If
this seems impossible, it should be left alone; and in the great majority of
cases, it will not prevent the birth from taking place, after which the cord
may be cast off. … Should the child be detained by the tightness of the cord,
as does rarely happen, … the funis may be cut … Under such a necessity as this,
a due respect for one’s own reputation should induce him to explain, to the
bystanders, the reasons which rendered so considerable a departure from the
ordinary practice so indispensable. I
have known an accoucheur’s capability called harshly into question upon this
very point of practice. I have never
felt it necessary to do it but once. …
The cord should not be cut until the pulsations have ceased.”
Meigs C. Professor of
Obstetrics and Diseases of Women and Children, Jefferson Medical College. A Philadelphia Practice of Midwifery,
1842
1850 Churchill F (1850) On the Theory and Practice
of Midwifery. London: Henry Renshaw.
p 91
(#181 The umbilical cord, funis, or navel string) “After birth of the child,
the pulsation ceases in about fifteen or twenty minutes, and that portion of
the cord which remains attached to the umbilicus dies, and gradually withers,
until it falls off, in the majority of cases, on the fifth or sixth day.”
p
131 “…in ordinary cases, if we find that the cord is twisted around the neck,
all we need do is to draw down more of the cord, and either slip the lop over
the head or shoulders. If we cannot do
this, we must loosen the cord as much as we can, so as to prevent the
strangulation of its vessels, and wait for the uterus to expel the child.”
p 132 “If the child be healthy, and not have
suffered from pressure, &c. it will cry as soon as it is born, and when
respiration is established, it may be separated from its mother…”
1871 Cazeaux P (1871) A Theoretical and Practical
Treatise on Midwifery. Fifth American
from the Seventh French Edition by Wm R Bullock, MD. Philadelphia: Lindsay and Blakiston.
p. 406 “…the circulation existing between it [the
child] and the placenta is observed to continue for some time… pulsations in
the arteries gradually cease, commencing at their placental extremity; and some
authors have advised this event to be waited for before cutting the cord…”
1882 Lusk WT (1882) The
Science and Art of Midwifery. New York:
D Appleton and Company, pp214-215
"Infants
which have had the benefit of late ligation of the cord are red, vigorous, and
active, whereas those in which the cord is tied early are apt to be pale and
apathetic."
"1.
The cord should not be tied until the child has breathed vigorously a few
times. When there is no occasion for
haste, it is safer to wait until the pulsations of the cord have ceased
altogether.
2. Late ligation is not dangerous to the
child. The child receives into its
system only the amount of blood required to supply the needs created by the
opening up of the pulmonary circulation."
1910 Jellett, Henry (1910) 25.a.1910.1
A
Manual of Midwifery for Students and Practitioners. New York: William Wood & Company MDCCCCX
p.
350
"As
soon as the child is born, its eyes are wiped, any mucus in the air passages is
removed, and it is placed in a convenient position between the patient's
legs. The cord is tied as soon as it
has stopped pulsating, and the infant is then removed."
---------------------------
1917 Williams JW (1917)
Obstetrics: A Text-Book for the Use of Students and Practitioners, Fourth
Edition, pp342-343
"Immediately
after its birth the child usually makes an inspiratory movement and then begins
to cry. In such circumstances it should
be placed between the patient's legs in such a manner to have the cord lax, and
thus avoid traction upon it. "
"Normally
the cord should not be ligated until it has ceased to pulsate.."
"I
have always practiced late ligation of the cord and have seen no injurious
effects following it, and therefore recommend its employment, unless some
emergency arises which calls for earlier interference."
–
– – – – –
1921 von Reuss, August
Ritter (1921) WS 420 R446d 1921
The
Diseases of the Newborn. New YorkL
William Wood & Co, MCMXXI
(Vienna,
January 1914)
p. 419 – "… A compromise is usually adopted, in
that the cord is not tied immediately after birth, nor does one wait till the
expression of the placenta, but only until the cessation of pulsation in the
cord, an average of five to ten minutes."
