Very early clamping results in less than physiologic blood volume. The normal, term child routinely survives, but clamping the cord of a compromised child before ventilation is riskier. Initial aeration of the lungs causes reflex dilatation of pulmonary arterioles and a massive increase in pulmonary blood flow. Placental transfusion normally supplies this volume. Clamping the cord before the infant's first breath results in blood being sacrificed from other organs to establish pulmonary perfusion. Fatality may result if the child is already hypovolemic.
Because placental transfusion patterns vary widely, it is futile to attempt to give the newborn the "right" amount of blood by clamping at a set time after birth. However, it is extremely likely that the infant will have less-than-optimal blood volume if the cord is clamped before the lungs are ventilated.
In clinical practice, late clamping produces a high hematocrit, high blood pressure, and vasodilatation to accommodate the large volume of blood. These latter two factors should increase tissue perfusion. In searching the literature, I was unable to find any documented case of hyperviscosity syndrome in which the cord was clamped late, although I did find many documented cases of late clamping involving normal newborns with high hematocrits.
There are, however, many documented cases of hyperviscosity syndrome with high hematocrits (e.g., cases involving gestational diabetes or postmaturity) in which the cord was clamped before physiologic cord closure, thus creating low blood volume, low blood pressure, and vasoconstriction coupled with the polycythemia. The inadequate tissue perfusion is blamed on the high hematocrit, when the root cause of the hyperviscosity syndrome is hypovolemic vasoconstriction enforced to the fourth power.
-excerpted from George M. Morley, MB., CH. B, Cord Closure: Can Hasty Clamping Injure the Newborn? July 1998 OBG Management. Submitted by Kathryn Weymouth
Following are some thoughts and ideas Gloria Lemay, private birth attendant in British Columbia, has gleaned over the years about leaving the umbilical cord to pulse until it stops:
l. Leaving the cord to pulse does no harm and therefore should be encouraged. Think about what nature intended: our ancestors way back before scissors and clamps were invented must have had to wait to deal with the cord/placenta until the placenta was birthed. They probably chewed it, ground it with rocks, or burned it through with hot sticks from the fire. The little teeth on the clamps indicate that traumatizing of the vessels is necessary to quell bleeding.
2. Leaving the cord to pulse slows down the "fire drill" energy that many birth attendants get into after the baby is born. Leaving off the busyness of midwifery for a half hour allows the mother and baby undisturbed bonding time without a "project" going on. The father, too, is undisturbed and able to enjoy this time without focusing on a job at hand.
3. Educator Joseph Chilton Pierce in his book "Magical Child" makes reference to studies that were done on primates who gave birth in captivity and had early cord clamping. Autopsies of the primates showed that early cord clamping produced unusual lesions in the brains of the animals. These same lesions were also found in the brains of human infants when autopsied.
4. In Rh negative women, many believe it is the clamping of a pulsing cord that causes the blood of the baby to transfuse into the bloodstream of the mother, causing sensitization problems.
5. It is interesting that scientists are now discovering that umbilical cord blood is full of valuable T-cells that have cancer fighting properties. A whole industry has sprung up to have this precious blood extracted from the placenta, put in a cooler with dry ice, and taken to a special storage facility to be ready in case the child gets cancer at some time in the future. This is human insanity of the first order. That blood is designed by nature to go into that child's body at birth, not 30 years later!
6. The only time I cut a cord before the placenta comes out is if I have a mother in a water tub and I'm worried about blood loss. Then you have to get both out onto a dry surface quickly and it's easier to hand baby over to an adult while mom is lifted separately. This situation has never happened until after the cord has stopped pulsing.
7. If the baby needs resuscitation, it is important to leave the cord and do all work to help the baby while he/she is on mom's body. Cutting the backup oxygen supply doesn't make any sense at all.
I have read a lot on the issues surrounding immediate and delayed cord clamping and cutting and the more I read, the more I understand the absolute benefits of doing nothing. I am not a midwife, but a doula who just happens to have witnessed the births of hundreds of calves. We allow the cord to break naturally without clamping and very rarely is a calf ever compromised by infection, even in a pasture that is far less than sanitary.
I was intrigued by a debate on an OB/Gyn list about the benefits of immediate cord clamping or delaying this procedure in babies with low Apgars, and how beneficial giving the mother Narcan is and its almost immediate beneficial effect on the newborn--as well as for meconium and other compromising situations in which babies greatly benefit from the bonus oxygen they receive through the umbilical cord. Kind of makes you think, when meconium protocol dictates immediate clamping and cutting while baby is whisked off to be suctioned aggressively in hospitals!
And finally, something unheard of in hospital births: not clamping or tying the cord at all and severing it only when it has completely stopped pulsating decreases the incidence of umbilical hernia (which I have seen in hospital clients' babies even with delayed clamping).
Mother Care Doula Services, Childbirth Education, Doula/CBE Catalogue Camrose, Alberta, Canada
Reprinted from Midwifery Today E-News (Vol 1 Issue 30, July 23, 1999)
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