Gestation is "the act of carrying young in the Uterus, from the time of
conception to that of parturition." Conception occurs at the moment of
the impregnation of the ovum; parturition is the act of delivery, or
childbirth. Pregnancy is "the state of being with child." The terms
"period of gestation," and "period of pregnancy," respectively, are
employed by medical authorities to designate the time during which the
mother carries the young within her own body--from the moment of the
impregnation of the ovum until the moment of the final delivery of the
child into the outer world.
The term of pregnancy in woman continues for over nine calendar months
(or ten lunar months)--from about 275 to 280 days, though in exceptional
cases it may be terminated in seven calendar months, or on the other
hand may continue for ten calendar months. The usual method is to figure
280 days from the FIRST DAY of the LAST MENSTRUATION. A simple method of
calculating the probable date of delivery is as follows: COUNT BACK
THREE MONTHS, AND THEN ADD SEVEN DAYS, AND YOU WILL HAVE THE DATE OF
PROBABLE DELIVERY. Example: A woman's FIRST DAY OF LAST MENSTRUATION is
March 28. Counting back three months gives us December 28; and adding
seven days to this gives us January 4, as the date of probable delivery.
There will always be a possible margin of a few days before or after the
ascertained probable date--but the delivery will very closely
approximate said date. Ignore the shortage of days of February in this
calculation, the same being covered by the general margin allowed.
DEVELOPMENT OF THE IMPREGNATED OVUM. In the preceding lesson we
terminated our consideration of the impregnated ovum at the point at
which, after the process of segmentation, the "primitive trace" had
appeared. This primitive trace appears as an opaque streak, or straight
line, formed of an aggregation of cells of a distinctive quality. This
delicate "trace" or "streak" is the first indication of the form of the
coming child. It is the basis, pattern, or mould, in or around which the
spinal column is to be formed, and around which the entire young body is
to be developed by the wonderful and intricate processes of dividing and
reduplication, and the folding and combination of cells. From one end of
this "trace" develops the head; from the other end develops the lower
end of the spine. At a later stage there appear tiny "buds" in the
positions at which the arms and legs should be; these gradually develop,
and their ends split into tiny fingers and toes, and finally are
transformed into perfect little arms and legs, miniatures of those of
the adult human being.
The term "the embryo" is employed to designate the developing young
creature in the earlier stages of its development, particularly before
the end of the third month of its existence. After the end of the third
month the embryo is called "the fetus." In the short space of 280 days
the young creature evolves and develops from a single simple cell into a
complex organism--a perfect miniature human being. Nature works a
wonderful miracle here, and yet so common is it that we take it all as a
matter of course, and lose sight of the miracle. From the most simple
forms are formed in the developing creature the most complex organs and
parts. The heart is formed from a tiny straight line of cells, by
enlargement and partition. The stomach and intestines, likewise, develop
from a tiny straight line of cells arranged as a tiny tube--the stomach
is formed by dilation of one part of the tube, while the large
intestine experiences a similar though lesser distention and a greater
growth in length; the smaller intestines being formed by growth in
length and circumference. The other organs evolve from similar simple
beginnings.
The embryo is nourished during its earlier stages by means of the "yolk
sack," or "umbilical vesicle," which is outside the body of the embryo,
being joined to it by means of the umbilical duct. This yolk sack
(originally formed by a "drawing together" in the ovum, which thus
separates itself into two portions or areas) is an important feature of
the life of the embryo, as it nourishes and sustains it in its earlier
stages. Blood vessels form in this yolk sack, and after a time its fluid
is absorbed, and after the third month the sack gradually disappears.
After the passing away of the yolk sack, the embryo is nourished and
sustained by the "allantois," another peculiar sack which is formed.
This sack readily becomes filled with blood-vessels, and serves to
nourish the embryo by sustenance obtained from the body of the mother
through the walls of the Uterus, a direct communication with the
blood-vessels of the mother thus being secured. The blood in the embryo,
and that in the mother, come into close contact, thus allowing the
embryo to be nourished by the blood of the mother. After a time, in
turn, the allantois diminishes and dwindles away, its offices being
taken up and performed by the "placenta" or "afterbirth."
