Chronology of a New Life
The life of a
baby begins, of course, long before birth. Every new and unique human
being begins his or her life at the moment of fertilization and, if not
interrupted, will someday grow into an adult man or woman. Following are
some facts of our earliest days of life, recognized in medical texts as
well as basic biology books.
joins the ovum (egg) to form one cell. This one cell contains the complex
genetic blueprint for every detail of human development - sex, hair and
eye color, height, skin tone, etc. Over the next week the tiny fertilized
egg (or blastocyst) travels down the fallopian tube into the uterus,
implanting in the nutrient-rich lining which has been prepared by the
hormone progesterone. The embryo begins developing very rapidly, and by 22
days the heart begins to beat. By the end of the third week the backbone,
spinal column and nervous system are developing. Kidneys, the liver and
the digestive tract are already taking shape. By the end of the first
month the embryo is ten thousand times larger than at the blastocyst
stage. This tiny baby has grown to about 1/4 of an inch in length.
At this stage
of development the head of the embryo is almost one half of his or her
total size. Brain tissues grow rapidly, dividing and becoming a miniature
brain that is distinctly human. By 40 days (the sixth week) brain waves
can be recorded. Fingers and feet are beginning to develop. Milk teeth
form at 61/2 weeks. Facial features, including ears, nose, lips and
tongue, form with clarity during this month. Eyes form and darken when
pigment is produced around day 35. Eyelids cover the eyes and will soon
form a protective seal, reopening during the seventh month. Near the end
of the month the skeleton changes from cartilage to bone. Forty muscle
sets begin their first exercises and, working with the nervous system,
respond with small movements to touch. The baby's blood type is often
different from his or her mother's. By eight weeks all body systems are
present, and from now on changes will be primarily in size and refinement
of body parts already formed. The tiny baby at this stage is called a
fetus, Latin for "offspring" or "young one."
month the baby grows to a length of more than two inches and a weight of
one ounce. At nine weeks fingerprints are evident and never change. The
baby now sleeps, awakens and exercises muscles energetically - turning the
head, curling toes and opening and closing his or her mouth. The palm,
when stroked, will make a tight fist. Fingernails and toenails form, and
the baby's sex is now identifiable. The baby breathes amniotic fluid to
help develop and strengthen the respiratory system. Vocal cords are
complete, and at times it appears as if this little baby is crying.
during this month - the baby grows to eight to ten inches in length and
weighs a half pound or more - means the mother often begins to show and
may feel her baby move. Bone marrow is forming, and the heart can be
plainly heard as it pumps up to 25 quarts of blood each day. Nutrients in
food consumed by the mother are passed on to her baby within an hour or
two via placenta and umbilical cord - which is transporting three hundred
quarts of fluid per day! Facial expressions similar to the baby's parents
can be identified at this time. Fine hair begins growing on the head,
eyebrows and eyelashes. The baby learns to grip and suck his or her thumb.
pregnancy has now passed and this little baby is very active! Sleeping
habits develop and the mother often feels her baby move and stretch,
particularly when she is resting. Interestingly, babies at this stage have
responded to sounds in frequencies too high and low for adults to hear. By
the end of this month the baby is about 12 inches long and weighs about
one pound. Babies born at this stage of development have survived.
The baby, now
up to 14 inches long and a pound and a half in weight, can now roll over
inside the womb. Oil and sweat glands are functioning and the baby is
covered by a white filmy layer called vernis (Latin for
"varnish") which protects the delicate skin from the surrounding
amniotic fluid. At the end of this month the baby has completed two-thirds
of his or her stay in the womb and because the lungs are fairly
well-developed would stand a good chance of survival if born at this time.
weighs at least two pounds by the seventh month. All four senses are now
used, the eyelids open and close, and eyes look around. The baby can
taste, touch and recognize his or her mother's voice. Eye teeth are
present within the baby's gums, and this little baby's hands develop an
even stronger grip. During the last trimester the baby receives antibodies
from the mother through the placenta that will provide immunity to a wide
variety of diseases.
begins to thicken with a layer of fat stored beneath for insulation and
nourishment. Antibodies to give immunity against disease are continuing to
be received from the mother, strengthening and preparing this baby for
life outside the womb. The baby absorbs a gallon of amniotic fluid per
day; the fluid is completely replaced every three hours. During this month
the baby gains at least two pounds, doubling his or her weight, and the
mother is probably looking forward to the delivery date!
By the ninth
month, weighing six to nine pounds, this baby can only turn from side to
side because of very cramped quarters. At this point most babies settle
into a head-down position to prepare themselves for delivery. About a week
before birth, growth stops and changes in the mother's hormonal balance
signal the onset of labor and birth. Over the past nine months, one cell
has become two hundred million cells, weighing six billion times more than
at fertilization, yet containing - in a bit greater detail - the same
unique person that came into being at that first moment!
provided in this chronology are taken from The
First Nine Months of Life by Geraldine L. Flanagan and When You Were Formed in Secret by Gary Bergel.