Normal Labor and DeliveryPhysiological Adaptations

Presented by Ann Hearn

LABOR

The Process by

which the Products of

Conception are expelled

from the body

Essential Factors in Labor

Passenger

PowersPassageway

Psychological

THEPASSAGEWAY

THE PELVIS

Determine if the pelvic cavity is of adequate size to allow for the passage of the full term infant

Optimum shaped pelvis is Gynecoid

THE PELVIS

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

True Pelvis vs. False Pelvis

True Pelvis Inlet - upper margin of pubic bone to

upper margin of sacrum

Outlet - Lower pubic bone to tip of coccyx. This area is the smallest portion that the baby must travel through.

THE

PASSENGER

And

PPRESENTATION

Fetal HeadFetal Head

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

Fetal Lie

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

Longitudinal Lie Transverse Lie

True or False?

The optimum lie of the fetus is the longitudinal lie.

A. True B. False

Fetal Presentation

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

Three Types:Cephalic

Vertex, Face, BrowBreechShoulder

Cephalic = Occiput, posterior fontanel

Breech = Sacrum

Face = Mentum

Reference Points

Attitude

Relationshipof fetal body parts toeach other

Optimumattitude isflexion or ovoid

POSITION

POSITION

Relationship of the Fetal Presenting Part to the Maternal Pelvis

Steps: 1. Determine the Presenting Part 2. Divide the mothers pelvis into 4 imaginary quadrants

A

P

12

L3

6

9R

ENGAGEMENT

Descent of the fetal presenting part in relation to the ischial spines of the maternal pelvis = 0 station.

Engagement

Engagement -largest diameter of

presenting part has passed through the pelvic inlet

- Assessed during vaginal exam

Ballotable

Engaged

Station

Station- degree that the presenting part has

descended into the pelvisin

Relationship to ischial spines

Goal• Move from – to + stations

Test Yourself !

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

THE

POWERS

Major Powers Involved

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 Powers Abdominal muscles assist in the Second Stage

of Labor with pushing. Increase intra-abdominal pressure to aid in expulsive forces

THE

PSYCHOLOGICAL

FEARFEARTENSIONTENSION

PAINPAIN

BREAK THE CYCLE !

Techniques for Assessment

Abdominal Palpation / Leopold’s Maneuver Standing on the Right side, face the woman and

palpate with the palms of the hands. Step 1 - Start at upper fundus and palpate for the

head or buttocks Step 2 - Go down each side and locate back Step 3 - Gently grasp lower portion of uterus and

feel for the head or buttock Step 4 - Turn and face the woman feet, using both

hands palpate lower abd. for cephalic prominence or brow.

Ausculation

Assess for the area of greatest intensity of the FHR.Usually best heard at the fetal back

True or False ?

If the fetal heart tones (FHT’s) are heard loudest (PMI) in the patient’s upper right quadrant of her abdomen, the fetus would be assessed for a breech presentation.

A. True B. False

Vaginal Examination

Presentation – presenting part (head/buttock)

Position – fetal head (OA, OP etc.)Condition of Membranes – ruptured or

intactDilation - enlargement & widening of os (cm)Effacement – thinning of the cervix (%)

Vaginal Examination

Station- degree that the presenting part has descended into the pelvis. Relationship to ischial spines (-, 0, +)

Engagement -largest diameter of presenting part has passed through the pelvic inlet

Station

Station- degree that the presenting part has

descended into the pelvisin

Relationship to ischial spines

Goal• Move from – to + stations

Critical Thinking

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?

Try this ! When the cervical os widens or opens it is said

to________.

The level of the ________ _________ (bony structure) 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 accommodate to this rigid passageway______________.

CAUSES OF LABOR

Increase in EstrogenDecrease in Progesterone

Degeneration of Placenta

Over-distention of Uterus

High levels ofProstaglandins

Myometrial ActivityMyometrial Activity

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

FORCES OF LABOR

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

Incremen

tacme

Decrement

FORCES OF LABOR

Incremen

t acme

DecrementDuration

Frequency

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

another contraction

Interval

Interval - Resting time between contractions for placental perfusion

Uterine Contraction - review

Fill in the blank ! 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 ____.

When the biparietal diameter of the head passes through the pelvic inlet it is said to be ________.

Assessment of Contraction

1. Subjective symptoms by woman

2. Palpation and timing by the nurse

3. Use of Electronic Fetal Monitor (EFM)

Duration of Labor

Resistance of the Cervix Presentation and position of the

fetus, The woman’s pelvis Preparation and relaxation of the

mother Primigravida - up to 22 hrs; average 12 1/2 hrs Multigravida - 8 - 17 hrs; average 10 hrs.

Premonitory Signs of Labor

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

Premonitory Signs of Labor

LIGHTENING

FALSE LABOR PAIN (Braxton Hicks)

SHOW

Rupture of Membranes (ROM)

BACKACHE

DIARRHEA

SUDDEN INCREASE IN ENERGY

True vs. False Labor

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

* No change or decrease with walking* Contractions felt in abdomen above umbilicus Braxton Hicks

No change in cervix Fetus is ballotable

Phases and Stages of Labor

Stage 1: 0 - 10 cm. Phase 1 - Latent - dilate 0 - 3 cm. Phase 2 - Active - dilate 4 - 7 cm. Phase 3 - Transition - dilate 8 - 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

Signs of Second Stage of Labor

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

Mechanisms of Labor/ Cardinal Movements

Signs of Stage Three of Labor

The End

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