THE PLACENTA OR AFTERBIRTH. The Placenta, or afterbirth, is a round,
flat substance or organ, contained within the Uterus, by which
communication and connection is established and maintained between the
fetus and the mother, by means of the umbillical cord. It is a flat,
circular mass, about seven inches in diameter, and weighing about
sixteen ounces. It is attached to the sides of the Uterus of the mother
during the period of gestation, and is expelled from the body of the
mother, as "the afterbirth," after the birth of the child.
Let us pause a moment, and reconsider the several steps in Nature's plan
for nourishing the embryo and fetus. In the first place, as we have
seen, there is the yolk sack or umbillical vesicle, filled with a fluid
which nourishes the embryo. This gradually disappears in time, and is
replaced by the "allantois" which by connection with the walls of the
Uterus is enabled to nourish the fetus from and by the blood of the
mother. For a short time, however, the embryo is nourished by both the
yolk sack and the allantois. Then the allantois assumes the entire task,
and the yolk sack passes away. Then, later, the placenta replaces the
allantois, and the latter passes away as did its predecessor. The
placenta works along the same general lines as the allantois, but is a
far more complex way and with a much higher degree of efficiency, as we
shall see presently.
The placenta is connected with the body of the fetus by what is known as
"the umbillical cord." The "umbillicus" or "navel" in the human being
marks the place at which the umbillical cord entered the body of the
fetus, from which it was severed after the birth of the child. The
purpose of the umbillical cord is to contain and support the umbillical
arteries and veins through which the fetus obtains nourishment from the
placental substance, and through which the return blood flows. The rich
red arterial blood is carried from the placenta to the fetus, and is
then distributed over the body of the fetus, nourishing and building it
up; the dark venous blood, laden with the waste products of the body of
the fetus, is carried back to the placenta, there to be repurified and
rendered again rich and nourishing.
The story of the circulation of the blood of the fetus is most
interesting. Although the fetal blood is derived from that of the
mother, as we have said, yet the maternal blood does not pass directly
from the circulatory system of the mother into that of the fetus; nor
does the blood of the fetus return directly into the circulatory system
of the mother. In fact, the fetal blood never comes in direct contact
with that of the mother, or vice versa. The fetus has an independent
circulatory system of its own, and yet, at the same time, from the
moment of the placental connection until the moment of childbirth, all
its nourishment is derived from its mother.
The secret of the above paradoxical statement is made apparent when we
understand the meaning of the scientific term "osmosis." Osmosis is "the
passage of a fluid through a membrane"; it is a chemical process, caused
by the chemical affinity between two liquids or gases separated one from
the other by a porous diaphragm or substance. In the process of osmosis
in the case before us, the fetal blood takes up nourishing substances
and oxygen from the blood of the mother, and passes on to the latter the
waste products of the fetal system, by means of passing these substances
through the thin porous membranes which separate the two independent
systems of blood vessels, i. e., the system of the fetus, and that of
the mother. Before birth, in fact, the fetus has its blood nourished and
oxygenated by means of the food partaken of by its mother, and the
oxygen taken in by the mother in her breathing. After its birth, the
infant eats and breathes for itself, and thus nourishes its blood supply
directly, instead of receiving it indirectly from the mother.
The Placenta begins to be formed about the third month of gestation, and
continues to develop steadily from that time. At the time of the
delivery of the child the Placenta covers nearly or quite one-third of
the inner space of the distended Uterus of the mother. The total
"afterbirth" consists of the Placenta, the umbillical cord, and the
remaining membranes of the ovum, all of which are expelled after the
birth of the child.
THE AMNION. An important appendage contained in the Uterus in connection
with the developing fetus is that known as "The Amnion." This is an
inner sack which forms within the womb, and which serves to enclose the
fetus, and also to sheath the umbillical cord. The Amnion encloses the
embryo very snugly during the early stages of its development, but it
gradually becomes distended with a pale watery fluid, known as "the
amniotic fluid," the purpose of which is to "float" the fetus and to
give it mechanical support on all sides. This fluid is composed of water
carrying in solution small quantities of albumin, urea, and salt.
