Courtesy Readers Digest 1981. November.
From the frontiers of science and the far horizons of
personal courage, these stories of medical triumphs and miracles will reaffirm
your faith in the awesome powers of the human spirit. Dramatic victories and human
triumphs
From conception to birth, the growth of a baby proceeds with
astonishing speed. In the first month
alone the tiny organism increases to nearly ten thousand times its initial
weight. In the first three months it
progresses from a speck of watery material to an infinitely complicated human
form—unfinished, to be sure, but recognizably a baby-to-be. The whole process is a marvel of refinement
that staggers the imagination. One
change prepares the way for the next, and the plan, for all its subtlety, is
marked by incredible accuracy. This
transformation, taking about 267 days, is the unbelievable manner in which
one’s own, and everybody’s, biography begins.
At conception the male sperm joints the female egg, and
immediately the 48 chromosomes in the nucleus of this completed cell begin to
churn about, a prelude to the first cell division. The fertilized egg is approximately as big as
the dot over this “i”. Yet physically
present within it are all the genetic characteristics that will make this the
particular child of a particular family—John Smith, Jr. let’s say, with his
father’s blue eyes and his maternal grandmother’s aptitude for music.
As cell divides [splitting into two, the two becoming four,
and so on] the egg floats down through one of the two Fallopian tubes to the
womb, a two=inch journey that takes three to four days. By the time it reaches the womb the egg is
usually about its 16-cell stage. Even at
this early date a mysterious development has taken place. There are now two markedly different kinds of
cells: flat, fast dividing cells that form the delicate outer layer, and
slow-dividing inner cells which are plump and roundish.
From the fourth to the sixth or seventh day the egg-ball,
now about the size of a pinhead, floats in the warm, dark, fluid filled womb
cavity. The velvety lining of the womb,
interlaced with small blood vassals, has become extraordinarily soft and thick,
as it does once every 28 days during the mother’s childbearing years. On about the seventh day, as the egg drifts
against this lining, it begins to burrow vigorously into the spongy material
and completely embeds itself, opening up some of the hair like capillaries in
the process and releasing the blood inside them. Now, all over its surface, the egg-ball
sprouts tiny, fast-growing projections called “villi”—many hundreds of them. Lied minute plant roots, they dip into the
infinitesimal pools of blood and absorb oxygen and food-minerals,
carbohydrates, proteins, fats. With
food, the egg-ball frowns quickly.
All these events have taken place before the mother knows
she is pregnant; chances are she will not find out about it before 21st day at
the earliest.
Inside the sphere, meanwhile, the colony of round cells has
formed itself into two tiny sacs, the yolk sac and the amnion. Where the sacs touch, they interact and
produce a third layer of cells—making a three-layered disk. The rest of the yolk sac will not be
important in future, though the amnion remains a key structure until
delivery. But the three-layer cellular
disk now has the star part, for it is about to transform itself into the
embryo.
Each layer will provide the baby-to-be with material for
specific kinds of tissues. One is the
source for the cells that will form its nervous system, skin, hair,
fingernails, tooth enamel and the linings of its nose and throat. The middle layer will supply cells for the
baby’s muscles, bones and cartilage, blood vessels, kidneys ad tooth
dentine. The third layer will provide
the digestive tract and most of the respiratory system.
The next transformation is, perhaps, the most miraculous of
all. About the 19th or 20th day the disk
develops a groove like crease down one of its surfaces, with ridges on either
side. The ridges converge at one
end—that is to be the head. As the
ridges rise and fold towards each other, the disk becomes partly tubular and
crescent-shaped. The outside curve will
become the baby’s back. In a few days
the first suggestion of the spinal column will appear, and the brain matter
will start to fill the hollow at the head end.
Small buds, the first hind of arms and legs, are due shortly. By the 21st day a rudimentary heart has
formed. Ten days later it has started to
beat.
The embryo is connected with the casings of the sphere by a
thread of cells, which will in time lengthen into a dull white 22-inch rope-the
umbilical chord. Enclosed within the
amniotic sac as well, the embryo is doubly wrapped—a minute crescent inside a
tissue bag inside a tissue ball buried in the spongy womb lining. Moreover, the sac is filled with a clear
watery liquid which is an effective shock absorber—pregnant women have been in
hair-raising accidents without losing their babies.
