Chapter 8 - Labor triggers + 5 P Flashcards
uterine muscles are stretched to the threshold point, leading to the release of…
prostaglandin + oxytocin
>stim contraction
increased pressure on the cervix stim the ____ causing the release of ___ by the ___
nerve plexus> oxytocin> pituitary gland
progesterone effects
-quieting effect on uterus
oxytocin + prostaglandin MOA
inhibit calcium binding in muscle cells
>incr intracellular calcium levels
>activate contraction
Maternal labor triggers
1 incr estrogen
2 incr oxytocin
3 incr prostoglandins
4 decr progesterone
as placenta ages, it begins to ____, triggering ____
deteriorate> invitation of contraction
Fetal labor triggers
1 placenta ages/deteriorates
2 synthesis of prostaglandins
3 incr in fetal cortisol> decr progesterone + incr prostaglandin
fetal cortisol
- prod by fetal adrenal glands
- incr + acts on placenta to decr progesterone + incr prostaglandin
Factors affecting labor
[5 P’s]
Powers Passage Passenger Psyche Position
Power
involuntary UC + voluntary pushing/bearing down
-propels + delivers bb + placenta fr uterus
pacemakers in the uterus
signals to posterior pituitary to secrete oxytocin + stim contraction
how does contraction affect upper + lower uterine?
upper: contracts pushing bb down
lower: less active, becomes thinner
___ is responsible for dilation + effacement of cervix in _____ stage of labor
UC> first stage
each contractions has a
allows woman + myometrium to pause for a rest
that was temporarily reduced during contraction phase
during the contraction phase, the BF…
to the uterus + placenta is temporarily reduced
during the resting phase or uterine relaxation phase
- allows blood flow to return to uterus + placenta
- much of fetal xchange of O2 + nutrients + wastes occurs
- rest for mom + myometrium
w every contraction, ___ of blood leaves the _____ + moves back into ____
500 mL> utero-placental unit> maternal circulation
–gets rid of waste + replenishes O2
UC is described by…
- frequency
- duration
- intensity
UC Frequency
time from start of 1 contraction to the start of another
- in minutes
ex) occurring Q 3-4 mins
UC duration
time from start 1 contraction to end of contraction
- in seconds
ex) lasts 40-50 seconds
UC Intensity
mild (tip of nose, easily intended)
mod (chin, resistant to indentation)
strong (forehead, cannot be intended)
the cervix is considered fully/completely dilated when it is
10 cm
-can no longer be palpated on vaginal examination
effacement
the shortening + thinning of the cervix
-measured by percentage
Ferguson reflex
the urge to push/bear down
-activated when the presenting part stretches the pelvic floor
effects of estrogen + relaxin during labor
softens cartilage + incr elasticity of the ligaments
station
refers to the relationship of the ischial spines to the presenting part of the fetus
-for assessing fetal descent during labor
station 0
the narrowest diameter the fetus must pass thru
major factors in the birthing process
the relationship of the passenger + the passage
passenger
the fetus
- affected by fetal skull, attitude, lie, presentation, position, + size
- *the position of the fetus r/t the birth canal is the most critical
- size of fetus is less significant
any position other than cephalic
indicated c section
molding
ability of fetal head to change shape + accommodate the pelvis
fetal skull is composed of…
2 parietal bones + 2 temporal bones + frontal _ occipital
biparietal diameter [BPD]
- 9.25 cm
- largest transverse skull measurement
- most important indicator of head size
fetal attitude or posture
relationship of fetal parts to one another
-noted by flexion + extension of fetal joints
goal fetal attitude/posture during term
- convex fetal back
- flexed head w chin against chest
- arms crossed over thorax
- thighs flexed on abdomen
fetal lie
refers to long axis (spine) of bb in relation to long axis of women
types of fetal lie
longitudinal or transverse
bb cannot be delivered if fetal lie is…
transverse
fetal presentation
determined by part or pole of the bb that first enters the pelvic inlet
times of fetal presentation
cephalic (head first)
breech (pelvis first)
shoulder (shoulder first)
presenting part
specific fetal structure lying nearest to the cervix
how to further classify cephalic presentation
by degree of flexion or extension of head + neck:
- vertex
- frontum/brow
- face
VERTEX cephalic presentation
head is sharply flexed, chin tucked
-denominator is occiput
FRONTUM/BROW cephalic presentation
partial extension of neck + brow
- presenting is brow
- denominator is frontum
FACE cephalic presentation
neck is sharply extended, arching to the back like bb is facing up
-denominator is chin
Breech presentation
presenting part is butt or feet
how to further classify breech presentation
- complete
- frank
- footling
COMPLETE breech presentation
- flexion of thigh + legs extended over anterior surface
- criss cross apple sauce
FRANK breech presentation
complete flexion of thighs + legs
-like folding, head to toe
FOOTLING breech presentation
extension of one or both legs so that one or both feet are presenting
Transverse presentation
shoulder is presenting part
compound presentation
fetus assumed unique posture
factors that negatively affect PSYCHE
- unrealistic expectation> cause anxiety
- bad past experience
- hx of complications
- recent immigrants w different birth experiences in their countries
- difficulty conceiving + unplanned pregnancies
1st theory of labor support
during labor, women feel uniquely vulnerable bc unfamiliar environment, unfamiliar personnel, lack of privacy
»leads to anxiety
»decr in confidence + competence
2nd theory of labor support
- enhanced passage by encouraging mobility + using gravity
- decr stressed response
anxiiety during labor is assoc w…
-high levels of epinephrine> >abnormal FHR >decr UC >low apgar score >longer labor
Position
maternal positions during labor + birth
freedom of mvmt
enhance ability to cope w pain
upright position
- great for first stage of labor
- gives advantage of gravity in second stage
- walking, sitting, kneeling, squatting
benefits of upright position
- decr the compression of descending aorta + ascending vena cava
- aids in descent
- shorter labors
- less severe lacerations
- less need for episiotomies
- less fatigue
- improved circulation
gravity neutral positions
side-lying + hands-knees