SEX IN THE EMBRYO AND FETUS. It is impossible to determine the sex of
the embryo during its early stages. During the fourth week the first
traces of the sexual glands appear, but not until the fifth week can the
sex be determined even by the microscope. If the embryo is to become a
male, certain ducts are transformed into convoluted tubules, and each is
attached to the testes which have been formed from the genital nucleus.
If the embryo is to become a female, the ducts join to form the uterus
and vagina, other portions being transformed into the fallopian tubes
and connecting with the ovaries which have been formed otherwise. The
outer genitals appear in the early stages of the embryo, but there is no
apparent distinction between the sexes, the external organs being the
same in all cases, and consisting of a small tubular organ with a small
lateral fold of skin on either side. Later, in the male, a groove
appears on the under side of this primitive organ, thus forming the
urethra, the scrotum being formed from the folded skin at the side. In
the female, the primitive organ ceases to develop as in the male, and
thus becomes proportionately smaller, and evolves into the clitoris of
the female; the two lateral folds, on each side, being transformed into
the labia majora, or "outer lips" of the female external genitals.
POSITION OF THE FETUS. During the period of gestation the fetus lies
"curled up" in the bag of the amnion. The head is usually relaxed and
inclined forward, the chin resting on the breast; the feet are bent up
in front of the legs, the legs bent up on the thighs, the knees
separated from each other, but the heels almost touching on the back of
the thighs; the arms bent forward and the hands placed between them as
though to receive the chin between them. The folded-up fetus forms an
oval, the longest diameter of which is about eleven inches at its
greatest stage of growth. Nature here shows a wonderful ability to pack
the fetus into as little space as possible, and in such a position as to
protect it from injury, and to discommode the mother as little as
possible.
The following interesting statement made by Helen Idleson, M. D., in a
European medical journal several years ago, gives a very clear idea,
expressed in popular terms, of the appearance and characteristics of the
embryo or fetus in the various stages of its development:
"The growth of the embryo after fecundation is very rapid. On the TENTH
DAY it has the appearance of a semi-transparent grayish flake. On the
TWELFTH DAY it is nearly the size of a pea, filled with fluid, in the
middle of which is an opaque spot, presenting the first appearance of an
embryo, which may be clearly seen as an oblong or curved body, and is
plainly visible to the naked eye on the fourteenth day. The TWENTY-FIRST
DAY the embryo resembles an ant or a lettuce seed. Many of its parts now
begin to show themselves, especially the cartilaginous beginnings of the
spinal column, the heart, etc. The THIRTIETH DAY the embryo is as large
as a horse-fly, and resembles a worm, bent together. There are as yet no
limbs, and the head is larger than the rest of the body. When stretched
out it is nearly half an inch long. Toward the fifth week the heart
increases greatly in proportion to the remainder of the body, and the
rudimentary eyes are indicated by two black spots toward the sides, and
the heart exhibits its external form, bearing a close resemblance to
that in an adult. In the SEVENTH WEEK, bone begins to form in the lower
jaw and clavicle. Narrow streaks on each side of the vertebral column
show the beginning of the ribs. The heart is perfecting its form, the
brain enlarging, and the eyes and ears growing more perfect, and the
limbs sprouting from the body. The lungs are mere sacks, and the trachea
is a delicate thread, but the liver is very large. In the seventh week
are formed the renal capsules and kidneys.
"At TWO MONTHS, the forearm and hand can be distinguished, but not the
arm; the hand is larger than the forearm, but it is not supplied with
fingers. The distinction of sex is yet difficult. The eyes are
prominent. The nose forms an obtuse eminence. The nostrils are rounded
and separated. The mouth is gaping, and the epidermis can be
distinguished from the true skin. The embryo is from one-half to two
inches long, the head forming more than one-third of the whole. At the
end of THREE MONTHS, the eyelids are distinct but shut; the lips are
drawn together; the forehead and nose are clearly traceable, and the
organs of generation prominent. The heart beats with force; the larger
vessels carry red blood; the fingers and toes are well defined, and the
muscles begin to be developed.