From now on the embryo quickly takes on a babyish
appearance. By the end of the second
month it is only one inch long from head of rump, but it has a nose, mouth,
ears and a suggestion of what will become eye sockets.
By the end of the third month the embryo—from now on called
a “fetus”—is three inches long and about one ounce in weight. Its various body systems show faintly what
they are soon to become. Eyes and
eyelids are formed, though, for the time being, they are closed. Sexual organs are present. Arms and legs are complete down to finger and
toenails, and the fetus has started to move them, although this first movement
is imperceptible to the mother.
Its heart has been beating for two months, gaining muscular
strength. The fetus has also begun to
swallow small amounts of the amniotic fluid, an exercise not only in swallowing
but also in something like breathing. The
liquid enters its lungs, and then the fetus expels it, using the breathing
muscles. It is now just practice; until
birth the fetus gets all its oxygen and food from the mother’s blood.
All these astonishing developments have taken place in just
the first three months. The mother’s
womb has enlarged nut, except perhaps to he own eyes, the swelling of her
abdomen is still negligible. For the
next six months, while the fetus grows to baby size, its ability to function as
a newborn will develop gradually.
The umbilical chord is the only connection between the
mother and fetus. The chord contains no
nerves, and since the nervous system of mother and fetus are entirely separate,
nothing the mother thinks or perceives can affect her offspring. This is why the age-old supersistitions about
prenatal influence are false.
As with its nervous system, the fetus’ circulatory system is
entirely independent. The fetus
manufactures all its own blood, which never mixes with that of its mother. The two blood streams simply exchange
materials inside a remarkable organ called the placenta, which develops in the
womb during pregnancy and is expelled at the end of the birth process. The placenta, which is connected to the fetus
by umbilical cord, is shaped like a flat cake five or six inches in diameter. Most of this bulk is made up of villi, equipped
now with blood vessels and intermeshed with digests on the fetus’ behalf an
incalculably valuable service, for it allows the future baby’s respiratory and
digestive systems to remain latent while they grow.
Toward the latter part of the fourth month the mother feels
the fetus moving. This ‘quickening” is
at first very faint; weeks my elapse before the flexing of the fetus’ arms and
legs become unmistakably strong. Now,
halfway through the pregnancy, the fetus is six inches long and weighs six
ounces. Eyebrows and eyelashes have
appeared. For the first time the
heartbeat is strong enough to be heard with a stethoscope. It beats about 136 times a minute, almost
twice as fast as the mother’s heart. One
additional milestone; a discernible amount of calcium has now been deposited in
the fetus’ soft, gristle like bones.
By the end of the sixth month the fetus is a foot long,
weighs about a pound and a half. It can
hiccup, move its facial muscles and sneeze.
Its eyes are almost fully developed, but at best are sensitive only to
light. If fetus were born now, it might
survive, but the chance is exceedingly remote.
Gaining dramatically in strength, the fetus now stretches
and squirms, moving not only its arms and legs but also its body and head. Its chest muscles, in preparation for
breathing air, grow stronger every day.
Its kidneys are working and its intestines are active despite the fact
that normally there will be no evacuation until after the delivery. Rehearsing the reflex action that after birth
will provide food, and fetus is making sucking motions more of less
constantly. In fact, it may vary well be
sucking its thumb, as some babies do before they are born.
Toward the end of the end of the ninth month, of on about
the 252nd day, the fetus is “mature,” ready to born. The 267-day figures are only a statistical
average; 15-day variations either way are commonplace.
The mature fetus usually weighs something between six and
seven pounds; it is close to 19 inches tall.
Its arms are folded across its chest and its thighs drawn up against the
stomach, a position that takes up the least possible space. Most of the time it is quiet [and presumably
in a state very much like sleep], but now when it thrusts its arms or legs the
movements are really powerful. If the
doctor places the palm of his hand over the womb, the fetus is likely to answer
with blows of protest.
This is a small but complete human being. Any day now he will face his first great
ordeal, the process of being born.
Everything for him is in a sense still to come. And yet no one would deny that his experience
already has been a truly marvelous one.
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