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LABORLABOR

Labor is a series of rhythmic, progressiveLabor is a series of rhythmic, progressive

contractions of the uterus that gradually movecontractions of the uterus that gradually move

the fetus through the lower part of the uterusthe fetus through the lower part of the uterus

(cervix) and birth canal (vagina) to the outside(cervix) and birth canal (vagina) to the outside

world.world.

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The Physiology ofLaborThe Physiology ofLabor

POSSIBLE CAUSESOFPOSSIBLE CAUSESOF

LABORONSETLABORONSET

Progesterone WithdrawalProgesterone Withdrawal

HypothesisHypothesis(Blackburn, 2003)(Blackburn, 2003)

Prostaglandin HypothesisProstaglandin Hypothesis

(Meadows, Eis, Brockman, &(Meadows, Eis, Brockman, &

Myatt, 2003)Myatt, 2003) CorticotropinCorticotropin--ReleasingReleasing

HormoneHormone

(Mc(Mc--Grath & Smith, 2001)Grath & Smith, 2001)

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Factors AffectingFactors Affecting

Labor(5 Ps)

Labor(5 Ps) 1.PASSENGER1.PASSENGER

2. PASSAGEWAY2. PASSAGEWAY

3. POWERS3. POWERS

4. POSITION4. POSITION

5. PSYCHE5. PSYCHE

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1.PASSENGER- the size,the size,

presentation and positionpresentation and positionof the fetus.of the fetus.

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ATTITUDE:ATTITUDE: This refers to theThis refers to the

posturing of the joints and relationposturing of the joints and relation

of fetal parts to one another.T

heof fetal parts to one another.T

henormal fetal attitude when labornormal fetal attitude when labor

begins is with all joints in flexion.begins is with all joints in flexion.

LIE:LIE: relationship of cephalocaudalrelationship of cephalocaudal

axisaxis (fetal spine(fetal spine) of the fetus to the) of the fetus to the

cephalocaudal axis of the mothercephalocaudal axis of the mother((maternal spine)maternal spine) i.e., transverse,i.e., transverse,

oblique, or longitudinal (parallel).oblique, or longitudinal (parallel).

PRESENTATION:PRESENTATION: This describes theThis describes the

part on the fetus lying over the inletpart on the fetus lying over the inletof the pelvic or at the cervical os.of the pelvic or at the cervical os.

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Types of PresentationTypes of Presentation

1.1.CEPHALICCEPHALIC = the fetal head= the fetal headpresents itself to the passage,presents itself to the passage,occurs in 97% of birthsoccurs in 97% of births

Classified as:Classified as:

1.1. VertexVertex most common;most common;fetal head is completely flexed;fetal head is completely flexed;

smallest diameter of the fetal headsmallest diameter of the fetal head(suboccipitobregmatic ) presents(suboccipitobregmatic ) presentsto the maternal pelvisto the maternal pelvis

2.2. MilitaryMilitary fetal head isfetal head isneither flexed nor extended; top ofneither flexed nor extended; top ofthe head is the presenting partthe head is the presenting part

3.3. BrowBrow fetal head isfetal head ispartially extended; sinciput is thepartially extended; sinciput is thepresenting partpresenting part

4.4. FaceFace fetal headfetal headcompletely extended; face is thecompletely extended; face is the

presenting partpresenting part

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2.2. BREECHBREECH (buttocks) or(buttocks) or(lower extremities)(lower extremities)

A.FRANKA.FRANK:: thighs flexed,thighs flexed,

legs extended onlegs extended onanterior surface,anterior surface,buttocks presentingbuttocks presenting

B.FULL OR COMPLETEB.FULL OR COMPLETE::

thighs and legsthighs and legsflexed,buttocks andflexed,buttocks andfeet presentingfeet presenting(squatting)(squatting)

C. FOOTLING orC. FOOTLING or

INCOMPL

ETEINCOMPL

ETE--one or both feet areone or both feet arepresentingpresenting

3.3. SHOULDERSHOULDER(Scapula).CS(Scapula).CS

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Position:Position: relationship of reference point onrelationship of reference point on

fetal presenting partto maternal bony pelvis.fetal presenting partto maternal bony pelvis.

Maternal bony pelvis divided into 4 quadrantsMaternal bony pelvis divided into 4 quadrants

(Rand Lanterior, Rand L posterior)(Rand Lanterior, Rand L posterior)

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2. PASSAGEWAY2. PASSAGEWAY=

shape and measurement of maternal pelvis=

shape and measurement of maternal pelvisand distensibility of birth canal.and distensibility of birth canal.

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False PelvisFalse Pelvis

Shallow upper basinShallow upper basin

of the pelvisof the pelvis

Supports theSupports theenlarging uterusenlarging uterus

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True PelvisTrue Pelvis

Consists of the pelvicConsists of the pelvic

inlet, pelvic cavity,inlet, pelvic cavity,

and pelvic outlet.and pelvic outlet. Influence the conductInfluence the conduct

and progress of laborand progress of labor

and deliveryand delivery

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Engagement: This occurs when the largest

diameter of the presenting part reaches or

passes through the inlet of the true pelvis.

Station: refers to the relationship of the

presenting part to an imaginary line drawn

between the ischial spines of the maternal pelvis

measured in + or - centimeters.

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3. POWER3. POWER-- forces of labor, acting inforces of labor, acting inconcert, to expel the fetus and placenta.concert, to expel the fetus and placenta.

2 Major forces: Involuntary and voluntary2 Major forces: Involuntary and voluntary

INVOLUNTARY:INVOLUNTARY: includes frequency,includes frequency,

regularity, intensity and duration.regularity, intensity and duration.

VOLUNTARY:VOLUNTARY: bearingbearing--down efforts. Thedown efforts. The

contraction of levator ani muscles.contraction of levator ani muscles.

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Uterine contractionUterine contraction

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4. POSITION4. POSITION

Maternal positioning duringMaternal positioning duringlaborlabor

Influence pelvic size andInfluence pelvic size andcontourscontours

Affects pelvic joints, facilitateAffects pelvic joints, facilitatedescent and rotationdescent and rotation

E.g. squattingE.g. squatting enlarges theenlarges thepelvic outlet bypelvic outlet byapproximately 25%approximately 25%

Kneeling removes pressureKneeling removes pressureon the maternal vena cavaon the maternal vena cavaand assists to rotate theand assists to rotate thefetus in the posterior positionfetus in the posterior position((Breslin and Lucas, 2003Breslin and Lucas, 2003))

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5. PSYCHE5. PSYCHE state of mindstate of mindIf the woman feels confident in her ability to cope

and find ways to work with the contractions, thelabor process is enhanced.

A woman who is relaxed, aware, and participatingA woman who is relaxed, aware, and participating

in the birth usually has a shorter, less intense labor.in the birth usually has a shorter, less intense labor.

If the laboring woman becomes fearful or hasintense pain, she may become tense and fight the

contractions.

This situation often becomes a cycle of fear,

tension, and pain that interferes with the progress of

labor.

Approaches to childbirth Lamaze, Bradley

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Thats all for nowThats all for now

Thank you for listening!Thank you for listening!