process of labor and birth Flashcards
when does the onset of labor usually occurs?
between the 38 and 42 weeks of pregnancy
“P” of labor
Powers, passageway, passenger, passageway+passenger and their relationship(engagement, attitude, position), psychosocial influences
on of the factors that include the uterine contraction and the maternal pushing effort
POWERS
considered as the primary force of labor
uterine contractions
secondary force of labor that adds to the primary force to facilitate childbirth
pushing (use of maternal abdominal muscles)
rhythmic tightening of the uterus that occurs intermittently. this action shortens the individual uterine muscle fibers and aids in the process of cervical effacement and dilation, and postpartal involution.
contractions
the reduction of uterine size after birth
involution
what are the 3 distinct components of contraction
increment, acme, decrement
changes in uterine musculature caused by contraction
the upper portion of the uterus becomes thicker and more active. the lower segment becomes thinned-walled and passive.
the boundary between the upper and lower uterine segment becomes marked by a ridge on the inner uterine surface, known as “physiological retraction ring”
the pressure exerted by the fetus
fetal axis pressure
measured from the beginning of one contraction to the beginning of of the next contraction
frequency of contraction
measured from the start on one contraction to the end of the same contraction
duration of contraction
this is measure by uterine palpation and is described as mild, moderate, and strong
intensity of contraction
when the uterus fundus remains soft at the acme of a contraction, the contraction intensity is describe as?
mild
when there is an inability to indent the uterus at the acme of contraction, the contraction intensity is describe as?
strong
pressure sensitive device that is used externally and applied against the uterine fundus
tocodynamometer
this does not give accurate data regarding the intensity of contraction because there are many variables (maternal position, obesity)
resting pressure in the uterus between contractions
10-12mm Hg
pressure of contraction during acme during early labor
25-40mm Hg
pressure of contraction during active labor
50-70mm Hg
pressure of contraction during transition
70-90mm Hg
pressure of contraction during maternal pushing in the second stage
70-100mm Hg
characteristic of uterine contraction during early labor
weak and irregular. they usually last for about 30 sec and occur every 5 to 7 min
what happens to maternal anus during labor and delivery
anus evert and the interior rectal wall is exposed as the fetal head descends forward
the process of shortening and thinning of the cervix
effacement
is the opening and enlargement of the cervix the progressively occurs throughout the first stage of labor. it is expressed in cm
dilation
laboring woman usually experience this sensation when the cervix has become fully dilated
bearing down-assist in the expulsion of the fetus
adverse effect of bearing down when cervix is partially dilated
cervical edema, adversely effect the progress of labor. Initiate pushing only when the cervix is completely dilated!!
bony pelvis through which the fetus must pass is divided to 3 section, which are??
inlet, midpelvis, and outlet
least flexible part of the fetus
fetal skull
the overlapping or overriding of the cranial bones
molding
this diameter is the major transverse diameter of the fetal head
biparietal diameter
the most favorable situation of the head during labor
when the head is fully flexed and the anteroposterior diameter is the suboccopitobregmatic, 3.7 inches
refers to the relationship of the long axis of the woman t to the long axis of the fetus
fetal lie
the head to tailbone axis of the fetus is the same as the woman’s , the fetus is in what lie?
longitudinal lie
what part of the fetal body enters the pelvis first in longitudinal lei
either fetal head or buttocks
the head to tailbone axis of the fetus is at 90-degree angle to the woman
transverse or horizontal lie
this describes the relationship of the fetus’ body parts to one another
fetal attitude
describe fetal position
the fetal head is flexed so that the chin touches the chest., the arms are flexed and folded across the chest, the thighs are flexed on the abdomen, and the calves are flexed against the posterior aspects of the thighs
fetal attitude that occurs when thee chin is not touching the chest but is in an alert, or military position. this position causes the occipital diameter to present to the birth canal.
moderate flexion
this usually does not interfere with the labor
fetal attitude occurs when the brow or face of the head presents to the birth canal
partial extension
refers to the fetal part that enters the pelvic inlet first and leads through the birth canal during labor
fetal presentation (cephalic, breech, shoulder)
what does fetal lie and attitude determine?
presenting part
fetal presentation when the fetal head presents fully flexed. this is also the most frequent and optimal presentation because it allows the smallest suboccipitalbregmatic diameter to present
vertex
the fetal head presents in a neural position, which is neither flexed nor extended. the occipitofrontal diameters presents to the maternal pelvis and the top of the head is the presenting part
military position
in this position, the fetal head is partly extended this is an unstable presentation
Brow
in this position, the fetal head is fully extended and the occiput is near the fetal spine
face
breech and shoulder presentation are called??
malpresentations
when does breech presentation are more likely to occur?
preterm birth, or in the presence of hydrocephaly