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[205 The Course of Labor]

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[Narrator:] Toward the end of pregnancy,

as you wonder whether to get ready for a baby girl

or a baby boy,

nature is awaiting the precise moment

to start the birth process...

a process which is called labor.

Since the signal that things are starting may be

only a slight twinge,

some understanding

of the process of labor will help you

recognize when true labor is underway

and what takes place during the hours that

follow as your baby is born.

The word "labor" is also used to describe

the work of your uterine muscles as they contract

during the birth process.

Some call these contractions labor pains and vice versa.

Some call pains contractions.

Throughout pregnancy, your uterus or womb

has served to contain your growing baby.

The lower portion or cervix has been sealed with a mucous plug.

Inside, the sac of amniotic fluid

has cushioned your baby, whileyour placenta and umbilical

cord have nourished it.

When labor starts, the uterine muscles

above your cervix that have been stretched around your baby

will start to contract back toward normal.

These contractions provide the major work force needed

to give birth to your baby.

But several weeks before this happens,

your baby gradually moves downward

into a more favorable position for birth.

This change is called dropping or lightening.

You'll be able to breathe easier,

since there is more room for your diaphragm.

However, because of the increased pressure

of your baby on your bladder,

there is a tendency for you to urinate smaller amounts more often.

During the same period, you may be

more conscious of cramp-like pains

in the lower part of your abdomen or groin.

These are the same contractions that you normally

feel throughout pregnancy,

only now

they're likely to get stronger, and they may be painful.

But remember, if your contractions have

no regular pattern, and even if they last for a few hours,

if they go away, they were false labor pains.

Yet, these contractions are useful,

nature's way of softening your cervix

and getting your uterine muscles ready for the task ahead.

Then when the actual birth of your baby

is near, and probably at a time when you least expect it,

true labor will begin. Meaning that the birth

process has begun.

Yet, occasionally, there are certain clues

that labor is about to start.

You may notice a discharge of blood-tinged mucus

from your vagina.

This bloody show usually means that labor will

begin within the next 48 hours.

Sometimes, the bag of waters breaks

before the start of labor.

Anything from a gush to a steady trickle of fluid

must be reported with the expectation

that you will be going to the hospital.

But what usually happens first are the true pains of labor.

How can you recognize true labor?

The answer is that time will tell.

The first pains may be centered low in the back

or resemble menstrual cramps.

But unlike false labor, the pains do not go away.

Instead, they become progressively stronger, 

more regular, and more frequent.

Therefore, it is important that you time your contractions.

Do not guess.

Use a watch with a second hand, and write down

how long each pain lasts and how far

apart the pains are so you can report

this information accurately.

For practical purposes, if your pains are strong,

last 30 seconds or longer, and occur regularly

eight to ten minutes apart, you may be reasonably sure

true labor is underway.

When you are told to leave for the hospital,

do not eat or drink anything.

Your stomach should be empty during labor and delivery

as a precaution against vomiting or other complications.

Although every woman has a slightly different story

to tell about her experience, the course of labor,

once started, continues involuntarily

through three stages.

The first stage of labor dilates or opens

the cervix in preparation for delivery.

If this is your first baby, this may

take from eight to 14 hours, during which time

your contractions get progressively

stronger and closer together.

The second stage of labor delivers the baby.

This may take an hour or more.

The third stage of labor expels the placenta, or afterbirth,

and this rarely takes longer than 15 minutes.

To complete the first stage of labor,

certain things must take place, 

even though they may occur at different times

for different women.

The upper portion of your uterus becomes the active

contracting portion, and your cervix becomes passive.

As the active portion contracts,

it pulls or takes up the lower portion.

Gradually, as your cervical canal

is shortened and thinned out, a process

known as effacement, the mucus that has been sealing off

your cervix is dislodged.

Once the cervix is effaced and there is no longer a canal,

the external opening left in the membrane

begins to enlarge or dilate.

Within a short time, the dilatation

reaches about four inches, and your cervix

ten forms a smooth passageway with your vagina.

If your fluid-filled sac or bag of waters hasn't already

broken, it will usually rupture or be broken at this time,

and you'll feel a clear warm fluid pass from your vagina.

With the cervix dilated and the fluid in front of the baby's

head lost, your baby can then begin

the beautifully coordinated movements

of the second stage of labor.

It is during this stage that you will bear down,

that the muscles of your abdomen, as if by reflex action,

will help with the delivery.

Following its engagement within your pelvis,

your baby's head flexes forward to where

its chin rests on its chest.

Then each aspect of the descent is characterized

by the baby's head shifting or turning

to conform to the shape of your birth canal.

Molding of the head is possible because the bones of the skull

have not yet united and can therefore overlap

or compress during the descent.

As labor progresses, the back of your baby's head

pivots under your pubic bone, 

which serves to extend it upward toward your vaginal opening.

Finally, your vulva bulges, then parts, and the head is born.

Within the next minute or so, the head and body turn,

the uppermost shoulder slips from under the pubic bone,

and the rest of the body is born.

While the umbilical cord is cut, the placenta or afterbirth

remains in the lower part of the uterus waiting

to be expelled during the third stage of labor.

Although the active portion of your uterus

has shrunk to almost a solid mass of muscle

around the placenta, there continue

to be mild contractions.

Once separated from the uterus, your placenta,

aided by slight pressure on your abdomen,

passes from your vagina to complete the birth process.

For the next few days, your uterus

can be felt as a hard mass in the lower abdomen.

Then during the next six weeks or so

it shrinks from an organ about the size of a grapefruit

to that of a small pear.

And, of course, one of the nicest things

about getting back to normal is getting back to a flat tummy.

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