Lecture 3 LABOR & DELIVERY CHAP. 18,19, 20

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LABOR DELIVERY
Lecture 6
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Introduction Uterus pear-shaped muscle made of
3 layers Endometrium inner lining - shed
during menses. Myometrium - muscle layer middle
Perimetrium - outer layer -extra support to
whole structure. THEORIES of LABOR
Combination of factors start labor Oxytocin
prostaglandin - most important biochemical
factors in stimulating uterine contractions.
Estrogen ? uterus response progesterone ?
it.
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• THEORIES
• Oxytocin Stimulation Term uterus sensitive to
  oxytocin ? d/t pressure exerted on cervix by
  fetus.
• Progesterone Withdrawl ? progesterone by fetus
  ? prostaglandins in chorioamnion results in ?
  uterine contxs.
• Estrogen Stimulation ? progesterone allows
  estrogen to ? contractile response of uterus.
• Fetal Cortisol Changes biochemistry of fetal
  membrane ? progesterone ? prostaglandin in
  placenta.
• Distention uterine muscles stretch causing ?
  prostaglandin.
• Amniotic membranes (sac) makes arachidonic Acid ?
  Prostaglandin - uterine contractility.

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• Premonitory signs of labor weeks before real
  labor
• AKA False Labor
• Lightening Fetus settles into pelvic cavity.
• Braxton-Hicks Irregular intermittent
  contractions false labor DO NOT initiate
  true labor.
• Cervical changes cervix effaces thins
  dilates slightly
• Baby's head in pelvis pushes against cervix
  causing relaxation and effacement.
• Burst of Energy Nesting instinct cleans house,
  sets up nursery. ? epinephrine resulting from ?
  progesterone
• Cervix in posterior position.

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• Signs True Labor closer to time of delivery
• Uterine Contractions regular frequent compared
  to Braxton-Hicks. Stronger w. time.
• Bloody Show pink tinged secretions d/t softening
  cervix.(aka mucous plug)
• Rupture of Membranes (ROM) Labor in 24 hrs.
  Multiparas sooner. Big gush or slow trickle.
• Clear/odorless. Green/brown, danger sign
• Meconium aspiration gt distress/infection.
• Immediate medical attention.
• PROM or prolonged ROM intrauterine infection
  pathogens reach fetus

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Difference Between True False Labor True
Labor A. regular contxs
B. discomfort begins in back spreads to
abdomen. C. progressive cervical
dilation/effacement D. Interval between contx.s
become shorter E. intensity of contx.s ? with
ambulation F. contx.s ? in duration
intensity False Labor A. irregular contx.s B.
discomfort localized in abdomen C. no change D.
No change E. Ambulation has no effect F. No change
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STAGES of LABOR
4 in All !

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First Stage Onset of
true labor to complete dilation 10 cm. 6-18
hrs. primapara 2-10 hrs. multipara. Cervix
becomes more anterior. 3 phases Latent, Active,
Transitional. Latent Dilation 0-3 cms.
Contx.s mild/irregular. Active 4-7 cms.
Contx.s 5-8 min. apart. Lasts 45-60 sec
moderate - strong intensity. Transitional
Dilation 8-10 cms. Contx.s 1-2 min. apart
60 90 sec. strong intensity. No pushing til
fully dilated.
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Second Stage Birthing of
Baby Delivery of infant up to 1 hr. or 20
contxs primip. 20 min. or 10 contxs in
multip. Can last up to 3 hrs.! Cardinal movements
occur here. Most difficult uncomfortable part
of labor. Crowning occurs at 4 -5
station. Strong urge to push bear down as
infant passes through vagina rectum may have
BM. Positions Sitting, Side Lying, Standing,
Squatting, All Fours, Kneeling.
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• Crowning - External view
• Cardinal Movements - Internal motions

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• Third Stage
• Delivery of placenta 5 - 30 min.
• Separation should be automatic uterus contracts
  mom bears down
• Dont palpate non-contracted uterus possible
  eversion. Maternal vessels still open.
• MD/MW presses on contracted uterus. Credes
  Maneuver
• Pitocin gt placenta delivered to avoid retained
  placenta.
• If no spontaneous delivery of placenta, manually
  removed.
• Antibiotics