"At the FOURTH MONTH, the embryo takes the name of 'fetus.' The body is
six to eight inches in length. The skin has a rosy color, and the
muscles produce a sensible motion. A fetus born at this time might live
several hours. At FIVE MONTHS the length of the body is from eight to
ten inches. At SIX MONTHS, the length is twelve and one-half inches. The
hair appears on the head, the eyes closed, the eyelids somewhat thicker,
and their margins, as well as their eyebrows, are studded with very
delicate hairs. At SEVEN MONTHS, every part has been increased in volume
and perfection; the bony system is nearly complete; length, twelve to
fourteen inches. If born at this period, the fetus is able to breathe,
cry and nurse, and may live if properly cared for.
"At EIGHT MONTHS, the fetus seems to grow rather in length than in
thickness; it is only sixteen to eighteen inches long, and yet weighs
from four to five pounds. The skin is very red, and covered with down
and a considerable quantity of sebaceous matter. The lower jaw, which at
first was very short, is now as long as the upper one. Finally, at term,
NINE MONTHS, the fetus is about nineteen to twenty-three inches long,
and weighs from six to eight pounds. The red blood circulates in the
capillaries, and the skin performs the functions of perspiration; the
nails are fully developed."
Another writer says: "There is a superstition that a child born at eight
months is not as liable to live as if born at seven months; indeed, many
suppose that an eight months' child never survives. Facts do not prove
this idea to be correct. Personally, I have known several eight months'
babies to live and do well, and I believe that their chance of life is
much greater than if born at seven months."
Children born in the seventh month of gestation are capable of living,
though great care is required to rear them for the first few months
after birth. The "incubators" now so common in large cities have greatly
increased the chances of the "seven months' child," and, for that
matter, of those born even earlier. There are a number of cases of
record where children have been born after six months of gestation, and
a few even before the six months, but these cases are rare and unusual,
and such children usually die soon after birth.
The following table, given by a good authority, shows the average length
and weight of the human embryo and fetus:
Age. Length in inches. Weight.
2 weeks 0.1 Not given
3 weeks 0.2 3 grains
4 weeks 0.3 Not given
5 weeks 0.5 Not given
6 weeks 0.7 Not given
7 weeks 0.9 Not given
8 weeks 1.5 4 drachms
3 months 3.0 2 ounces
4 months 6.0 5 ounces
5 months 9.0 10 ounces
6 months 12.0 1 pound
7 months 15.0 3 pounds
8 months 17.0 5 pounds
9 months 20.0 6 to 9 pounds
Professor Clark holds that if at birth the infant weighs less than 5
pounds, it rarely thrives, though the records show that many infants
weighing much less than this have lived and thrived. In very rare cases,
infants have been known to weigh no more than one pound at birth, and to
have still survived and thrived. And, on the other hand, many cases are
known where infants were born, and thrived, who weighed more than twice
the average weight. So, at the last, it is difficult to lay down hard
and fast rules in the case.
DELIVERY. At the termination of the period of gestation, the child is
born into the world, and, instead of depending upon the blood of the
mother for nourishment and oxygen, it begins to ingest its own food, to
eliminate its own waste matter through the regular channels of the body,
and to use its own lungs for the purpose of obtaining oxygen for its
blood and to burn up the waste products in the lungs.
The process of bringing a child into the world is called "parturition."
The fetus is expelled from the body of the mother by the contraction of
the muscles of and around the Uterus, and also by the contraction of the
abdominal walls. In the early stages of labor, the uterine muscles are
brought into play; but when the fetus enters into the vaginal passage
the abdominal muscles manifest their energy. The uterine and abdominal
muscular movements are purely involuntary, although the mother may aid
in the delivery by voluntary muscular movements. The involuntary
muscular movements are due to the reflex action originating, probably,
in a part of the spinal cord.
