All new midwives in the US are not taught to cut and clamp a nuchal cord!
The preferred method is to 1) reduce the cord over the baby's head if it will
go easily or 2) reduce the cord back over the shoulders as the baby is born
and deliver the body thru the cord, or 3) if it is tight, a somersault
maneuver can be used as described in an article by Schorn (Schorn MN, Blanco
JD. Management of the nuchal cord. J Nurse Midwifery 1991;36:131.).
In 1998, we completed a questionnaire of American nurse-midwives and cord
clamping practices. (Mercer, J., Nelson, C., Skovgaard R (2000). "Practices
and Beliefs about Umbilical Cord Clamping of American Nurse-Midwives" Journal
of Midwifery and Women's Health, 45(1), 58.) Some notes -- "When questioned
about management of nuchal cord, fifty-seven percent of the respondents chose
the option "Clamp and cut only when very tight." The somersault maneuver
(Schorn, 1991) was selected by 40% of the participants as their best option
for managing nuchal cord and only 3.2% stated that they clamp and cut in most
cases of nuchal cord.
When confronted with a nuchal cord, 96% of the CNMs avoid immediate clamping
and cutting of the cord. This practice is well supported in the literature.
The umbilical vein walls lack the muscular layer found in arteries and is
more easily compressed. Blood is pumped by the driver of the system, the
fetal heart, to the placenta from the fetus via the arteries, but compression
of the vein prevents the oxygenated blood from returning to the fetus. Thus
a nuchal cord may result in a fetus to placenta transfusion. With immediate
clamping, a neonate having a nuchal cord is at risk of hypovolemia and anemia
(Cashore WJ, Usher R. Hypovolemia resulting from a tight nuchal cord at
birth (Abstract). Pediatr Res 1973;7:399).
Another issue related to the management of a nuchal cord is the risk of
shoulder dystocia following the cutting and clamping of a nuchal cord. Iffy
(Iffy L, Varadi V. Cerebral palsy following cutting of the nuchal cord
before delivery. Medicine & Law 1994, 13:323-30) reported 5 cases of cerebral
palsy after nuchal cords were cut and shoulder dystocia delayed the birth by
as little as three minutes. These facts make it highly advisable to avoid
cutting the nuchal cord before delivery whenever possible. Schorn describes
the somersault maneuver which keeps the neonate's head close to the perineum
to decrease tension and allow the cord to be unwrapped after birth. It is
preferable to allow these babies to reperfuse and to be resuscitated if
needed at the perineum. Those at risk of hypovolemia present with white,
"drained" bodies (or mottled blue and white), no tone, and no reflexes.
However, they usually have heart rates above 100 and will reperfuse,
correcting any acid-base imbalance that exists as evidenced by the return of
tone about the same time that the baby begins breathing (Mercer, cases in
progress). If the heart rate is not above 100, resuscitation can be done at
the perineum without clamping the umbilical cord of the obviously hypovolemic
infant. The infant can be dried and put on clean pads at the perineum or
skin to skin on the mother's abdomen to keep warm. Theoretically, the only
time that this process would not work is if the placenta separates
immediately.
Two other articles that shed light on this whole issue are: 1) Mercer, J.
Skovgaard R. "Neonatal transitional physiology: A new paradigm." Journal
of Neonatal and Perinatal Nursing, 2002;15(4):56-75.
2) Mercer, J. (2001). "Best evidence: A review of the literature on
umbilical cord clamping." Journal of Midwifery and Women's Health, invited,
November/December 2001;46(6):402-414. This article was reprinted in MIDIRS
in Summer of 2002.
This is my area of research and would be happy to share more info with
interested parties. Have just been funded by NIH (starting 3/1/03) to begin
a research project on this issue and will have more time to participate in
this sharing once I get started!
Judith Mercer, CNM
Director, University of Rhode Island Nurse-Midwifery Program.
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