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Fourth Stage Placenta out
mother recovers in LDR Labor,
delivery, recovery Lasts 1 hr. unless
complications arise. Then pt. transferred
to PP unit.
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• Nursing Interventions During Labor
• Triage - Admit client to birthing area
• MD determines true labor
• Emotional support encourage rest
• Progress of labor
• Monitor/document contractions FHR q 15 min.
• Monitor/document maternal VS q 1 - 4 hr
• Assess pain provide pain relief as prescribed

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Nursing Interventions Cont.

• Provide comfort measures back rub, ice chips
• Explain equipment procedures.
• Observe document time of ROM
• Supine hypotension Position on side - pressure
  off vena cava
• Role of coach during active/transitional stages
• Assist with pushing during 2nd stage.
• Record time of delivery, Apgar score, spontaneous
  cry, resuscitative efforts to infant
• Monitor infant for extrauterine life adjustment
• Encourage family bonding gt delivery

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• Breathing Techniques
• Slow chest 6-12 easy breaths/min. Used in
  early labor.
• Combination quicker, lighter breaths
• Used during active labor one slow breath in
  beginning quicker breaths to follow.
• Pant-Blow 3 - 4 quick breaths, with forceful
  exhalation. Used _at_ end of 1st stage when contx.s
  strongest.

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Elimination Monitor
UO q 2-4 hr. Pressure of fetal head reduces
bladder tone. Full bladder gt inhibits labor.
Catheterize. Remove gt delivery.
Hydration IV to hydrate pt.
diaphoretic NPO x ice chips. Lactated
ringers good volume expander.

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• Assessing Progress of Labor
• Dilation 010 cm. opening cervix
• Effacement 0 100 thinning cervix
• Station Relationship of presenting part to
  pelvic ischial spines -midway in pelvic cavity.
• 0 station aka engaged.
• -1 to -5 above 0
• 1 to 5 (outlet) below 0
• 4/5 baby's head out.

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Mechanism of Labor passage of fetus thru birth
canal involves position changes called Cardinal
Movements of Labor mechanical spontaneous.
2nd stage Engagement presenting part enters
midpoint of pelvis _at_ ischial spines. Descent
downward movement thru pelvic inlet, thru
dilated cervix, reaches posterior vaginal floor.
Mom feels like pushing. Widest part head passed
thru pelvis. active forces of labor. Flexion
pressure from pelvic floor causes head to flex
towards chest chin touches chest.
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Internal Rotation occiput back of head in
diagonal position rotates towards face down
position. / to ? (occurs as body parts press
on bony pelvic structures) Extension top of head
delivered extends as face chin are
delivered. External Rotation head rotates back
to previous lateral position. Rest of body is
delivered.
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• Factors affecting labor process
• 4 Ps Powers of Labor
• Passenger
• Passageway
• Powers
• psyche

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Passenger infant Fetal head widest part of
body most difficult to pass thru vaginal canal
passage depends on bones, sutures,
fontanelles. Cranium - 8 bones meet _at_ suture
lines Cranial bones move overlap, allows skull
to pass thru birth canal. Fontanelles soft
spaces created by junctures of suture lines -
covered by membranes compress during delivery to
aid in passage of fetus. Molding of infant
head.
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Passenger cont.

• Skull widest _at_ antero-posterior diameter front
  to back than _at_ transverse diameter across.
• Antero-posterior diameter measures differently _at_
  different locations.
• Occipitomental diameter- widest - measured from
  chin to posterior fontanelle 13.5 cm
• Smallest diameter - lower occiput to anterior
  fontanelle (suboccipitobregmatic) 9.5 cm
• Complete flexion allows smallest diameter of
  fetal skull to enter pelvis most easily.