The uterine contractions are rhythmical, and have been compared to the
contraction of the muscles of the heart. Each "labor pain" begins with a
minimum of contraction, the activity increasing until a maximum is
reached, when it gradually decreases, only to be followed a little later
by a new contraction. When the fetus is finally expelled from the Uterus
(followed later by the placenta or "afterbirth") that organ begins a
gradual contraction to its normal size, shape, and condition, the
restorative process usually lasting over several weeks.
THE PHYSICAL SIGNS OF PREGNANCY. The physical signs of pregnancy in the
case of women of normal health are as follows:
(1) CESSATION OF THE MENSES, OR MENSTRUATION. While it is true that a
non-pregnant woman may occasionally pass over a menstrual period, yet as
a general rule the complete cessation of a period by a married woman,
particularly when the woman has previously been regular in this respect,
may be considered a probable indication of pregnancy; and when the
second period has been passed the probability merges almost into a
certainty. An examination by a competent physician will set all doubts
at rest.
(2) ENLARGEMENT OF THE BREASTS. This indication usually manifests itself
in about six or eight weeks after conception. This enlargement is
usually preceded by a sensation of tingling and throbbing. The
enlargement is manifested in the form of a rather hard and knotty
increase, differing from the ordinary fatty increase; the lobules,
arranged regularly around the nipple, are plainly distinguishable
beneath the skin by means of the touch of the fingers.
(3) DARKENING OF THE AREOLAR TISSUE SURROUNDING THE NIPPLE. In the
unimpregnated condition this tissue is of a pinkish shade; but after
impregnation the shade grows darker and the circle increases in size.
However, when the woman bears several children in somewhat rapid
succession, this dark color may become permanent and accordingly ceases
to be an indication.
(4) ENLARGEMENT OF THE ABDOMEN. This indication manifests itself about
the second month, at which time the Uterus begins to elevate the
intestines by rising up from the pelvis. In the fourth month the Uterus
has risen so far out of the pelvis that it assumes the form and
appearance of a hard round tumor. The entire abdomen then begins to
enlarge. The Uterus causes an enlargement in the region of the navel at
the sixth month, and the region of the diaphragm at the ninth month.
(5) QUICKENING, OR "SIGNS OF LIFE." This indication manifests first from
the fourth month to the fifth--at about the exact half of the entire
period of gestation. At this time, and afterward, the movements of the
embryo are plainly discernable to the mother.
THE DISORDERS OF PREGNANCY. There are a number of physical disorders
usually accompanying pregnancy, some of which are trifling, but some of
which require the advice of a competent physician. The best plan is for
the woman to consult a physician shortly after she discovers herself to
be pregnant, and thereafter to visit him occasionally for advice during
the period of gestation. The too common plan of postponing the call upon
the physician until the eighth or ninth month is not a wise one, for in
many cases the advice of a competent physician at an earlier stage of
the pregnancy will obviate serious complications. The call upon the
physician should usually be made not later than the third or fourth
month, and positively not delayed longer than the fifth month. The
physician should make an examination to ascertain whether the child is
in the normal position in the Uterus, and should also examine the urine
each month to ascertain whether the kidneys are functioning normally.
What is called "morning sickness" is one of the most common of the
disorders of pregnancy. It is marked by nausea or vomiting, or both,
early in the morning, usually shortly after arising. Some women have at
least faint symptoms of this disorder from the very beginning of
conception, but usually it does not manifest until the third, fourth, or
fifth week of pregnancy. It usually ceases at the end of the third or
fourth month. Except in very severe cases, in which the physician should
be consulted, the disorder is not serious, and requires but a little
common-sense treatment, and rational habits of living. An authority
says: "Eat of some fruit that best agrees with palate or stomach; drink
hot water; eat nothing until a real hunger demands food. Where nausea
occurs after eating, a tart apple or orange is good." Another authority
says: "Let women suffering from morning sickness try acid fruit--apples,
oranges, or even lemons, if their sourness is not unpleasant. If a
single orange or apple after each meal does not suffice, let them try
two; let them eat ten if that number is necessary to conquer the
distress. The principle is a correct one, and the relief certain. Let
fruit be eaten at all hours of the day--before meals and after, on
going to bed at night and at getting up in the morning. If berries are
in season, let them be eaten in the natural state--that is, without
sugar. If the sickness still continues, omit a meal now and then, and
substitute fruit in its stead. By persistence in this course, not only
will nausea be conquered, but an easy confinement guaranteed."
