labor & delivery 6 lecture student version final(1)

8/10/2019 Labor & Delivery 6 Lecture Student Version Final(1)

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Introduction

Uterus: pear-shaped muscle made of 3 layers:Endometriuminner lining - shed during menses.Myometrium - muscle layermiddlePerimetrium - outer layer -extra support to whole

structure.

THEORIES of LABOR:Combination of factors start labor:

Oxytocin & prostaglandin - most importantbiochemical factors in stimulating uterinecontractions.

Estrogen uterus response & progesterone it.


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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; falselabor; DO NOT initiate true labor.

Cervical changes: cervix effaces [thins] & dilates slightly

Baby's head in pelvis pushes against cervix causingrelaxation and effacement.

Burst of Energy: Nesting instinct; cleans house, sets upnursery. 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 toBraxton-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 > distress/infection. Immediate medical attention.

PROM or prolonged ROMintrauterine infection[pathogens reach fetus]


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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 contxsprimip.

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 throughvagina & rectummay have BM.

Positions: Sitting, Side Lying, Standing, Squatting, All Fours,Kneeling.


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Crowning - External viewCardinal Movements - Internal motions


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Third Stage

Delivery of placenta ~ 5 - 30 min.Separation should be automatic [uterus contracts & mombears down]

Dont palpate non-contracted uteruspossible eversion.Maternal vessels still open.

MD/MW presses on contracted uterus. CredesManeuver

Pitocin > 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, & recoveryLasts ~ 1 hr. unless complications arise.

Then pt. transferred to PP unit.


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Nursing Interventions During Labor

Triage - Admit clientto 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 asprescribed .


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Nursing Interventions Cont.

* Provide comfort measures [back rub, ice chips]* Explain equipment & procedures.

* Observe & document time of ROM

Supine hypotensionPosition on side - pressureoff vena cava

Role of coach during active/transitional stages

Assist with pushing during 2ndstage.

Record time of delivery, Apgar score,spontaneous cry, & resuscitative efforts to infant

Monitor infant for extrauterine life adjustment

Encourage family bonding > 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 @ endof 1st stage when contx.s strongest.


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EliminationMonitor UO q 2-4 hr.

Pressure of fetal head reduces bladder tone.Full bladder > inhibits labor.

Catheterize. Remove > delivery.

HydrationIV to hydrate; pt. diaphoretic & NPO x ice chips.

Lactated ringers; good volume expander.


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Assessing Progress of Labor

Dilation: 0

10 cm. [opening cervix] Effacement: 0 100 % [thinning cervix]

Station: Relationship of presenting part to pelvicischial spines-midwayin pelvic cavity.

0 station aka engaged.

-1 to -5 above0

+1 to +5 (outlet) below0

+4/+5: baby's head out.


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Mechanism of Labor: passage of fetus thru birth

canal involves position changescalled: CardinalMovements of Labor: mechanical & spontaneous. 2ndstage

Engagement: presenting part enters midpoint of pelvis @ischial spines.

Descent:downward movement thru pelvic inlet,

thru dilated cervix, reaches posterior vaginalfloor. 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 pelvicstructures)

Extension: top of head delivered & extends as

face & chin are delivered.

External Rotation: head rotates back toprevious lateral position. Rest of body isdelivered.


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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 @ suture lines

Cranial bones move & overlap, allows skull to pass thrubirth canal.

Fontanelles: soft spaces created byjunctures of suturelines - covered by membranes; compress during deliveryto aid in passage of fetus.

Molding of infant head.


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Passenger cont.

Skull widest @ antero-posterior diameter [frontto back] than @ transverse diameter [across].

Antero-posterior diametermeasures differently@ different locations.

Occipitomental diameter- widest - measured from chin toposterior fontanelle = 13.5 cm

Smallest diameter - lower occiput to anterior fontanelle

(suboccipitobregmatic) = 9.5 cm

Complete flexionallows 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 makingdiameter wider (aka military or neutral)

Poor flexion:brow or face presentation; presents

skull diameter too wide making delivery difficult.


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C. Fetal lie: [position of fetus in utero] relationship of longaxis of fetus [spine] to long axis of mother:

1. Longitudinalvertex/breech; vertical inrelation to mom; ~ 99%.

2. Transversehorizontal in relation to mom; < 1 %.

C/S; ^ in grand multipstretched uterine muscles; tryversion.

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

Described 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

tomothers spine. Anterior (A) back of head againstsymphysis pubis & face towards spine. Posterior (P) Backof 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 normalfemale 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 withforceps; 20-25%


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4. Platypelloid < 5 % of women;flattened pelvis; vag. del. difficult


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B. Structure of Pelvis: bones held together byligaments. Supports/protects organs inside.

False Pelvis: Outer - broader. Hip bones.

True Pelvis: Internalnarrower. 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 > C/S.


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PELVIC INLET:

Antero-posterior diameter - front to back ~ 12.5cm. (diagonal conjugate)

True conjugate - actual opening of outlet.

Subtract width of symphysis pubis [1.5 cm] fromdiagonal conjugate. 12.51.5 = 11.0 cm.(complete flexion = 9.5cm diameter)

Transverse diameter [across] ~ 13.5 cm


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MIDPELVIS: narrowest part of pelvis that fetusmust pass through - ischial spines

PELVIC OUTLET: Trouble passing through pelvicopening, pelvis too small or poor fetal attitude.

Soft Tissue: Ligaments, Uterus, cervix, vaginalcanal


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Powers: Uterine contxs: primary force moving fetus thru

maternal pelvis during 1st stage of labor.