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B. Fetal Attitude degree of flexion of fetal
head chin touches sternum. Complete flexion
allows smallest diameter of skull to pass thru
pelvic cavity. Best position! Moderate flexion
head less flexed making diameter wider (aka
military or neutral) Poor flexion brow or face
presentation presents skull diameter too wide
making delivery difficult.
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Friedmans Curve

• Friedman's Curve describes progress of two
  variables over time dilation of cervix and
  descent of baby.
• Labor is dysfunctional when cervix stops
  dilating or fetal descent stops or both.
• Possible diagnosis of "failure to progress"
• C-section indicated.
• Maybe due to CPD (cephalo pelvic disproportion or
  epidural anesthesia (can slow labor).

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C. Fetal lie position of fetus in utero
relationship of long axis of fetus spine to
long axis of mother 1. Longitudinal
vertex/breech vertical in relation to mom
99. 2. Transverse horizontal in relation to
mom lt 1 . C/S in grand multip
stretched uterine muscles try version. 3.
Oblique - diagonal D. Fetal presentation part
of fetal head enters pelvis 1. Cephalic
95.5 2. Breech 3.5 3. Face 0.3 4. Shoulder
0.4 transverse lie
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E. Fetal position occiput is landmark Describe
d in 3 letters 1st presenting part in
relation to mothers R or L. Middle presenting
part occiput, mentum, sacrum Last landmark is
anterior, posterior, transverse in relation to
mothers spine. Anterior (A) back of head
against symphysis pubis face towards spine.
Posterior (P) Back of head mothers spine
painful contxs. Transverse (T) fetus
sideways. Common positions in vertex
presentations LOA, ROT, ROP, ROA, LOT, LOP.
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• Passageway
• Refers to fetus passing thru uterus, cervix,
  vaginal
• canal. Single most important determinant to
  mechanism
• of labor.
• A. 4 Types of pelvis
• 1. Gynecoid 50 of women rounded, oval shape
  easy vaginal delivery considered normal female
  pelvis

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• 2. Android 20 of women vaginal delivery
  difficult prob. C/S true male pelvis
• 3. Anthropoid oval assisted vaginal birth
  usually with forceps 20-25

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• 4. Platypelloid lt 5 of women flattened
  pelvis vag. del. difficult

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• B. Structure of Pelvis bones held together by
  ligaments. Supports/protects organs inside.
• False Pelvis Outer - broader. Hip bones.
• True Pelvis Internal narrower. Holds bladder,
  rectum, reprod. Organs.
• True pelvis - 3 parts - inlet, midpelvis,
  outlet.
• Most important in childbirth
• If pelvis too small, home birth not done.
• CPD - cephalopelvic disproportion gt C/S.

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PELVIC INLET Antero-posterior diameter -
front to back 12.5 cm. (diagonal conjugate)
True conjugate - actual opening of outlet.
Subtract width of symphysis pubis 1.5 cm from
diagonal conjugate. 12.5 1.5 11.0
cm. (complete flexion 9.5cm diameter)
Transverse diameter across 13.5 cm
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MIDPELVIS narrowest part of pelvis that fetus
must pass through - ischial spines PELVIC
OUTLET Trouble passing through pelvic opening,
pelvis too small or poor fetal attitude.

Soft Tissue Ligaments, Uterus, cervix, vaginal
canal
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• Powers
• Uterine contxs primary force moving fetus thru
  maternal pelvis during 1st stage of labor.
• Maternal Efforts woman adds voluntary pushing
  force to force of contx.s during 2nd stage of
  labor to propel fetus thru pelvis.

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• Psyche
• Psychologic Response to birth process
• Prepared for childbirth - Childbirth
  classes-Prenatal care.
• Previous childbirth experience - Complicated?
• Support from significant other - Separated?
  Marital strain? FOB involved? Abuse?
• Emotional status - anxious/depressed, drug use,
  psych hx
• Culture - background may influence response to
  pain. Some moan, some stoic, some verbally
  expressive.
• Fear/anxiety exacerbate pain ? uterine
  dysfunction ineffectual labor posttraumatic
  stress disorder

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Maternal/Fetal Evaluation
During Labor With
Electronic
External/Internal Monitoring

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• EFM electronic fetal monitoring
• Measures
• Fetal Heart Rate (FHR) and Uterine Contractions
  (UC)
• External Toco (UC) and Cardio (FHR)
• Toco transducer uses graph paper 60 sec
  intervals
• UC assessed for intensity, length, frequency.
• Abdominal palpation. Uterus hard then soft.

