normal labor & delivery Flashcards
define “lie”
Relationship of long axis of fetus to that of mother
midpregnancy lie is _______ and later on becomes _______
transverse, more vertical
define “ presentation”
That part of infant presenting in maternal pelvis
3 types of “presentation”
Head = cephalic or vertex Buttocks = breech Feet = footling breech
breech: complete, incomplete and frank
complete- legs crossed in front
incomplete- one leg extended up
frank- both legs extended up
define “denominator”
Reference point on fetus to determine position (what you would feel first)
what is the denominator on the skull, face, butt, shoulder ?
On the skull it is the occiput (back of head)
On face it is chin or mentum
On the butt it is the sacrum
On the shoulder it is the acromion
what cephalic presentation is it when the head is cocked back and the forehead is presented first?
mental
define “position” . what are the common types?
Relationship of fetal denominator to the vertical (anterior, posterior) and horizontal (right, left) planes of birth canal.
Right or left occiput anterior, and right or left occiput posterior are common positions
occiput anterior- baby’s face toward mom’s ______
occiput posterior, baby’s face toward mom’s ______
anterior- face toward mom’s spine
posterior- face toward mom’s anterior
define “dilation”
Degree of patency in centimeters of diameter of the internal os of the cervix
0 (closed) to 10 (fully)
define “effacement”
Measure of the degree of shortening and thinning of the cervix
Expressed as a percentage by which the length of cervix has been reduced
0% no reduction in length
100% no cervix palpable below presenting part
define “station”
The degree of descent of the presenting part through the birth canal as an estimated distance in centimeters from the maternal ischial spines
station: 0, +5, -5
0 station is at level of the spines
+ 5 cm is the perineum (below spines)
- 5 cm is the pelvic inlet (above spines)
define” engagment”
is the descent of the biparietal diameter of the fetal head to a level below the plane of the pelvic inlet
how do you know engagment has taken place?
the lowest portion of the occiput is at or below the level of the maternal ischial spines, Station 0,
define “synclitism”
When the sagittal suture remains parallel to the transverse axis of the pelvic inlet lying exactly midway between the symphysis and sacral promontory
(aka baby faces side of mom instead of sunny side up or down)
what is “asynclitism”? what are the two types?
baby faced to the side (synclitism) but angled more anterior or posterior.
two types- anterior and posterior
what is the definition of labor? what are the different types?
Regular painful contractions resulting in -cervical effacement -cervical dilation May be term or preterm Spontaneous or induced
true labor
Bloody show often present (mucus plug comes out)
Cervix effaces and dilates (most important)
sedation: true vs false labor
sedation stopes false, won’t stop true
false labor
Irregular contractions No change in contraction characteristics No bloody show No cervical change Head may be ballotable (i.e. can be moved upward (Away) by pushing on it)
***what are the 4 stages of labor?
1st stage: beginning (beginning of true labor) to fully dilated
2nd stage: full dilation to delivery of infant
3rd stage: delivery of infant to delivery of placenta
4th stage: delivery of placenta until stable
at what stage can you start to push?
stage 2
3 phases of 1st labor stage
Three phases
Latent 0-3 to 4 cm
Active or acceleration: 3-9cm
Plateau: 9-10 cm
duration of 1st labor stage: primipara (first child) vs multipara (weeds maybe)
Duration:
Primipara 6- 24 hr
Multipara 2-10 hr
active stage rate of 1st labor stage: primipara vs multipara (weeds maybe)
Active stage rate of dilation
Primipara 1cm/hr
Multipara 1.2 to 4 cm/hr
latent phase of 1st labor stage
Regular painful contractions q 2-5min (but variable) Cervical softening and effacement Longest phase; can be prolonged Fetal head usually engaged - around 20 hours
active phase of 1st labor stage
Effacement complete or nearly complete
Contractions harder and more frequent
More rapid dilation with some descent
-around 5 hours
are latent and active stages longer for primipara or multipara
primipara
plateau or deceleration stage of 1st labor stage
Contractions very hard
Dilation may slow some
More descent
Duration more variable
what stage is this?
Cardinal movements of labor
Pushing
Delivery
stage 2
what are the cardinal movements of labor? (in general)
baby following path of least resistance
when is the descent rate the greatest?
Greatest rate is in the deceleration phase of the First Stage and during the Second Stage
what causes the cardinal movement of flexion?
Caused by resistance of birth canal
Baby’s chin approaches its chest
how does flexion influence length of labor for babies that are OA vs OP
OA- smaller presenting diameter-less flexion- shorter labor
OP- larger presenting diamter- full flexion- longer labor
internal rotation: head usually enters the pelvis in what configuration? then what happens?
transversely
Can rotate > 90 degrees to get to OA, 75% of OP will eventually convert to OA
extension: how is the vaginal outlet directed?
Vaginal outlet is directed upward and forward
Extension thus occurs in the outlet and with birth of head
In OP there is combination of flexion and extension
define crowning
when largest diameter is encircled by vulvar ring
external rotation
Restitution
Head returns to align with shoulders and back
what happens in expulsion ?
Anterior shoulder slides under symphysis
Then posterior shoulder over perineal body (then everything else comes out really fast)
Delivery of body
what are the 7 cardinal movements of labor?
Engagement Descent Flexion Internal rotation Extension External rotation Expulsion
Only push after ______ ______
Only push with ________
Only push after complete dilation
Only push with contractions
what parts of the body are delivered in what order? (normally)
- how is this done?
Crowning Delivery of head Anterior shoulder Posterior shoulder Body
*Gentle downward traction till anterior shoulder clears symphysis
Elevate head to deliver posterior shoulder
Body delivered by traction on shoulders- gentle traction
median duration of labor, nulliparous and multiparous (weeds)
Nulliparas:
Total duration - 10.1 hours
Multiparas:
Total duration - 8.2 hours
the 4 Ps: conduct of labor (things that influence the labor)
Powers - how good are contractions (can give oxytocin to increase the strenght)
Passage- defined by bony pelvis
Passenger- baby (correct position and size)
Psyche - mother needs to stay positive
3 ways to measure the force of “powers”
Force measured by
-palpation
-external tocometer
=internal pressure monitor
does the size of the passenger really matter?
Not really- everyone should have the “trial” of labor. a small woman mya be able to deliver a large baby
4 degrees of laceration of the birth canal.
1st degree: (mostly skin)
2nd degree: (fascia and muscles)
3rd degree: (perineal body and anal sphincter)
4th degree: (exposes rectum)
…thoughts about episiotomy (maybe weeds)
Over used, but less popular in recent years
Only if major dystocia or severe tear anticipated
Increases extension of lacerations
More post op pain
Does not prevent pelvic relaxation
how do you prevent tears and episiotomy (6)
Control head:
- Maintain flexion
- Support perineum
- No Ritgen’s maneuver (traction on chin at perineum during head delivery– intended to reduce tears, but actually increases them)
- Avoid rapid extension
- Don’t drag posterior shoulder through perineum
- perineal stretching and support
