Your baby's life support
The development of the fetus inside the utero from
a tiny group of cells to a fully grown baby occurs
with the help of the placenta, umbilical cord and
the amniotic fluid. This trio forms your baby's life
support system before she makes her entry into the
• 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
• 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
• 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
Amniotic Fluid - the useful
• 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
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.
• The cord starts to form by the 26th day of
embryonic life; it is usually about 50 cm long, 1-2
cm in width with 2 arteries and 1 vein.
• It coils into a spiral. The cord is a moist
dull white, semitransparent, jelly like rope that
runs from the navel of the fetus to the fetal surface
of the placenta. It is considered the lifeline of
the fetus as it connects the fetus to the nutrient-rich
• Some cords are straight, some twisted and
others become knotty because of fetal movements.
• Inside the cord is a jelly like substance
called the 'Wharton's Jelly' which cushions the blood
vessels. Occasionally the cord forms a knot, known
as false knot but this seldom poses a problem as it
doesn't hinder the blood flow.
• Fetal blood which is low in oxygen and high
in waste products travels through the two arteries
into the placenta. Blood gets purified; oxygen and
nutrients are absorbed from the maternal blood and
returns to the fetus through the single umbilical