1927 Willaims, J. Whitridge
(1927) 25.A.1927.2
Obstetrics:
A Textbook for the use of Students and Practitioners, Fifth enlarged and
revised edition. D. Appleton and Company, New York/London, 1927
Schücking.
Berliner Klin Wochenschr 1877 xiv, 5,18 "Zur Physiologie der
Nachgeburtsperiode."
Budin:
Obstetrique et Gynécologue, 1886, 1-35
Le Progrès Médical, 1875, decembre; 1876
janvier "À quel moment doite on opérer la ligature du cordon
ombilibale?"
P
359 –
"I
have always practiced late ligation of the cord and have seen no injurious
effects following it, and therefore recommend its employment, unless some
emergency arises which calls for earlier interference…"
1930 DeLee JB (1930) The Principles and Practice
of Obstetrics. Philadelphia and London:
WB Saunders Company.
“p. 330 “Tying the cord. – After waiting until the
pulsation in the exposed umbilical cord has perceptibly weakened or
disappeared, the child is severed from its mother. Until the cord is severed the child is still part of its mother
and has no legal existence… During the
four or eight minutes while waiting to tie the cord the child obtains from 40
to 60 gm. Of the reserve blood of the placenta – a fact that was first shown by
Budin. The blood is pressed into the
child by the uttering contractions, and part is aspirated by the expanding
chest. This extra blood the child needs
in its first days of life, and observation has shown that such children lose
less in weight and are less subject to disease…”
1933 Curtis AH, ed (1933)
Obstetrics
and Gynecology (3 vols). Philadelphia
& London: WB Saunders Company.
Baer
JL Chapt XXIV – The conduct of normal labor pp 702-844.
P
828 – "In most clinics the cord is not tied until pulsation has
ceased. This is based on the accepted
fact that the delay provides the infant with an additional average of 60 to 90
cc of blood. With premature infants or
twins, most of which are usually below the weights of average single infants,
this additional blood is a distinct advantage.
In full-term infants of normal size the advantage is more theoretical
than real."
1936 DeLee, Joseph B (1936) 25.A.1936.6
The
Principles and Practice of Obstetrics, Sixth Edition. Philadelphia and London: W.B. Saunders Company, 1956.
[earlier
editions: 1913, 15, 18, 24, 28, 33 (6th) à reprinted in 34 & 36]
p.
334 – "After waiting until the pulsation in the exposed umbilical cord has
perceptibly weakened or disappeared, the child is severed from its
mother."
"During
the four or eight minutes while waiting to tie the cord the child obtains from
40 to 60 gm of the reserve blood of the placenta – a fact that was first shown
by Budin. The blood is pressed into the
child by the uterine contractions, and part is aspirated by the expanding
chest. This extra blood the child needs
in its first days of life, and observation has shown that such children lose
less in weight and are less subject disease.
It is an error, on the other hand, to force the blood of the placenta
into the child by stripping the cord toward the child. This overloads its blood vessels, causes
icterus, melena, even apoplexy …"
1937 Fitzgibbon, Gibbon
(1937) 25.A.1937.2
Obstetrics.
Browne and Nolan Limited, Dublin/Belfast/Cork/Waterford, 1937.
p.
116 – Lateral position
p.
128 "…If the infant has cried and has respired well for about five
minutes, there is no advantage in leaving at attached any longer to the
placenta. Its pulmonary circulation has
been opened up and the pulmonary vessels filled with blood …"
1944 Read, Grantly Dick
(1944)
25.B.1944.2
Childbirth
Without Fear: The principles and practice of natural childbirth. Harper & Brothers Publishers, New York
and London, 1944.
P
95 – "It is my custom to lift up the crying child, even before the cord is
cut …"
"Its
first cry remains an indelible memory on the mind of a mother; it is the song
which carried her upon its wings to an ecstasy mere man seems quite unable to
comprehend."
1950
Eastman HJ (1950) Williams Obstetrics, Tenth Edition, pp 397-398
"Whenever
possible, clamping or ligating the umbilical cord should be deferred until its
pulsations wane or, at least, for one or two minutes."
"There
has been a tendency of late, for a number of reasons, to ignore this
precept. In the first place the
widespread use of analgesic drugs in 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."
