maternity unit 3: Part 1 (ch 16, 17, 19)

what factors affect the babies journey through the birth canal

• size of head

• fetal presentation

• fetal lie

• fetal attitude

• birth canal

what makes up the fetal skull

• 2 parietal bones

• 2 temporal bones

• 1 occipital and 1 frontal

anterior fontanel

• diamond shaped

• 3cm x 2cm (larger)

• closes in 18 months

• where saggital, corornal and frontal sutures meet

posterior fontanel

• triangle shapes

• 1cm x 2cm (smaller)

• closes after 6-8 weeks

• where parietal and occipital bones comes together

molding

• babies heads can be coned shaped

• the sutures allow for overlap of fetal skull bones for more passage through the birth Canal

• normally will go down in 3 days

fetal presentation

• the part of the fetus that enters the pelvic inlet first and leads through the birth canal during labor

• cephalic (vertex/ occiput first), breech (sacrum or feet first), shoulder

fetal lie

• the relation of the fetus spine to the moms spine

• longitudinal - spines align. can be vertex or breech

• transverse - spines are perpendicular to each other (needs c-section)

• oblique - baby is diagonal to mom (usually these go to longitudinal)

fetal attitude

• the relation of fetal body parts to one another (posture)

• we want general flexion - fetal position with chin tucked

• this makes the head the smallest to come out

biparietal diameter

• diameter of head going across the parietal bones

• in general flexion it is 9.25 cm

suboccipitobregmatic diameter

• diameter of head from anterior fontanel to bottom of occipital bone

• 9.5 cm in general flexion

fetal position

• relationship of a reference point on the presenting part to the four quadrants of the mothers pelvis

• 3 letter abbreviations

fetal station

• measure of the degree of descent of the presenting fetus

• -5 to 5

• at 0, (@ ishcal spine) our baby is engaged

• once baby is engaged there is a physiologic ring that keeps baby engaged, not going back in.

what makes up the birth Canal

bony pelvic and soft tissues

• shape of pelvis is ideally determined prenatally

gyenciod pelvis

• 50% - ideal shape

• circle shaped

• straight side walls

• deep curved sacrum

• wide subpubic arch

android pelvis

• heart shaped

• 23%

• convergent sidewalk, narrower diameter

• sacrum slightly curved & terminal portion beaked

• narrow subpucic arch

• increases risk of CPD (cephallopelvic disproportion)

anthropoid pelvis

• oval shaped

• 24%

• straight side walls

• prominent ischial spine with narrow diameter

• sacrum slightly curved

• subpubic arch narrow

• associated with OP position (sunny Side up baby )

platypelloid pelivs

• flat, horizontal oval

• 3%

• straight side walls

• ischial spine blunt and wide diameter

• sacrum slightly curved

• wide subpubic arch

• more likley to have transverse fetal lie

what makes up the soft tissues of the birth canal

• lower uterine segment - become weaker and smoother

• cervix - efaces (thins) and dilates

• pelvic floor muscle

• vagina

• introitus (opening of vagina)

relaxin

• hormone release during brith

• relaxes cartilage and connective tissue of symphimis pubis and sacroiliac joint

• shifts expand and widens

primary powers

• involuntary contractions

• measured in frequency, duration and intensity

• timed either beginning to beginning or peak to peak

• responsible for efacement and dilation

efacement + dilation in 1st time mom vs subsequent

• 1st timer - can happen 2wks before dilation with lightening

• subsequent - can happen right before labor

Ferguson reflex

• once baby is hits the pelvic floor, stretch receptors signal the brain to release oxytocin

• this gives you the urge to push

• do not let mom push until she is 10cm dilated to avoid cervical tears

secondary powers

• bearing down or vasalva manuever

• pushing while holding breath

• raises moms BP and CO, decreases placental perfusion, causing fetal hypoxia and lowers fetal heart rate

laboring down

• once mom is in 2nd stage (100% effaced and and 10cm dilated)

