$Unique_ID{PAR00425}
$Pretitle{}
$Title{Pregnancy:  The Sixth Month:  Your Changing Body}
$Subtitle{}
$Author{
Editors of Consumer Guide
Ellis, Jeffrey W
Ellis, Maria}
$Subject{Sixth Month Changing Body heartburn hormone hormones progesterone
skin stretch mark marks hyperpigmentation Estrogen dark pigment areola
chloasma linea nigra Braxton Hicks contraction contractions uterus}
$Log{
Your Changing Body (Sixth Month)*0042501.tif
25-26 Week Fetus, male*0060212.tif}

Miracle of Birth


The Sixth Month:  Your Changing Body


     Several changes will occur in your body during the sixth month of
pregnancy, and, as before, they will be caused by your increasing hormone
levels and your enlarging uterus.
     By now, you will probably have experienced heartburn.  This is a normal
discomfort of pregnancy and occurs for several reasons.  First, the hormone
progesterone slows the action of the entire digestive system, including the
stomach.  Since it now takes a longer time for the stomach to empty its
contents into the intestines below, there is more chance of an upward
flow--or regurgitation--of food back up into your esophagus (the tube through
which food travels from your mouth to your stomach).  This food, which is
mixed with stomach acids, is highly irritating to the esophagus.  It is this
irritation that causes you to have the burning sensation in the middle of your
chest.
     The second reason you may experience heartburn has to do with the tight
band of muscle, called a sphincter, at the point where the esophagus connects
to the stomach.  Normally, this band of muscle tightens after you eat and
prevents food from re-entering your esophagus.  The increase in the level of
progesterone that occurs during pregnancy, however, can cause this sphincter
to weaken, allowing further regurgitation of food.
     Finally, as your uterus enlarges, it pushes up firmly against the
stomach and may actually force food up into the esophagus.
     You may also be noticing several additional changes in your skin.  The
first of these are stretch marks, which may begin to develop on your abdomen,
breasts, and thighs.  These slightly indented, silvery-red streaks are the
result of ruptured fibers in the skin caused by the enlarging uterus, the
increase in breast tissue, and the increased accumulation of fat in the
thighs.
     Not all pregnant women develop stretch marks.  The tendency to develop
stretch marks seems to run in the mother's side of the family.  To get an idea
of whether you will develop stretch marks and to what extent, look at your
mother or sisters.  If they didn't develop stretch marks during pregnancy,
then there is a good chance that you won't either, and vice versa.  Any
stretch marks that do develop will gradually fade into thin, silvery lines
within a few months after delivery.
     Another common skin change of pregnancy is hyperpigmentation.  Estrogen
produced by the placenta indirectly stimulates skin cells to produce
increasing amounts of dark pigment.  This pigment then causes darkening of the
skin in certain parts of your body.  The areola, the dark skin that surrounds
the breast nipple, usually becomes darker.  Blotchy, brown patches--called
chloasma or "mask of pregnancy"--often develop on the face.  You may also
notice a dark line, called linea nigra, running down the middle of your
abdomen from your navel to your vagina.  These pigment changes almost always
fade away after delivery.
     During the sixth month of pregnancy, you will also probably begin to
notice occasional contractions of your uterus.  These so-called Braxton Hicks
contractions (named after Dr. Braxton Hicks, an English physician who first
described them) are transient, irregular, and nonpainful contractions of the
uterus (unlike the stronger, more frequent, and painful contractions that
signal labor).  You may first notice these as a tight feeling in your lower
abdomen.  Braxton Hicks contractions will occur throughout the remainder of
pregnancy and will generally become more frequent.