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