$Unique_ID{PAR00403}
$Pretitle{}
$Title{Pregnancy:  The First Month:  Your Changing Body}
$Subtitle{}
$Author{
Editors of Consumer Guide
Ellis, Jeffrey W
Ellis, Maria}
$Subject{First Month Changing Body pregnant pregnancy menstrual period cycle
hormone hormones estrogen progesterone ovary ovaries uterus fertilized egg
sperm placenta vaginal discharge bleeding spotting nausea nauseous nauseated
vomit vomits vomiting morning sickness human chorionic gonadotropin urinate
urinates frequently bladder}
$Log{
Your Changing Body (First Month)*0040301.tif
28-Day Embryo*0060201.tif}

Miracle of Birth


The First Month:  Your Changing Body


     Perhaps the first thing you will notice when you are pregnant is that you
have missed your menstrual period.  During a normal menstrual cycle, the
hormones estrogen and progesterone, which are produced by your ovaries, cause
a buildup of tissue and blood vessels in the inner walls of your uterus.  This
is the body's way of preparing for the fertilized egg if you should become
pregnant.  If your egg is not fertilized by a sperm, the thickened lining of
your uterus is sloughed away at the end of the month and you have a menstrual
period.  If your egg is fertilized, however, the lining of the uterus does not
slough away.  Instead, it grows even thicker and forms the attachment for the
placenta (the organ that develops on the inner wall of the uterus to supply
nutrients to your baby and carry the baby's waste products back to your body
to be excreted).
     While you are pregnant, you will not have periods.  During the first
month of pregnancy, however, some women will notice very slight bleeding or
light brown vaginal discharge at the time of the month when their period would
usually occur.  This is quite normal and is thought to be a result of the
implanting of the placenta in the inner wall of the uterus.  If you notice any
bleeding after the first month, however, you should report it to your doctor
immediately.
     When you visit your doctor for the first time during your pregnancy, you
will be asked for the date that your last normal menstrual period began.  This
date is used to calculate the due date for your pregnancy.  If possible, keep
careful track of the dates of your last normal menstrual period and any other
episodes of bleeding or spotting.  This will help eliminate errors in
calculating your due date (see next section for more on calculating your due
date).
     Another sign that may indicate that you are pregnant is the sudden onset
of nausea and vomiting--commonly called morning sickness.  About two-thirds of
all pregnant women experience this type of discomfort.  It commonly occurs in
the morning (hence its name) but may also develop at any time of the day.
Morning sickness may be triggered by a hormone called human chorionic
gonadotropin, which is produced by the placenta:  however, emotional factors
and even unpleasant odors may also play a role.  Fortunately, morning sickness
is usually easy to control (see The First Trimester:  Coping, a further
section) and generally does not last beyond the first trimester.  If you
experience severe morning sickness, however, your doctor may have you modify
your diet or may prescribe medication to relieve the nausea and vomiting.
     Another change that you are likely to notice is the need to urinate more
frequently, sometimes even during the middle of the night.  When you are not
pregnant, your uterus lies wholly within the bony cavity of the pelvis.  The
bladder, which stores your urine, lies in front of the uterus, also within the
pelvic cavity.  As your uterus enlarges during the first trimester, it pushes
against the bladder and decreases the bladder's capacity to hold urine.  As a
result, you will urinate more frequently and usually in smaller amounts.
During the second trimester, the uterus grows upward into the abdominal
cavity, relieving the pressure on your bladder and allowing you to urinate
less frequently.