has been passed, it will be helpful even at the cost of repetition to sum up
what we know in explanation of such unfulfilled predictions. They are to be explained
sometimes by uncertainty as to the beginning of pregnancy, as for example by the
supposition that conception took place shortly after the last menstrual period, whereas it
actually occurred two or three weeks later. In a few instances, however, errors of
observation or of calculation will not account for false predictions.
It is generally admitted that second pregnancies average somewhat longer than first
pregnancies; one series of statistics indicates that the duration increases slightly with each
pregnancy up to the ninth and decreases after that. Pregnancy is protracted more
frequently in healthy women than in those who are not, and again more frequently in
those who are inactive than in those who work. With twins, contrary to the popular belief,
pregnancy is apt to end before, not after, the expected date. The sex of the child, in all
probability, has no influence upon the duration of pregnancy.
As we might expect, individuality is also a factor in this problem. Thus, the period of
gestation with some women is regularly longer, with others habitually shorter than the
accepted average. Until experience has demonstrated their existence, generally, such
peculiarities are overlooked. But occasionally they may be detected from knowledge of
the interval between the menstrual periods; an unusually long interval between them, for
example, would lead us to anticipate a protracted pregnancy.
Any delay after the expected date of birth has arrived taxes the patience of the
prospective mother. The fact, however, that more than 280 days have passed since the
last menstruation, does not necessarily mean that a patient has gone "over time." Such a
question can be decided solely from the weight and length of the child. Judged in this
way, comprehensive statistics indicate that once in several hundred cases pregnancy may
be fairly called prolonged. Even in these rare instances an examination about the time of
the predicted date makes it clear whether pregnancy should be artificially ended or be
allowed to proceed to its natural conclusion.
CHAPTER II
THE DEVELOPMENT OF THE OVUM
The Germinal Cells--Fertilization--The First Steps in Development-- The Reaction of the
Uterus--The Amniotic Fluid--The Placenta--The Umbilical Cord.
Pregnancy, besides changing the external form of the body, causes sensations--as for
example those due to fetal movements--which are so distinctive that they cannot escape
notice. These obvious evidences of approaching motherhood naturally lead thoughtful
women to wonder about the hidden mechanism of development, a mechanism which, of
itself, causes no sensation whatever. It is for this reason, perhaps, that a prospective
mother's imagination is so apt to be unusually active, often picturing absurd conditions as
responsible for one symptom or another. Those who give free play to the imagination in
regard to the formation and progress of the embryo are pretty certain to arrive at
erroneous if not grotesque conclusions; for example, they may attribute a protracted
pregnancy to the child's having grown fast to the mother, a situation that cannot arise.
Of course it is not essential that a prospective mother should understand what is
happening within the womb. And upon those who prefer to be ignorant of the mechanism
of development I would not urge another point of view, for not ignorance but the
unchallenged acceptance of "half-truths" and of totally incorrect explanations is the chief
source of harm. On the other hand, my own experience has taught me that women who
wish to know about development should be told the truth. In accord with this is the fact
that I never have more satisfactory patients than those who have previously been trained
nurses and who, in preparing for that profession, received instruction concerning the
reproductive function of human beings.
A description of development, in order to be perfectly clear, must begin with a word
about the fundamental structure of the adult body. Everyone knows that the various parts
of the body perform different functions; but not everyone, perhaps, realizes that, in spite
of their different functions, all the organs of the body are composed of similar structural
units, known as cells. Of course, cells are definitely arranged according to the use for
which the tissue that they chance to compose may be designed; they have, moreover,
distinctive individual peculiarities which can be easily recognized under the microscope;
but the essential features of the cells remain the same, wherever they may be located.
That is to say, each cell is a minute portion of living matter, or protoplasm, separated
from its neighbors by a partition, the cell-membrane; each has its own seat of government,
the nucleus, located near its center; and each, to all intents and purposes, leads an
individual existence.
THE GERMINAL CELLS.--Many
![](qr/20730/9.png)
Continue reading on your phone by scaning this QR Code
Tip: The current page has been bookmarked automatically. If you wish to continue reading later, just open the
Dertz Homepage, and click on the 'continue reading' link at the bottom of the page.