In the first pregnancy the passage of gas through the intestines may
be mistaken for quickening long before the movements of the child are
really perceptible; but those who have once experienced quickening
will not be deceived. Whenever women who have borne children are in
doubt the sensation is almost surely not quickening. Furthermore, in
any doubtful case, the motion should be observed by a physician
before being accounted a positive sign of pregnancy. This precaution
will scarcely delay an absolutely positive diagnosis, since the
proper method of examination reveals these movements to the physician
almost as early as the patient feels them.

About the time these movements become perceptible another positive
sign is available. The physician whose ear has been trained to catch
such sounds when he listens over the lower part of the mother's
abdomen will hear the fetal heart-beat. Other sounds may be audible
there, but the character and the rate of the heart-sounds are
distinctive. Since the child's heart beats almost twice as fast as
the mother's, under ordinary conditions it is impossible to confuse
one with the other. The mother never feels the beating of the child's
heart, but occasionally she will mistake for it the throbbing of her
own blood vessels.

Ability to hear the fetal heart not only provides a means of
confirming the existence of pregnancy in doubtful cases, but also
enables the physician to reassure his patient if she fails
temporarily to feel the child move. Sometimes the presence of twins
is recognized in this way. Toward the end of pregnancy the heart
sounds are also of material assistance in determining what position
the child has permanently assumed.