1951 Greenhill JP
(1951) 25.A.1951.2)
Principles
and Practice of Obstetrics; originally by Joseph
B.
DeLee, M.D., Tenth Edition. W.B.
Saunders Company, Philadelphia and London, 1951.
p.251
"After waiting until the pulsation in the exposed umbilical cord has
ceased, the child is severed from its mother."
"DeMarsh,
Alt, Windle and Hillis showed that those infants whose cords were not clamped
until the placenta had separated from the uterus had on average 0.556 million
more erythrocytes per cubic millimeter and 2.6 gm more hemoglobin per 100cc
during the first week than those whose cords were clamped immediately. These authors maintained that early clamping
of the umbilical cord is equivalent to submitting the child to a hemorrhage at
birth. Wilson, Windle and Alt found
that infants whose umbilical cords were clamped immediately after birth had a
lower mean corpuscular hemoglobin at eight and ten months of age than those
whose cords were clamped after the placenta began to descend into the
vagina. It was suggested then that
early clamping of the cord may lead to an iron deficiency during the first year
of life."
"McCausland, Holmes and Schumann
advise stripping the cord and placental blood into the infant because it is
harmless if done gently and because term babies receive about 100cc of extra
blood in this way. These authors claim
that babies receiving this blood had higher erythrocyte counts, higher
hemoglobin values, higher initial weights and less initial weight losses."
1952 Greenhill, JP (1955) WQ 100 G812p 1955
Obstetrics
Eleventh Edition WB Saunders Company, Philadelphia and London.
[1913,
15, 18, 24, 28, 33, 38, 43, 47, 51]
1
2 3 4 5 6
7 8 9 10
p
280-282 - "Immediately after the
baby is delivered it should be held well below the level of the vulva for a few
minutes or placed in a warm container the level of which is considerably below
the mothers' buttocks (Fig 279). The
purpose of keeping the baby at this level is to permit the blood in the
placenta to get to the baby. Dieckmann
and associates maintain that this procedure will add from 50 to 75 percent of
the blood in the placenta and cord to the newborn child. If the placenta separates while waiting,
expressing it from the uterus and holding it elevated for two or three minutes
will accomplish the same purpose. The
cord is cut after about three minutes or after it collapses. If the baby is in a special container, it is
left in until after the cord is cut. As
soon as possible after delivery any mucus in the air passages must be removed
with a soft rubber bulb or a tracheal catheter.
Tying the Cord.
After waiting until the pulsation in the exposed cord has ceased, using
dull scissors, the child is severed from its mother. With a piece of linen bobbin, coarse silk, rubber band or any
sterile strong string, the cord is ligated close to the cutaneous margin of the
umbilicus , making sure that there is no umbilical hernia which might allow a
loop of intestine to be caught in the grasp of the ligature. It is important to leave as little as
possible of the cord to be cast off except when a baby has
erythroblastosis…"
"DeMarsh, Alt, Windle, and Hillis showed that
infants whose cords were not clamped until the placenta had separated from the
uterus had an average of 0.56 million more erythrocytes per cubic millimeter
and 2.6 gm. More hemoglobin per 100 ml. during the first week than those whose
cords were clamped immediately. These
authors maintained that early clamping of the cord is equivalent to submitting
the child to a hemorrhage at birth.
Wilson, Windle and Alt found that infants whose umbilical cords were
clamped immediately after birth had a lower mean corpuscular hemoglobin at 8
and 10 months of age than those whose cords were clamped after the placenta
began to descend into the vagina. Thus
early clamping of the cord may lead to an iron deficiency during the first year
of life.
McCausland,
Holmes and Schumann advise stripping the cord and placental blood into the
infant because it is harmless if done gently and because term babies receive
about 100 ml of extr blood in this way.
Babies receiving this blood have higher erythrocyte counts, higher
hemoglobin valuies, higher initial weights and less initial weight
losses."
Dieckmann,
WJ, Forman JB, and Philips GW: Effects
of Intravenous Injections of Ergonovine and Solution of Posterior Pituitary
Extract on the Postpartum Patient. Am.
