Chapter 9: nursing care during labor and childbirth Flashcards
labor
a physiological process during which the fetus, umbilical cord, placenta, and amniotic membranes are expelled from the uterus, accomplished through uterine contractions, cervical effacement and dilation
- usually begins between 38 weeks and 42 weeks of gestation
theories about the onset of labor
- increased levels of oxytocin
- oxytocin stimulates prostaglandin production
oxytocin
a pituitary hormone secreted into the bloodstream that stimulates the uterine muscle, causing myometrial activity
proaglandins
hormone-like substances which affects tissues, including contraction and relaxation of the smooth muscle, causing cervical softening and increased uterine muscle sensitivity
the placenta produces progesterone, which relaxes…
uterine muscle by hindering impulse conduction; progesterone levels decline toward the end of pregnancy, allowing estrogen to stimulate contractions
the corticotropin releasing hormone hypothesis
maturing fetus produces cortisol; the placenta then converts it into estriol. rising levels of estriol produces an imbalance with estradiol, triggering labor
the uterine stretch theory
uterus becomes overstretched, leading to a natural expulsion of the contents
uterine muscle layers
external
internal
middle
external uterine muscle layer
arches over the fundus and extends to the ligaments supporting the uterus
internal uterine muscle layer
has fibers that act as sphincters around the opening of the fallopian tubes and internal opening of the cervix
middle uterine muscle layer
composed of dense network of fibers and blood vessels that contract after placental delivery to prevent blood loss
musculature changes in the pelvic floor
- Levator ani and fascia pull the vagina and rectum upward and forward with each contraction
- pressure of the fetal head causes these muscles to thin from 5cm to 1cm at the time of birth
signs of labor: bloody show
- blood tinged mucus (mucous plug) from the cervix noted any time before or during labor
- not everyone has it, different from bleeding. mucusy blood tinged slime
signs of labor: burst of energy
- “nesting” wherein the woman wants to complete many projects before the baby’s arrival, noted about 24-48 hours before labor begins
signs of labor: spontaneous rupture of membranes (SROM)
- “water breaking” manifested as a large gush or a small trickle of fluid
- may rupture any time during labor
- fluid should be clear with no offensive odor
- a yellow or green (meconium)amniotic fluid may indicate an unhealthy fetus, should be reported immediately to the hcp –> hypoxia, aspiration
- some women don’t rupture and needs to be artificially ruptured
signs of labor: lightening
noticed by the mother after the 38th week of pregnancy after engagement occurs
engagement
the fetus descends or drops into the pelvis
signs of labor: contractions
- Braxton Hicks contractions are irregular, mild contractions that begin during the second trimester and do not produce cervical effacement and dilation
- in true labor, uterine contractions are regular, become more intense as time passes, and may radiate from the lower back or pelvis to the abdomen
- the contraction start mildly, gets stronger, progresses to a peak, and then fades away
effacement
the cervix-thinning process caused by the shortening of the muscles of the upper uterine segment and longitudinal traction on the cervix
- measured in percentages; a thick uneffaced cervix is 0%, a fully thinned cervix is 100%
dilation
the opening of the closed cervix to approx 10cm or large enough to accommodate the fetal head
dilation and effacement is faster for the…
second and subsequent labors
true labor contractions
- regular intervals
- increasingly more intense as labor progresses
- increased duration over time
- discomfort usually begins in the back and radiates to the front
- cause effacement and dilation
- may intensify with walking
- unchanged w/ warm shower or rest
difference between true and false labor contractions
- do nt increase in duration
- do not cause cervical effacement and dilation
- may cease w/ rest or a warm shower
- do not intesify w/ walking
critical factors in labor: “7 P’s”
passage
passenger
powers
position
psyche
pain management
patience
passage
- the route through which the fetus must pass to be delivered vaginally
- the pelvis: most im portant to the outcome of labor; must be measured by the hcp at the first prenatal visit to determine if size is adequate for a vaginal delivery
- the hormone relaxin causes softening of the cartilage, allowing the pelvis to stretch and llowing the pelvis to stretch and allow passage of the fetus; relaxin affects all joints of the body, making the term pregnant woman at risk of falling due to the loosening of her pelvic joints, knees, ankles
- yield to the pressure of the fetal presenting part, usually the head
passenger
- refers to the fetus w/ the placenta
- fetal head: the frontal, parietal, and occipital bones are not fused to allow the bones to overlap as the head passes through the pelvis (molding)
- the optimal position for the fetal head at birth is fully flexed w/ chin on chest
- fetal lie: position of the fetus in the uterus referring to how the fetal spine lines up w the mother’s spine: longitudinal, transverse, oblique
longitudinal lie
a fetus that is lying parallel w/ mother
transverse lie
a fetus is lying perpendicular to the mother’s bodyob
lique lie
a fetus that is lying at an angle between longitudinal and transverse
fetal presentation
cephalic: head is the presenting part most common and easiest to deliver
shoulder: will require c section
breech: buttocks are presenting part
footling breech: feet are presenting part
fetal position
first letter: indicates whether presenting part is tilted towards left or right ofmaternal pelvis
second letter: indicates presenting part of fetus o for occipital or s for sacrum
third letter: indicates the location of the presenting part in relationship to the anterior, transverse, or posterior part of the maternal pelvis
fetal attitude
refers to the positioning of the fetus’ body parts
fetal station
measurement in cm of the fetal head in relationship to the maternal ischial spines in the pelvis
ranges from -5cm to +5cm
powers
- refer to the power of the uterine contractions and the woman’s ability to push
phases of uterine contractions
increment
acme
decrement
increment
onset and build up of inensity of the cotraction
acme
peak of the contraction
decrement
the subsiding of the contraction
descriptions of contractions
onset
duration
frequency
intensity
onset
the exact time a contraction begins
duration
the actual time a contraction lasts from beginning to end