The Placenta
• The placenta is a temporary, disc-shaped
but an essential organ through which the
fetus absorbs food and eliminates waste.
It is connected to the uterine wall on one
end and attached to the baby via an umbilical
cord.
• There is an on-going delicate interchange
between the mother and the fetus. Materials
travel from the maternal system to the other
and vice versa. For example excess blood
sugar from the mother's blood passes into
the fetal blood until equality is achieved.
That is the sugar the mother eats is passed
to her baby. Oppositely excess carbon dioxide
from the fetal blood crosses over into the
mother's blood and is exhaled by her lungs.
The mother essentially breathes for her
child. Likewise all waste products are absorbed
and eliminated through the mother's kidneys.
• The placenta protects the fetus
by blocking the passage of many potentially
harmful substances e.g. drugs and chemicals
• The placenta is essentially a network
of arteries and veins fully functioning
between weeks 10 and 12; it collects oxygen
and nutrients from the maternal bloodstream,
processes them and passes them on to the
baby. It also filters and transports waste
materials from the fetus (carbon dioxide,
baby's waste) to the mother's system for
disposal. However maternal blood and baby's
blood can come very close to each other
but do not mix.
• The placenta is also responsible
for the manufacture of a number of hormones
viz HcG, HPL, Oestriol and Progesterone
• The placenta develops from the chorionic
villi during the second month of pregnancy.
The chorion is the outer surface of the
sac holding the embryo. On one side the
villi will burrow into the uterine wall
to receive nourishment from the mother and
the villi on the opposite end will flatten
out.
• The placenta will grow in size and
reach its full thickness of about 2.5 cm
by the 4th month. At birth it will weigh
about 500 gm and measure at 20 cm in diameter,
about one sixth the size of the baby.
| |
|
 Are
You a US Mom who is Pregnant
and Without Maternity Insurance?
"Whether
you're 1 or 40 weeks pregnant, Maternity Advantage can help
with medical expenses, cribs, baby clothes, bedding, baby
food and diapers.
Click
here for free information on
how you can save up to 65%."
|
|
|
| |
Amniotic
Fluid - the useful fluid
• The fluid is essentially water at
first; it is colorless and surrounds the
fetus. As pregnancy advances, the fluid
will start to turn straw-colored as it now
contains skin cells shed by the fetus, fetal
hair, vernix, various minerals, salt, sugar
as well as fetal urine.
• Until 14 weeks amniotic fluid is
absorbed by the baby's skin. As her kidneys
start to function and her sucking reflex
develops she will start to swallow the fluid
and excrete it back into the sac as urine.
Most of the fluid contained in the sac is
now fetal urine.
• Amniotic fluid serves many functions.
It allows the fetus to move unhampered hence
aiding in the development of muscles and
bones. It is particularly useful for fetal
lung development
• It acts as a good insulator against
cold and heat and provides the fetus protection
against temperature changes. It is also
and excellent shock absorber
• The fluid can also provide valuable
information about fetal well being and growth.
• Pregnancy doesn't lessen the chances
for injury but the fetus in most instances
is cushioned by the amniotic fluid against
blows and falls. An accident rarely triggers
premature labor or membrane rupture. It
only becomes a situation for concern if
the injury involves the use of weapons or
sharp penetrative objects.
• 95% of the fluid is replenished
every day. During the later half of pregnancy
fluid is lost because it is swallowed by
the fetus. Most of it is returned as urine.
About one pint is swallowed and a similar
quantity is urinated on a daily basis. Baby
swallows amniotic fluid as she practices
breathing and then urinates it out. The
fluid is constantly being recirculated.
• At 16 weeks the fluid measures at
about 200 ml and at term the volume grows
to about 1000 ml.
|