• but mom does not push, we allow the baby to move down passively to conserve moms energy

frequent position chnages helps with

• decreasing fatigue

• increasing comfort and circulation

• helps baby fully engage

signs preceeding labor (8)

• lightening + urinary frequency due to pressure

• bloody show (red or brown tinged mucus plug)

• energy surge (aka nesting)

• 1-3.5 lb weight loss

• stronger Braxton hicks contractions

• backache

• nausea and diarrhea (oxytocin contracts smooth muscle)

• cervical ripening

why is ROM not a sign of labor

• even after Rom, baby may not be ready to come

• some babies membranes stay intact all through labor (encaul birth)

• after 24 hours, there is r/o infection bc the barrier to protect baby is broken

1st stage of labor

• begins once mom has regular uterine contractions to when cervix is 10cm dilated and is 100% effaced

• longest phase

• latent phase - (0-5cm dilated) more effacement & milder contractions

• active phase - (6-10 cm dilated) more dilation & stronger contractions & baby descends faster

2nd stage of labor

• from 10cm dilation to when baby is born

• latent - passive “laboring down“

• active - Ferguson reflex (pushing)

third stage

• placenta stage

• from after the baby is born to when the placenta is delivered

• 10-15 minutes after baby comes out, should not take longer than 30 minutes

• apparent lengthening of umbilical cord

• sudden gush of dark blood and feeling of vaginal fullness

• usually will take 3-4 mild contractions

fourth stage

• from when placenta is delivered until 2 hours after birth (usually)

• initial recovery period

• watch mom closely - high r/o hemorrhage, HR, BP, fundal checks q15 min

what do we watch for in baby during labor

• fetal HR

• fetal circulation - determined by moms position

• fetal respiration

fetal HR

• monitor FHR - reliable and predictable information about fetal perfusion

• must be watched closely

• perfusion drops while uterus contracts, usually is not a problem unless contractions are prolonged

• 110-160 bpm

fetal respiration

• as baby is squeezed through birth canal, fluid in lungs clear out

• O₂ drops slightly and CO₂ raises to initiate the biological drive to take the first breath and diaphragm retracts

mom cardiovascular changes in labor

• CO increases by 12-31% in first stage, and more in 2nd stage

• HR increases slightly in stage 1 and 2

• BP increases during contractions

• increased WBCs

• decreased blood glucose

mom respiratory changes in labor

increased rate

mom renal chnages in labor

• protein in urine is normal due to increased metabolism and breakdown of muscle

• dysuria

• moms bladder should be fully emptied, usually she is catheterized

mom integumentary chnages in labor

• higher temp

• lacerations or episiotomy

mom musculoskeletal changes in labor

• backaches

• joint aches

• leg cramps

• thigh pain

mom nuero changes in labor

• increases endorphins provide pain relief and mild analgesia in between contractions

mom GI changes in labor

• slowed motility

• absorption of solid food decreases

• nausea and vomiting

• mom may be NPO if at risk for C-section

mom endocrine changes in labor

• increased estrogen , oxytocin and prostaglandins

• decreased progesterone

• high metabolism and fatigue

7 normal mechanisms of labor

• engagement

• descent

• flexion

• internal rotation

• extension

• external rotation

• expulsion

Every Dumb Fool In Egypt EatsRaw Eggs

• Engagement

• Descent

• Flexion

• Internal rotation

• Extension

• ExternalRotation

• Expulsion

1. engagement

The fetal head passes into the pelvic inlet (0 station)

2. descent

The fetus moves downward through the pelvis, driven by contractions

3. flexion

The chin moves to the chest after hitting resistance to present the smallest head diameter

4. internal rotation

The head rotates 45 degrees to face the mother’s back to fit the pelvis.

5. extension

The head passes under the pubic bone and lifts up to emerge

• head is delivered!

6. external rotation/ resistution

The head realigns with the shoulders, turning to one side.