J. Obst. & Gynec 60:655 (Sept) 1950.
p
281 – "After waiting until the pulsation in the exposed cord has ceased,
using dull scissors, the child is severed from its mother."
P
832 – "In attempting to account for the death of babies delivered by
cesarean section, Landau and associates concluded that blood loss to the child
incurred by immediate clamping of the cord amounted to 90 ml, a quantity of
definite significance, especially in preterm infants. Improvement was noted in the condition of babies when drainage of
blood from the placenta, after its removal, was facilitated by suspending it in
a towel above the child for six to ten minutes or until the cord vessels
collapsed."
Landau
DB et al. (1950) J. Pediat 36:421, April 1950.
1958 Willson JR, Beecham CF,
Forman I, Carrington ER (1958) WP 100 x02
1958
Obstetrics
and Gynecology. The CV Mosby Company,
St. Louis, 1958
P
337 –
"The
baby is held with its head downward for a few seconds while the cord is
stripped from the introitus toward the infant several times. This adds 75 or more ml of blood, which
would otherwise be discarded with the placenta, to the infant's vascular
system."
P
373 –
"The
blood in the fetal circulation is distributed between the vessels in the
infant's body and those in the placenta …"
"…At
the end of the second trimester about half the total blood is in the placenta,
but as the baby grows larger relatively more is contained in the infant
itself. The blood volume of the newly
born baby is only about 250 ml.
Consequently as much as possible must be preserved.
If
clamping and ligation of the cord are delayed for several minutes after the
baby is born, as much as 100 ml of blood will be transferred from the placenta
to the baby. The same result can be
obtained by stripping the cord from the vulva toward the infant repeatedly
until no more blood enters the vessels from the placental end."
1965 Greenhill JP (1965) WQ 100 G 812p 1965
Obstetrics:
Froim the original text of Joseph B. DeLee, MD. Thirteenth Edition. W.B.
Saunders Company, Philadelphia & London.
[1913,
15, 18, 24, 28, 33, 38, 43, 47, 51, 55, 60]
1
2 3 4 5 6
7 8 9 10 11
12
p
376 – "After pulsation in the exposed cord has ceased, using dull
scissors, the child is separated from its mother."
1966 Taylor, E. Stewart
(1966) WQ
100 B40 1966
Beck's
Obstetrical Practice, Eight Edition.
The Williams & Wilkins company, Baltimore, 1966.
p.
202 – "After delivering the child, the obstetrician suspends it by its
feet … During this time the fluid within the tracheobronchial tree may be
expelled by gravity. Most infants take
their first extrautering gasp at this time, and it is well to have the trachea
clear."
"If
the obstetrician waits until the cord stops pulsating, the child receives a
considerable amount of blood (up to 100 ml).
This procedure is harmless to the normal infant and may be
beneficial. However, the extra blood
volume from the placenta may be detrimental in some pathological conditions of
the infant. The most notable of these
are maternal-fetal blood group incompatibilities, anomalies of the infant
cardiovascular system, or severe fetal asphyxia."
"In
normal full-term deliveries, the cord is clamped with two hematostats as soon
as the cord stops pulsating."
1966 Fitzpatrick E, Eastman
NJ, Reeder SR (1966)
Maternity
Nursing, Eleventh Edition, JB Lippincott Company, Philadelphia, Toronto, 1966.
[1929,
33, 34, 37, 40, Zabriskie's Handbook of Obstetrics, 1st to 6th
editions by Louise Zabriskie]
[1943,
48, 52, 7th to 9th editions, Zabriskie's Obstetrics for
Nurses, Tenth Edition, 1960, by Elise Fitzpatrick & Nicholson J. Eastman]
p
268 –
"…The
infant usually cries immediately, and the lungs become expanded; about this
time the pulsations in the umbilical cord begin to diminish. The physician usually will defer clamping
the cord until this occurs, or for a minute or so if practicable, because of
the marked benefit of the additional blood to the infant."