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As contractions intensify, labor
progresses. Vaginal Exam - dilation, effacement,
station, presentation.
3 Phases of UC a. increment ? b. acme
peak c. decrement
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Assessment Intermittent - 20 minute tracing
standard. Continuous - for active labor or with
complications. Duration beg. of contx. to end
of same contx. Lasts 30 sec. early to 60
sec. active. Frequency beg. of one contx. to
beg. of next. q 5 -30 min. early labor q 2-3
min. active labor. Resting Tone period of
uterine rest bet. contx.s. Measure by
palpation internally measures 10 mmHg.
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• Be Careful Not To.
• Rely on verbal clues from mother regarding
  contractions labor progress.
• Misleading, giving false impression of good labor
  pattern.
• Contractions may be more or less intense than
  what pt. reports.
• RN may miss forceful contractions d/t excellent
  coping skills or high pain tolerance

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External
Fetal Monitoring Also Records Fetal Heart
Rate (cardio transducer) FHR Advantages
Evaluates contractions FHR Provides written
record of both Disadvantages May be inaccurate
due to maternal/fetal movements. Need experienced
clinician to read otherwise info can be
misinterpreted.
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Internal Monitoring
More Accurate ! Fetal scalp
electrode wire electrode attached to scalp of
fetus -monitors FHR accurately continuously.
Advantages precise assessment of FHR not
affected by fetal movement. Disadvantages
lacerations of fetal scalp, mom cant ambulate.

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IUPC -intrauterine pressure catheter
inserted into uterine cavity to monitor
contx.s precisely/continuously.
Advantages precise assessment of maternal
contractions. Mom can turn side to side.
Measures Intensity strength of UC internally
30-50mmHg during peak of contx
Disadvantages ? risk of maternal infection, mom
cant ambulate.
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• Fetal Heart Rate
• Baseline average fetal heart rate that occurs
  between contx.s during 10 min. period.
• Normal 110/120 - 160 accels/decels not counted
• Bradycardia FHR lt 110 for 10 minutes lt100bpm
  sign of fetal hypoxia danger sign.
• Seen with prolapsed cord
• Tachycardia FHR gt 160 for 10 minutes.
• assoc. with maternal temp. and infection such
  as
• chorioamnionitis.

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• Variability FHR aka Baseline Variability
• Fluctuations in FHR. Normal expected finding.
  Should always be present appears as jitters.
• Clinical Significance- fetal well-being.
• Caused by natural pacemaker ability of FH d/t
  effects of sympathetic parasympathetic nervous
  system.
• Nursing Interventions- cont. monitoring assess
  tracing q 15 min. Should show 6-25 bpm
  fluctuations within one min. period.
• 120 ? 135 reassuring

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Main Causes of decreased variability
include Hypoxemia/acidosis (due to fetal
distress) Fetal sleep cycles Drugs (Analgesics,
barbiturates, tranquilizers, anesthetics) Prematur
ity Arrhythmias Fetal tachycardia Preexisting
neurological abnormality Congenital anomalies
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• Decreased variability of FHR
• Nursing Interventions
• accoustic stimulation to wake fetus
• Narcan
• Amnioinfusion - decreases cord comp
  dilutes mec.
• Left/right lateral position or
  knee-chest notify MD
• fetal scalp pH, possible emergency
  C/S IVF, O2
• Flat tracing or minimal aka non-reactive
  tracing pencil mark pattern indicates
  fetal distress must be corrected or delivered
  ASAP. Experienced RN usually able to determine
  reason for non-reactive tracing.