The pregnant woman often develops a capricious appetite. This disorder
may manifest in one or more of several forms, as for instance: the woman
may lose her appetite, and take but little food; or she may develop an
abnormally large appetite, and eat much more than is necessary; or she
may take a dislike to certain kinds of food--many women have an aversion
toward meat during pregnancy; or she may have a "craving" for certain
articles of food, sometimes for kinds of food not liked at other times,
such as sour pickles, sour cabbage, etc. A little common sense, and the
presence of attractive articles of fruits, etc., will do much to relieve
these troubles; in extreme cases the physician's advice will help.
The pregnant woman should have her teeth put in good order as soon as
possible, as troubles with teeth sometimes manifest themselves during
pregnancy, and give much trouble and annoyance. Difficulty in urination,
constipation, piles, irritation or itching of the genital organs,
varicose veins, liver spots, and similar disorders, which are sometimes
manifest during pregnancy, in some form or degree, should receive the
attention and care of a competent physician.
The following general advice from a competent authority is worthy of
being followed: "If everything is satisfactory, if there is no severe
vomiting, kidney trouble, etc., the usual mixed diet may continue. The
only changes I would make are the following: Drink plenty of hot water
during the entire time of pregnancy: a glass or two in the morning, two
or three glasses in the afternoon, the same at night. From six to twelve
glasses may be consumed. Also plenty of milk, buttermilk and fermented
milk. Plenty of fruit and vegetables. Meat only once a day. For the
tendency to constipation, whole wheat bread, rye bread, bread baked of
bran, or bran with cream. As to exercise, either extreme must be
avoided. Some women think that as soon as they become pregnant, they
must not move a muscle; they are to be put in a glass case, and kept
there until the date of delivery. Other women, on the other hand, of the
ultra-modern type, indulge in strenuous exercise, and go out on long
fatiguing walks up to the last day. Either extreme is injurious. The
right way is moderate exercise, and short, non-fatiguing walks. Bathing
may be kept up to the day of the delivery. But warm baths, particularly
during the last two or three months, are preferable to cold baths."
CHILDBIRTH. The first indication of approaching delivery of the child is
that of the descent of the child into the pelvis of the mother, from its
former position up near the diaphragm. When this occurs, the mother
usually experiences a feeling of relief, and a greater ease in breathing
because of the relaxation of the former pressure on the diaphragm.
Sometimes this occurs several days preceding delivery, while in other
cases it occurs only a few hours before delivery. There usually occurs
about the same time a slight discharge of mucus tinged with blood. The
latter is called "the show," and is caused by the unsealing of the mouth
of the womb, and indicates that the Uterus is preparing to discharge its
contents.
Labor, in childbirth, consists of three stages. In the first stage, the
Uterus alone contracts, and the mouth of the womb dilates; in the second
stage, the abdominal muscles assist the Uterus in expelling the child;
in the third stage, the Placenta (afterbirth) and membranes are
expelled.
After the delivery of the child, and after the pulsation in the
umbillical cord has ceased (usually from ten to thirty minutes after
delivery), the umbillical cord is severed and tied by the physician. In
natural labor, the expulsion of the afterbirth occurs from within a few
minutes to an hour after the delivery of the child. Nature is sometimes
slow in expelling the afterbirth, but caution should be exercised in the
matter of using force to assist Nature in this matter, for injury to the
Uterus has often resulted from malpractice in such a case. The
afterbirth is not firmly attached to the womb, but is like the peel of
an orange which Nature sloughs off in due time.