P
288 (emergency delivery) –
"There is no hurry to cut the cord, so this
should be delayed until proper equipment is available. It is a good plan to clamp the cord after
pulsations cease (but not imperative at the moment) and to wait for the
physician to cut the cord after he arrives."
1969
James LS (1969)
Resuscitation of the newborn, in DE Reid and TC Barton, eds, Controversy in
Obstetrics and Gynecology.
Philadelphia, London, Toronto: WB Saunders Company, pp 220-221.
"In
infants delivered by cesarean section, hemoglobin, hematocrit value, and blood
pressure have frequently been found to be lower than in infants delivered per
vaginum … due to a loss of blood into the placenta, since the uterus is not
contracting."
"Asphyxiated
newborn monkeys resuscitated before the last gasp show little or no cerebral
damage. On the other hand prolongation
of asphyxia for as short a period as four minutes after the last gasp is
accompanied by widespread tissue damage and abnormal behavior in the surviving
animals. Thus for the newborn monkey
the 'safe' period of anoxia is short if functional integrity is to be
maintained."
–
– – – – –
1976 Beischer, Norman A
& MacKay Eric V. (1976) WQ 100 B 4230 1976
Obstetrics
and The Newborn: For midwives and medical students. W.B. Saunders: Sydney, Philadelphia, Toronto, London, 1976
P
261 - "The umbilical cord is
usually clamped some 30 seconds after delivery, after nasopharyngeal aspiration
has been carried out."
p.
259 – illustration 41.6
"J. The mother has been turned into the dorsal
position and the cord is checked for pulsations.
K. The cord is divided between clamps, or,
alternatively, when pulsations cease, the cord is clamped close to the baby's
umbilicus using the plastic device shown in figure 41.6 L."
P 395 – "The optimal time for clamping (or
tying) the cord is not known for certain.
Late clamping of the cord results in an additional volume of blood
reaching the infant. This is harmful in
premature and erythroblastotic infants.
In the asphyxiated infant, early clamping allows rapid transfer of the
child for resuscitation purposes. In
other patients, the cord is clamped when pulsations cease."
1983 Bodyazhina V (1983) WQ 100.3 B667u 1983
Textbook
of Obstetrics: Translated from the Russian by Alexander Rosinkin (revised from
the 1980 edition). Mir Publishers, Moscow
P
156 - "The umbilical cord should
be tied up after its vessels stop pulsating, which occurs in 2-3 min following
the delivery of the infant. In the
course of a few minutes that the umbilical cord pulsates, from 50 to 100 ml of
the blood is delivered into the vascular system of the foetus from the
placenta. As soon as the pulsation
discontinues, the cord should be cut off and tied up in asceptic
conditions."
1986 Beischer, Norman A
& MacKay Eric V (1986) WQ 100.3 B 4230 1986
Obstetrics
and the Newborn: An illustrated textbook, Second Edition. WB Saunders Company, Sydney, Philadelphia,
London, Toronto, Tokyo, Hong Kong, 1986.
p.
381 - The optimum time of clamping is
30-60 seconds after birth: This will
provide some 80 ml of extra blood to the baby.
Excess blood volume in the baby can be a disadvantage, producing polycythemia
and hyperviscosity, with such attendant problems as respiratory distress, heart
failure, jaundice, convulsions and apathy."
p.
546 – "The optimal time for clamping (or tying) the cord is not known for
certain. Late clamping of the cord
results in an additional volume of blood reaching the infant. This may result in hyperviscosity, jaundice
and cardiorespiratory, neurological and renal problems. The extr blood specifically aggravates
jaundice in premature infants and in those with erythroblastosis, so early
clamping of the cord is advised in such infants."
P
710 –
Q. What is the significance of continued
pulsation of the arteries in the umbilical cord at birth?