Maternal Efforts: woman adds voluntary pushingforce to force of contx.s during 2nd stage oflabor 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, psychhx 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/InternalMonitoring


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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. earlylabor; q 2-3 min. activelabor.

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 regardingcontractions & 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/texcellent coping skills or high pain tolerance


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External Fetal Monitoring

Also Records:Fetal Heart Rate (cardio transducer) FHR

Advantages:Evaluates contractions & FHRProvides written record of both

Disadvantages:May be inaccurate due to maternal/fetalmovements.

Need experienced clinician to read otherwise infocan be misinterpreted.


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Internal MonitoringMore Accurate !

Fetal scalp electrode: wire electrode attached to scalp offetus -monitors FHR accurately & continuously.

Advantages: precise assessment of FHR; not affected byfetal movement.

Disadvantages: lacerations of fetal scalp, mom cantambulate.


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IUPC -intrauterine pressure catheter inserted intouterine cavity to monitor contx.s

precisely/continuously.

Advantages: precise assessment of maternalcontractions. Mom can turn side to side.Measures Intensity: strength of UC internally[30-50mmHg during peak of contx]

Disadvantages: risk of maternal infection, mom cantambulate.


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Fetal Heart Rate

Baseline average fetal heart rate that occursbetween contx.s during 10 min. period.

Normal 110/120 - 160 [accels/decels not counted]

BradycardiaFHR < 110 for 10 minutes; 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 & expectedfinding. Should always be present; appears as jitters.

Clinical Significance- fetal well-being.

Caused bynatural pacemaker ability of FH d/t

effects of sympathetic & parasympatheticnervous system.

Nursing Interventions- cont. monitoring & assesstracing 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 cyclesDrugs (Analgesics, barbiturates, tranquilizers, anesthetics)PrematurityArrhythmiasFetal tachycardia

Preexisting neurological abnormalityCongenital 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 becorrected or delivered ASAP. Experienced RN usually ableto 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 > than 30 sec.

Nadir of decel (lowest point) & peak of contx. (highestpoint) coincide. Mirror image of contx.

Range= lasts as long as contx.; resolves with end ofcontx. Occurs late in labor when head has descended.

Clinical Significance= normal; if it occurs early in laborbefore 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 > end of contx. range - occur 30-40 seconds > contx. starts &

continue > contx. ends clinical significance needs immediate attention;

possible fetal distress. Could be d/t pitocin that iscausing hypertonic uterus.[ too many contx.- notime for recovery]


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-Left lateral position takes pressure

off aorta & vena cava; circulation touterus.

-IV flow rate Circulation

oxygen - face mask [5liters/min].D/C pitocin & document

assist with fetal blood sampling

[measures acidosis in fetus whichsignifies 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 > ROM [less fluid as cushion]

V = C variable decels = cord compression

E = H early decels = head compressionA = 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 offcord

continue monitoring w.EFM

follow hospital protocol: MD will do

amnioinfusion > ROM to supplement amnioticfluid thats left; provides fluid barrier to preventfurther 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 inFHR above normal baseline.

cause- fetal movement; contractions *

shape-FHR rises w. return to baseline; can occur @same time as contx. or independently.

Premie < 32 wks.; 10 bpm rise lasting 10 sec. ok

32 wks. or >, 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 fetalscalp [cervix dilated 3-4 cm]. Clean scalp w. iodine.

Results: 7.25ph > normal7.20 -7.24 preacidotic

< 7.2 + acidosis; indicates hypoxia [O2]

Role of Coach in Labor & Delivery emotional support

physical supporttouch, massage

reduce anxiety

bonding with newborn as a couple

Ob t t i l P d


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Obstetrical Procedures

Episiotomy: incision on perineum toenlarge vaginal outlet. New trend: not doneroutinely. (in 2ndstage)

Types:

Median

vertical incision.Medio-lateral slanted to R/L of perineum; doneif tear anticipated.Advantages: median or midline epis.

medio-lateral prevents tearing towardsrectum. Less chance of laceration.Disadvantages: medio-lateral -longerto heal.


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Forceps: double bladed instrument to assist passage offetus. 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 @ + 2, +3station. Some anesthesia used.

Midforceps & High forceps: not done ^ birth trauma.

Cervical lacerations; Newborns > facial palsy or subduralhematoma; 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 > 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 classicalincision - 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.

Vertical=classical incision. Visible scar; emergencycases; crashC/S. Quick access to baby.

Cesarean Delivery ( C section)


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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

I d ti f L b t t l b G l NSVD


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Induction of Labor:start labor. Goal: NSVD

Without Meds.- NaturalAmniotomy: Artificial ROM; amnio hook; break sac.

Monitor for poss.prolapsed cord.

Continue EFM. Usu.starts contx.s & laborprogresses [@ 3 cm dilation]


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Augmentation:assisting labor thats in progress.Pitocin used.

Contraindications:Maternal: placenta previa; active herpes; structural

abnormalities; previous vertical uterine scar

Fetal: transverse or breech; fetal distress; premie.


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IVF 10 units Pitocin in 1000 ml. RL Start rate @ 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 I&O 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 readinessfor

induction; looks at 5 factors. Score 8 favorable.

Multip can be induced @ 5

Primip can be induced @ 7

Uterus/cervix should respond to induction.

Score < 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 >5 >80 +1, +2


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Cervical Ripening:Artificial softening of cervix beforelabor.

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.

labor & delivery 6 lecture student version final(1)

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