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How Do Uterine Contractions Affect Fetal Heart
Rate? Uterine contractions can affect fetal
heart rate by increasing or decreasing that rate
in association with any given contraction. The
three primary mechanisms by which uterine
contractions can cause a decrease in fetal heart
rate are compression of Fetal head
compression Umbilical cord compression Uterine
myometrial vessel compression
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• Decelerations decreases in FHR.
• Early deceleration of FHR- periodic ? in FHR
• Cause head compression during contx.s
• Shape onset of decel to peak gt than 30 sec.
• Nadir of decel (lowest point) peak of contx.
  (highest point) coincide. Mirror image of contx.
• Range lasts as long as contx. resolves with end
  of contx. Occurs late in labor when head has
  descended.
• Clinical Significance normal if it occurs early
  in labor before head fully descends, may be
  indication for cephalo-pelvic disproportion CPD.

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• Late deceleration of FHR
• Cause uteroplacental insufficiency or ? blood
  flow thru uterus during contx.s
• Shape nadir of decel. occurs gt end of contx.
• range - occur 30-40 seconds gt contx. starts
  continue gt contx. ends
• clinical significance needs immediate attention
  possible fetal distress. Could be d/t pitocin
  that is causing hypertonic uterus. too many
  contx.- no time for recovery

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• Nursing Interventions
• -Left lateral position takes
  pressure
• off aorta vena cava
  ?circulation to
• uterus.
• -? IV flow rate ? Circulation
• oxygen - face mask 5liters/min.
• D/C pitocin document
• assist with fetal blood sampling
• measures acidosis in fetus which signifies
  hypoxia
• Prepare for emergency C/S if decels. persist

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Variable deceleration of FHR Cause compressed
umbilical cord Shape U or V shaped waves in
FHR Range no pattern occur in relation to
contx.s Clinical Significance fetus lying on
cord could be dangerous if persist. Occurs
more gt ROM less fluid as cushion V C
variable decels cord compression E H
early decels head compression A O
accelerations OK L P late decels
Placental insufficiency Bradycardia R/O
prolapsed cord emergency!
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• Nursing Interventions
• oxygen via face mask IV fluids
• change maternal position take pressure off cord
• continue monitoring w.EFM
• follow hospital protocol MD will do
  amnioinfusion gt ROM to supplement amniotic fluid
  thats left provides fluid barrier to prevent
  further cord compression.
• Sterile, warm 500 ml NS/RL inserted into uterus
• EFM observed for improved FHR pattern.

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• 4. Accelerations of FHR temporary abrupt
  increase in FHR above normal baseline.
• cause- fetal movement contractions
• shape-FHR rises w. return to baseline can occur
  _at_ same time as contx. or independently.
• Premie lt 32 wks. 10 bpm rise lasting 10 sec. ok
• 32 wks. or gt, 15 bpm rise baseline lasting 15
  sec. ok
• ex. 135 ? to 150s for 30 seconds.
• clinical significance normal signifies fetal
  well-being. FHR meeting demands of labor process
  well.

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• Fetal Blood Sampling- assesses fetal hypoxia
  from fetal scalp cervix dilated 3-4 cm. Clean
  scalp w. iodine.
• Results 7.25ph gt normal
• 7.20 -7.24 preacidotic
• lt 7.2 acidosis indicates hypoxia ? O2
• Role of Coach in Labor Delivery
• emotional support
• physical support touch, massage
• reduce anxiety
• bonding with newborn as a couple

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Obstetrical Procedures Episiotomy incision on
perineum to enlarge vaginal outlet. New
trend not done routinely. (in 2nd stage) Types
Median vertical incision. Medio-lateral
slanted to R/L of perineum done if tear
anticipated. Advantages median or midline
epis. medio-lateral prevents tearing towards
rectum. Less chance of laceration.
Disadvantages medio-lateral -longer to heal.
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• Forceps double bladed instrument to assist
  passage of fetus. Not routinely done today.
• When 2nd stage labor has stopped d/t epidural
• Infant in abnormal position posterior position
  in birth canal macrosomia.
• Outlet Low forcep delivery fetal head _at_ 2,
  3
• station. Some anesthesia used.
• Midforceps High forceps not done birth
  trauma.
• Cervical lacerations Newborns gt facial palsy or
  subdural hematoma forcep marks on face.

