The umbilical cord answer has to do with a condition called "polycythemia".

[poly=many cyt=cells emia= blood] The "many cells in the blood" translation
is referring to what we measure with a blood test called a "hematocrit".

 A hematocrit is a number that tells us what percentage of the blood is
made up of red blood cells - those concave red disc-shaped cells that carry
oxygen to the tissues of the body.

Not enough red cells is called "anemia".  Too many red cells is
"polycythemia". In terms of actual numbers, the average hematocrit of a
term newborn is 60% at 2 hours of age, 57% at 6 hours old  and 52% at 12
-18 hours.  By the numbers - 65% is technically polycythemia and many docs
treat at 70% whether the baby is clinically symptomatic or not.

So if some is good - why isn't more even better?

1. Efficient Oxygen transport - the job of the red blood cell - decreases
above 60% and drops drastically after 70%

2.  Blood flow decreases as hematocrit increases

3. Viscosity increases as hematocrit increases leading to blood "sludging"

The combination of 1, 2 & 3 cause problems with "thrombosis" which is blood
clotting where it's not supposed to.

This happens primarily in "capilary beds" which are networks of tiny blood
vessels - these can cause serious problems with areas like the brain, the
kidneys or the adrenal glands.

This leads to tissue hypoxia and acidosis - which means the tissues don't
get enough oxygen and release chemicals into the blood. Definitely not
good.

How do umbilical cord procedures lead to polycythemia?
1. Delayed clamping of the cord causes a higher volume of blood to enter
the baby - the problem is greater, the smaller the baby.  [The plasma
(liquid) part of the blood can pass through the vessel walls but the red
cells stay in the vessels.]

2. "Stripping the cord" - that is squeezing the cord blood into the baby
has the same effect as 1.

3. holding the baby below the mom at delivery - same effect as 1 again.

4. note - if you've ever heard of "twin-twin transfusion" that's when one
twin gets too much blood -is polycythemic and the other becomes anemic - an
oversimplification but related in kind.

The "extra blood" is also tied to maternal - fetal transfusion in some
cases and an increased risk of jaundice from the breakdown of all the extra
cells as was mentioned in an earlier post.

Babies with polycythemia often look "ruddy" and dark pink in color.

Gail
Gail Hertz, MD, IBCLC
Pediatric Resident
author of the little green breastfeeding book - disclaimer: owner of Pocket
Publications