PROCESS OF NORMAL LABOR

PROCESS OF NORMAL LABOR
CHAPTER 7

Events Before Onset of Labor
nUnknown what actually starts labor
nLightening: “baby drops down”, baby settles in maternal pelvis
nVaginal discharge or bloody show: pink stained mucus
nEnergy spurt or nesting time
nFalse labor: no cervical dilatation
nSpontaneous rupture of membranes or SROM
nCervical changes – effacement & dilatation
nsee Figures 7-1,Table 7-1

Major Variables in the Birth Process: The 4 P’s

nPELVIS--size and shape of the pelvis

nPASSENGER- fetus size and position

nPOWERS-effectiveness of contractions

nPSYCHE-preparation, previous experience


PELVIS
nMust be adequate proportions in order for the fetal head to fit through
nAngles are downward, forward, & upward somewhat like the letter “J”

PASSENGER
nFetal Head – must be able to stand extreme pressure
nFetal Bony Skull – bones thin, very elastic, allows for molding

Fetopelvic Relationship

nTerminology:
•Attitude, fig 7-3
• Lie – relationship of the longitudinal axis of the fetus to the mother, should be parallel, not crosswise
•Presentation, body part lowest in mother’s pelvis, fig 7-4
•Position, more specific description of the relationship of the fetal presenting part to the maternal pelvis, fig 7-4
•Station – fig 7-5, -5 to +5, ischial spines used, hardest to determine during a vaginal exam


POWERS-UTERINE CONTRACTIONS

nInvoluntary
nIntermittent but regular
nExhibit a wavelike pattern in 3 phases:
ØIncrement, building up
ØAcme, peak
ØDecrement, decreasing intensity
nAffected by maternal position
Ø supine, more freq, lower intensity
Ø side lying, less freq, more effective

Assessment of Uterine Contractionsfig 7-6

nFrequency: amount of time between the beginning of one contraction to the beginning of the next
nDuration: time between the onset of the contraction & it’s end
nIntensity: strength of the contraction, rough estimate made by palpation;
Ø mild – easy to indent, like touching tip of nose
Ø moderate – harder to indent but still able to; touching the chin
Ø strong – fundus is very firm & difficult to indent, like touching the forehead
PSYCHE--Psychological and Cultural factors that affect labor
nAnxiety and fear can decrease ability to cope, previous poor experience can effect present experience negatively
nCulture, ethnic background may play a strong role in the way a woman perceives labor and her reaction to it
nMaternal/newborn bonding very important!

MECHANISMS OF LABOR (cardinal movements)

nFigure 7-7
nEngagement and decent
nFlexion
nInternal rotation
nExtension
nCrowning
nExternal rotation
nDelivery of anterior shoulder
nDelivery of posterior shoulder & expulsion

Placental expulsion

n5-30 min after delivery s/s: lengthening of cord--change in shape of uterus-trickle or gush of vaginal blood
nDull- maternal side --Duncan’s mechanism or Dirty Duncan—usually implanted low in uterus
nShiny- fetal side- Schultz’s mechanism or Shiny Schultz—usually implanted high in uterus

FOUR STAGES OF LABOR

n1ST STAGE – begins with the onset of regular contractions until the cervix is fully dilated to 10cm
n2nd STAGE – begins when cervix is fully dilated & ends with birth of the infant
n3rd STAGE – begins with birth of the baby & ends with expulsion of the placenta
n4th STAGE – from placental expulsion to the end of the recovery stage – usually 1-4 hours

Phases of 1st STAGE OF LABOR-

nLATENT PHASE-EARLY STAGE 0-4CM – EARLY, SLOW PART
nACTIVE PHASE-MID PHASE 4CM-7CM – STRONGER CONTRACTIONS
nTRANSITION PHASE-- LAST PART 8CM-10CM-CONTRACTIONS STRONGER, MORE FREQUENT LASTING 60-90 SECS & WOMAN BECOMES IRRITABLE, ANXIOUS, SELF FOCUSED !!!!!


Second Stage of Labor

nExpulsion stage cervix 10 cm
nCoach-- do not hold breath more than 5 secs when pushing
ncrowning of fetal head—seen in external opening of vagina—recedes after contractions
nSecond stage lasts from a few minutes to 2 hours
nepisiotomy- midline or mediolateral
nsupport fetal head and check position of umbilical cord= nuchal cord
nBirth= relief for laboring woman

Third and Fourth Stage

nThird stage-

nBegins with birth to expulsion of placenta lasts up to 30 minutes
nOxytocin (Pitocin) given to keep uterus firm and lessen blood loss after delivery of placenta

nFourth stage-

nRecovery phase after delivery of placenta through first 1-4 hours or until VS stable. 250-500 ml blood loss. CRITICAL--Observe for excessive bleeding! Teach fundal massage.

Physiologic Changes in Laborsee table 7-2

nCardiovascular- increase in b/p, supine hypotension, increased pulse rate
nRespiratory- 02 demand equal to strenous exercise, hyperventilation—encourage to relax between contractions
nRenal--proteinuria, due to muscle breakdown; distended bladder, due to pressure
nGI--peristalsis and absorption decrease--NPO except ice chips, hydration by IV