• anterior shoulder goes first, then posterior shoulder

7. expulsion

The body is out

• end of 2nd stage

visceral pain

• comes from lower uterine segment distending

• can be referred to abd wall, glutes, thighs, etc.

somatic pain

• only @ end of 1st stage/ 2nd stage

• localized, sharp pain

perception of pain can be influenced by

• culture

• age

• past experiences of pain/ labor

• support system

physiologic reactions of pain

• high BP, HR, RR, fatigue

• decreases placental perfusion and uterine slowing

• releases catecholamines - slows labor process

sensory / emotional reactions to pain

• anxiety, crying, groaning, clenching

pt with hx of sexual abuse

• as little people interacting with her as possible

• same person doing internal exams

• risk for retraumatization

Effleurage

• light stroking, usually of the abdomen, in rhythm with breathing during contractions.

Counterpressure

• steady pressure applied by a support person to the sacral area with a firm object (e.g., tennis ball) or the fist or heel of the hand.

• Pressure can also be applied to both hips (double hip squeeze) or to the knees

when applying heat

• it needs an order

• it is a vasodilator and contribute to hemorrhage

• in postpartum, not on abdomen or back

cutaneous stimulation of pain relief

• countermeasure

• effleurage

• therapeutic touch

• walking, rocking, changing position

• heat/ cold

• TENS

• acupressure

• water therapy

• intradermal water block - injection of small amounts of sterile water into four locations on the lower back to relieve lower back pain

sensory stimulation strategies of pain relief

• aroma therapy

• breathing techniques

• music

• imagery

• focal point

cognitive strategies of pain relief

• birth education

• hypnosis

sedatives

• relieve anxiety and induce sleep, but they do not provide analgesia.

• Barbiturates, phenothiazines, and benzodiazepines

• used for women in a prolonged latent phase of labor (stage 1)

anesthesia

• encompasses analgesia, amnesia, relaxation, and reflex activity

• interrupts the nerve impulses to the brain.

analgesia

• the alleviation of the sensation of pain or the raising of the threshold for pain perception without loss of consciousness.

systemic analgesia

• opioids readily cross placenta

• analgesic effect in labor is limited

• can have profound effect on newborns, may need narcan

nerve block analgesia

• produce temporary sensory blockade and various degrees of motor blockade over a specific region of the body

• mom can still feel contractions

• usually the -caines (lidocaine, etc.)

allergic reaction to nerve block (what is looks like and what to do )

• hypoventilation & hypotension - reduces FHR

• put mom sidelying with wedge under 1 hip and legs elevated

• give vasopressor and oxygen

• monitor maternal vitals and FHR q5min, stay with mom, notify MD

Local Perineal Infiltration Anesthesia

• for episiotomy or laceration

• given before the cut/ repair of laceration

• lidocaine with epi to localize and intensify effect & prevent excessive bleeding

Pudendal Nerve Block

• administered late in the second stage of labor

• useful if an episiotomy is to be performed or if forceps or a vacuum extractor are to be used to facilitate birth

• also administered during the third stage of labor if an episiotomy or lacerations must be repaired

• needs up to 20 minutes to work

spinal

• injected into subarachnoid space

• C-section - numbness from nipples to feet

• vaginal birth - numbness from hips to feet

• monitor mom’s BP and FHR closely during procedure

epidural

• most effective pain relief for labor

• does not remove contraction feeling , mom can still have sensation to push

• monitor mom’s BP and FHR closely during procedure

post-dural puncture headache

• from leakage or displacement of CSF

• lay mom down on back (after delivery, no supine hypotension)

• give Tylenol

• give caffeine like coke

• epidural blood patch - anesthesia take moms blood and fills the displaced area

Side Effects of Neuraxial Anesthesia

• Hypotension

• Local anesthetic toxicity

• Fever

• Urinary retention

• Pruritus (itching)

