presence of tiny glands always located there which, on account of the
better state of nutrition during pregnancy, grow larger, and
generally become visible.

Usually, after two menstrual periods have been missed the breasts
increase in size and firmness, and often the veins which run just
beneath the skin stand out conspicuously. Before very long it is
possible to squeeze from the breasts a fluid which many persons
believe to be milk, though it is really colostrum, a substance that
resembles milk but very slightly. At first colostrum is a clear,
white fluid, but in the later months of pregnancy it becomes yellow
and cloudy.

None of the changes in the breasts are absolutely characteristic of
pregnancy; even the secretion of colostrum has been noted in
association with various other conditions. Furthermore, as a sign of
pregnancy the presence of colostrum is totally deprived of value in
the case of a woman who has recently nursed an infant, for a small
quantity of milk or colostrum often remains in the breasts for months
after the infant is weaned. In general, however, women who have not
been pregnant before should assume that they have conceived if, after
missing a menstrual period, they note the characteristic changes in
the breasts.

_Morning Sickness_.--Soon after conception many women suffer
from nausea and vomiting, especially on rising in the morning.
"Morning sickness" usually passes off in a few hours, although it may
be more persistent. Perhaps this manifestation occurs more frequently
in the first than in subsequent pregnancies, but certainly one-half,
and probably two-thirds, of all prospective mothers suffer from it.