A. It means that respiration has not
commenced. The physiological stimulus
causing closure of umbilical arteries (and ductus arteriosus) is an increase in
oxygen saturation of the blood which occurs when the lungs expand with
air."
pp 734-5
"Routine
practices concerning the time for clamping the umbilical cord vary. If the child's condition is satisfactory
cord clamping and severing can be delayed until pulsation has stopped and the
infant is position at or below the level of the mother. The additional blood transfused from the
placenta can be as much as 100 ml. The
benefits of this are not fully evaluated but the additional volume may be
harmful in preterm infants. Early
clamping facilitates prompt resuscitation, if required, and transfer to the
mother's arms…"
Apgar score:
0
1
2
Heart
rate
absent less than 100 greater
than 100
Respiratory
effort absent slow,
irregular good, crying
Colour
blue
or pale pink body, blue pink
extremities
Muscle
tone
limp
flexion of extremities active
Response
to nasal catheter nil
grimace
cough
or sneeze
1987 (3rd ed) p 258 – Needs of the term
infant, by Ernest N. Kraybill
"… with present information it seems reasonable
to avoid the extremes of immediate and of very late clamping. The first 30 to 60 seconds after delivery
are well spent in suctioning the airway … The normal newborn invariably cries
during this interval …"
1988 Hibbard, Bryan M (1988) WQ 100.3 H624p 1988
Principles
of Obstetrics. Butterworths, London,
Boston, Durban, Singapore, Sydney, Toronto, Wellington.
P
470
"Apgar
scores are recorded at 1 minute and again at 5 minutes, timing the observations
accurately (see chapter 43, Table 43.1).
Also the time to first breath and time to the establishment of regular
respirations are recorded."
"Permanent
cord clamps or ligatures (Figure 26.27) or special bands are applied to the
umbilical cord as soon as possible after birth…"
pp
734-5
"Routine
practices concerning the time for clamping the umbilical cord vary. If the child's condition is satisfactory
cord clamping and severing can be delayed until pulsation has stopped and the
infant is positioned at or below the level of the mother. The additional blood transfused from the
placenta can be as much as 100 ml. The
benefits of this are not fully evaluated but the additional volume may be
harmful in preterm infants. Early
clamping facilitates prompt resuscitation, if required, and transfer to the
mother's arms…"
1994 McGregor Kelly, Joan WS 420 N441 1987, 1994
General
Care (chapt 22) in Avery GB, /fletcher MA, MacDonald MG, eds . Neonatology, Pathophysiology and Management
of the Newborn, Fourth Edition. J.B.
Lippincott Company, Philadelphia, 1994 (1987, 1981, 1975)
P.
301 cites Cunningham et al. (Williams Obstetrics, 18th ed.)
"…As
soon as possible after suctioning, the cord is clamped…"
"…
consequences of a significant shift [of blood volume] toward the infant include
polycythemia, circulatory volume overload, and hyperbilirubinemia, and these
generally outweigh any potential advantage of augmenting the infant's iron
reserve…"
1991
ACOG Committee opinion: Bulletin 138 – April 1994 (replaces #91, February 1991)
(re-affirmed February 2002)
Utility
of Umbilical Cord Blood Acid-Base Assessment
“TECHNIQUE
Immediately
after delivery of the neonate, a segment of umbilical cord should be doubly
clamped, divided, and placed on the delivery table pending assessment of the
five minute Apgar score.”
1981
“Immediate
cord clamping before the child has breathed should be avoided … in certain
unfavorable conditions the consequences may be fatal.”
Peltonen T. Placental
Transfusion, Advantage - Disadvantage. Eur J Pediatr. 1981;137:141-146
1982 Immediate cord clamping can result in hypotension,
hypovolemia and anemia …”
Linderkamp O. Placental transfusion: determinants
and effects. Clinics in Perinatology 1982;9:559-592
1993“[Delayed
clamping, as opposed to immediate clamping,] has clinical and economic
benefits.”
Kinmond S et al. Umbilical Cord Clamping and
Preterm Infants: a Randomized Trial. BMJ 1993; 306: 172-175
1998
“To avoid
injury in all deliveries, especially those of neonates at risk, the cord should
not be clamped until placental transfusion is complete.”
Morley
G.M. Cord Closure: Does Hasty Clamping Injure the Newborn? OBG MANAGEMENT 1998; July 29-36.
This list has been compiled mainly by Eileen Simon from the Harvard Medical School Library.