Chapter 17

LABOR

The Process by

which the Products of

Conception are expelled

from the body

Contraction-exhibits a wavelike pattern that begins slowly climbing (increment) to a peak, and decreases (decrement)

Incr

emen

tpeak

Decrement

Duration

Frequency

Duration- from beginning of one contraction to the end of the same contraction

Frequency- from beginning of one contraction to the beginning of another contraction

Interval

Interval - Resting time between contractions for placental perfusion

These lead to downward progression of fetus with each contraction

Effacement- thinning of the cervix (%)Dilation – enlargement and widening of the os (cm)

During each contraction, blood flow to the placenta gradually decreases, causing an increase in the woman’s blood volume causing her B/P to increase and slowing of her pulse.

Because these changes occur during a contraction, it is best to assess vital signs between contractions.

During labor a woman is likely to hyperventilate causing:◦ Tingling in hands and feet◦ Numbness◦ Dizziness

Have the woman slow her breathing or breath into a paper bag.

Most woman are limited to clear liquids or NPO during the labor process.

Gastric motility and digestion of food is reduced. Decrease risk of aspiration

Inhibit fetal descent

Most woman lose ~ 500ml blood during a vaginal delivery and ~1000ml during a cesarean birth.

Clotting factors are elevated and Fibrinolyis is decreased to promote coagulation at the placental site

Involuntary Uterine Contractions or Primary Powers

Muscular contractions which lead to dilation and effacement in the First Stage of Labor

Voluntary Uterine Contractions or Secondary Pushing Powers

Abdominal muscles assist in the Second Stage with pushing. Increase intra-abdominal pressure to aid in expulsive forces

Length of a uterine contraction__________.

Strength of a uterine contraction is ___________.

The time from the beginning of one contraction to the beginning of the next contraction is _______.

The time that allows for placental perfusion is __.

The peak of a contraction is also known as ____.

The Birth PASSAGE

False Pelvis Supports the

weight of the uterus

Shallow basin above the inlet or brim

True Pelvis Represents the bony limits of the birth canal

Inlet Inlet - upper margin of pubic bone to

upper margin of sacrum Outlet Outlet - Lower pubic bone to tip of coccyx. This area is the

smallest portion that the

baby must travel through.

Which has the greatest

impact on labor?

Which has the greatest

impact on labor?

Because of its size and rigidity, the Fetal Head has a major impact on delivery. The bones are not firmly united. There are sutures between the bones that allow them to overlap or MOLD to the birth canal.Head also can rotate, flex, and extend

Relationship of the long axis of the fetus to the long axis of the mother.

Longitudinal Lie Transverse Lie

AttitudeRelationshipof fetal body

parts toeach other

Optimumattitude is ovoid

The head is flexed forward, with the chin almost resting on the chest. The arms and legs are flexed.

The optimum lie of the fetus is the longitudinal lie.

A. True B. False

That portion of the fetus that enters the Pelvis first and covers the internal os.Three Types:

CephalicVertex, Face, Brow

BreechShoulder

Cephalic PresentationThe head is

entering the pelvis first.

Cephalic = Occiput, posterior fontanel

Breech = Sacrum

Face = Mentum

Reference Points

Relationship of the Fetal Presenting Part to the Maternal PelvisSteps: 1. Determine the Presenting Part 2. Divide the mothers pelvis into 4 imaginary quadrants

A

P

12

L3

6

9R

FEARFEAR

TENSIONTENSION

PAINPAIN

BREAK THE CYCLE !

The impending signs that take place the last several weeks of pregnancy or even the last several days

LIGHTENING

BRAXTON-HICKS CONTRACTIONS

CERVICAL CHANGES

SHOW

ROM

BACKACHE

SUDDEN INCREASE IN ENERGY

Weight loss

TRUE LABOR Contractions are: * Regular *Increase in intensity and duration with walking

*Felt in lower back, radiating to lower portion of abdomen

Bloody show Dilation and

effacement Fetus usually engaged

FALSE LABOR Contractions are irregular

Often stop with walking

Contractions felt in abdomen above umbilicus (abdominal pains)

No change in cervix

Fetus is ballotable

Engagement -largest diameter of

presenting part has passed through the pelvic inlet

- Assessed during vaginal exam

Ballotable

Engaged

Station- degree that the presenting part has descended

into the pelvisin

Relationship to ischial spines

Goal• Move from – to + stations

Stage 1 – From 0 cm. dilated to 10 cm.Stage 2 - From complete dilation and

effacement to delivery of the baby

Stage 3 - From delivery of baby to the delivery of the placenta

Stage 4 - the first hour after delivery

Latent Phase – is from 0 to 3 cm. dilated

Active Phase – is from 4cm. to 7 cm.

Transition Phase – is from 8 cm. to 10 cm.

Complete dilatation of cervixUrge to bear downPerineum begins to bulge, flatten and move anteriorlyIncrease in bloody show Rectal pressureLabia begins to part with each contraction

What is the reference point of a cephalic presentation when the head is fully flexed?A. occiputB. mentumC. frontald. sagittal

Overlapping of the fetal skull to facilitate its passage through the bony pelvis is ___________.Relationship of fetal body parts to each other is_____________.Head first presentation is_________________.Relationship of the fetal spine to the maternal spine is ________________.Term that refers to the part of the fetus that enters the pelvic inlet first is _____________.

Test Yourself

If the fetal head did not descend through the pelvis and stayed at the same station for a prolonged period of time, what do you think would be the treatment of choice?

When the cervical os widens or opens it is said to________.

The level of the ________ _________ is station zero.

The most common type of pelvis for a woman ___________.

When the cervix shortens and thins is _______________.

For delivery to occur, the fetus must accomodate to this rigid passageway______________.

The End