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• Vacuum Assisted Delivery
• disk shaped cup placed on scalp vacuum
• pressure applied pull will deliver infant.
• No anesthesia - fewer cervical lacerations.
• Not done in preterm infants d/t soft skull.
• Used in C/S.
• Not used gt scalp pH done risk for hematoma
  vacuum pressure.
• Can cause caput for 1 wk. Used w.macrosomia.

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• VBAC vaginal birth after cesarean
• OK after low abd. incision Not after classical
  incision - risk for uterine rupture.
• New Trend not routinely done anymore. Pros
  cons
• 1st baby breech, fetal distress, pre-eclampsia
• Should space deliveries 18 mos. apart. to
  prevent rupture

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Types of Uterine Incisions Low transverse
Pfannenstiel bikini cut. Most desired
less visible. Right above pubic bone.
Verticalclassical incision. Visible scar
emergency cases crash C/S. Quick access to
baby.
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• Cesarean Delivery ( C-section)
• Major Indications for C/S
• Active genital herpes or overgrowth of genital
  warts
• HIV infection
• CPD (cephalopelvic disproportion)
• Severe HTN (toxemia)
• Failure to progress with labor
• Previous C/S with classical incision (vertical)
• Placenta previa
• Placental abruption separation of placenta from
  uterus
• Cord Prolapse Macrosomia large fetus
• Breech positions Fetal Distress Transverse
  fetal lie

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Induction of Labor start labor. Goal
NSVD Without Meds.- Natural Amniotomy
Artificial ROM amnio hook break sac. Monitor
for poss.prolapsed cord. Continue EFM.
Usu.starts contx.s labor progresses _at_ 3 cm
dilation
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With Meds. Pitocin drug of choice. 1/3 rd
deliveries _at_ term in US done by induction.
Reason Life in uterus no longer beneficial
Fetal maturity 39 wks, post dates 41-42 wks.
Cervical Readiness- ripe 3 cm. dilated.
Longitudinal lie presenting part engaged
Fetal Demise, Arrest of Labor Induction -
give Pitocin IVPB, slowly as labor
progresses shut off if contxs too strong. Need
MD order.
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Augmentation assisting labor thats in
progress. Pitocin used. Contraindications Mater
nal placenta previa active herpes structural
abnormalities previous vertical uterine
scar Fetal transverse or breech fetal distress
premie.
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• Nursing Interventions
• IVF 10 units Pitocin in 1000 ml. RL
• Start rate _at_ 1 milliunit/min - pump
• Gradually ? to establish effective contx. pattern
• Monitor UC for frequency, rate, intensity
• Monitor FHR for signs of fetal distress
• Maternal BP, pulse, temp
• IO
• Notify MD of progress
• Chart q 15 min on graph
• Prepare for delivery radiant warmer, O2,
  suctioning,
• Hyper-stimulation of uterus shut off pitocin as
  per MD.

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• Bishops score determines cervical readiness for
  
• induction looks at 5 factors. Score 8
  favorable.
• Multip can be induced _at_ 5
• Primip can be induced _at_ 7
• Uterus/cervix should respond to induction.
• Score lt 5 low probability of success. Ripen
  cervix 1st.

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Bishop Scoring System - evaluates cervical
readiness for induction. 5 elements
measured Score Cervical Cervical
Station Cervical Position
dilation effacement
consistency _______cm.___________________________
____________ 0 closed 0-30
-3 firm posterior 1
1-2 40-50 -2 medium
mid 2 3-4 60-70 -1,
0 soft anterior 3 gt5
gt80 1, 2
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Cervical Ripening Artificial softening
of cervix before labor.
Prostaglandin gel 0.5mg.or dinoprostone
10mg.cervidil 2-3 times q 12 for max.
of 24 hrs. Done if cervix
unripe or thick undilated.