• Limited movement

• Longer second-stage labor

• Increased use of oxytocin

• Increased likelihood of forceps- or vacuum-assisted birth

• High or total spinal anesthesia

Local anesthetic toxicity

• Light-headedness

• Dizziness

• Tinnitus (ringing in the ears)

• Metallic taste

• Numbness of the tongue and mouth

• Bizarre behavior

• Slurred speech

• Convulsions

• Loss of consciousness

nitrous oxide

• laughing gas

• used in 1st and 2nd stage of labor

• PCA mask

combined spinal-epidural (CSE) analgesia

• “walking epidural” but most women don’t walk bc of sedation and fatigue

• block pain transmission without compromising motor function

contrandications to spinal block/ epidural

• Harrington (scoliosis rods)

• high risk uterine issue

• Active or anticipated serious maternal hemorrhage

• Maternal hypotension

• Coagulopathy

• Infection at the needle insertion site

• Increased intracranial pressure

  • Allergy to the anesthetic drug.

  • Maternal refusal or inability to cooperate.

  • Some types of maternal cardiac conditions.

general anesthesia

• rarely used for uncomplicated vaginal births. It is used for only about 6% of cesarean births

• only used when spinal cant be used (look at contraindications)

• risk for aspiration of gastric contents, must be NPO or given clear oral antacid to neutralize stomach contents

• baby must be delivered ASAP due to r/o neonatal narcosis

determining wether a woman is in true labor

• ask about contraction

• asses cervical effacement and dilation

EMTALA

• any hospital (besides private) must take any woman in true labor regardless of insurance. location etc.

• a woman is to be considered to be in true labor until qualified provider determines that she is not

signs of true labor

• contractions are regular, longer lasting, occurring closer together

• more intense with walking

• felt in low back but radiates to lower abd

• continue despite use of comfort measures

signs of false labor

• irregular contractions

• stop with position change or walking

• felt in upper abdomen

• can usually be stopped using comfort measures

admission data includes

• prenatal data

• SROM - color? when did it happen?

• green - meconium , respiratory issue

• should have no odor

• psychosocial factors - hx of abuse?

• stress in labor - cultural / language factors

physical exam

• head to toe + vitals

• Leopold manuever - checking fetal position with abdominal palpation

• assess FHR

assessing contractions

• frequency

• intensity - mild (feels like nose), moderate( feels like chin) or strong(feels like forehead) (feeling her abdomen)

• duration

• resting tone - needed for fetal perfusion

vaginal exam

• reveals wether she is in true labor (effacement and dilation, ROM and fetal descent )

• not done during contraction - stressful and uncomfortable

Lab tests

• urinalysis

• blood tests (CBC, HIV/ Hepatitis if needed, & blood typing)

• GBS if unknown

assessing nuchal cord

• stop baby at perineum and check where the cord is

• may have to be reduced if around baby’s neck or cut completely

• assess any knots (reduced perfusion)

lotus birth

• umbilical cord is never cut, it dries up and falls off

• risk of hyperbilirubinemia - jaundice

• usually not done in hospital, cord is kept for max of 3 minutes

first degree tear

laceration that extends through the skin and vaginal mucous membrane but not the
underlying fascia and muscle

2nd degree tear

laceration that extends through the fascia and muscles of the perineal body, but
not the anal sphincter

third degree tear

laceration that involves the external anal sphincter

4th degree tear

laceration that extends completely through the rectal mucosa, disrupting both the external and internal anal sphincters

episiotomy

• either median or mediolateral

• less common in recent years

caring for episiotomy

• ice

• topicals: witch hazel pads & hemorrhoid creams

• reduces swelling, soothes, keeps skin cool and moist

• peri bottles with warm water

placental examination

• should be intact

• if pieces of placenta remain in mom it can cause hemmorahge

Post Anesthesia recovery score components

• activity

• respirations

• BP

• LOC

• skin color

removal of epidural catheter

• Anesthesia or a qualified/ educated nurse

• catheter must be intact