OB Test 1 Chapter 16 Flashcards
5 P’s
passenger passageway powers Position psychologic factors
What determines how the fetus can move through the birth canal?
the size of the fetal head fetal position fetal lie fetal attitude fetal presentation
What are fontanels and where are they located
membrane filled spaces
located on the head where sutures intersect
Anterior fontanel =
largest and is diamond shaped
Posterior fontanel =
smallest and is triangular shaped
When does the anterior fontanel close
18 months
when does the posterior fontanel close
6-8 week
Overlapping of the bones in the skull that happens while the baby is in the birth canal is called?
Molding
What is fetal presenation
refers to the part of the fetus that enters the pelvic inlet and leads through the birth canal during labor
What are the 3 main presentations
- cephalic (head first)
- Breech (butt, feet, or both first)
- Shoulder
Which is the most difficult presentaion?
Shoulder
What is the presenting part?
is the part of the fetus that lies in the internal os of the cervix
What is fetal lie
lie is the relation of the long axis of the fetus to the long axis or spine of the mother.
What are the 2 primary lies
logitudinal or vertical
and
horizontal, transverse, or oblique
Cephalic Presentation / Breech presenation =
vertical lie
Shoulder Presentation =
Transverse Lie
What is fetal attitude
attitude is the relation of the fetal body parts to eachother.
What is the normal fetal attitude
general flexion
the arms are crossed over the thorax, and the umbilical cord lies between the arms and the legs
Deviations from general flexion can cause difficulty in childbirth
pressure in the mothers back usually means the baby is posterior
What is fetal position
is the relationship of the reference point on the presenting part (occiput, sacrum, mentum [chin] or sinciput) to the mothers pelvis
position is denoted by a three part abbreviation
The first letter of the abbreviation is the location of the presenting part.
Right or Left Side of the mothers pelvis
R or L
The Middle abbriviation stands for the specific presentating part of the fetus
(occiput, sacrum, mentum [chin] or sinciput)
O S M Sc
The final letter is the location of the presenting part in relation to the anterior, posterior, or transverse portion of the mothers pelvis
A, P, T
Normal babies on a vaginal delivery shoud be
ROP
ROA
LOP
LOA
Passageway =
bony pelvis, soft tissue
Full bladder can cause obstruction of
soft tissues of the cervix
What is the classic type of female pelvis
gynecoid
When is the assessment of the bony pelvis done
during the first prenatal visit
The cervix ____, and _____ sufficiently to allow the first fetal portion to decend into the vagina.
effaces (thins) , and Dilates (opens)
Efacing is measured as a
percent
Dilation is measured in
cm
What is primary powers
involuntary uterine contractions
these signal the beginning of labor
What are secondary powers
once the cervix is dilated, voluntary bearing down to compliment primary powers
What position is best for posterior positioned fetus
the all fours position
What is the primary position in the US
Lithotomy
What position can be used to rotate a fetus that is in a posterior postion
lateral position
What stage is the longest stage of labor
1st
What is considered the first stage of labor
is considered to last from the onset of regular contractions to full effacement and dilation of the cervix.
What is the second stage of labor
lasts from the time that the cervix is fully effaced and dilated to the birth of the fetus
normal range is 2-3 hours
What is the third stage of labor
lasts from the birth of the fetus until the placenta is delivered
the placenta is usulayy expelled within 15 min after the birth of the baby
What is the 4th stage of labor
arbitrarily lasts 1-2 hours after delievery of the placenta
What is mechanism of labor
the turns and other adjustments deemed necessary in the human birth process
What are the 7 cardinal movements of the mechanism of labor
- engagement
- decent
- flexion
- internal rotation
- extention
- external rotation
- birth by expulsion
Fetal Adaptation
several important psysiologic adaptions occur in the fetus.
These changes include fetal heart rate, fetal circulation, respiratory movements, and other behaviors.
What is the average fetal heart rate
140 bpm
What is the normal range for fetal heart rate
110 to 160 bpm
The fetal heart rate slows down during
contractions
fetal circulation is effected by what factors
maternal position
uterine contractions
blood pressure
and umbilical cord blood flow
What is the normal rate to be having contractions
every 2-3 minutes for about 45 seconds or so
Certain changes stimulate chemoreceptors in the aorta and carotid bodies to prepare the fetus for initiating respirations immediately after birth.
What are these changes?
fetal lung fluid is cleared from the air passages during labor
fetal oxygen presure decreases
fetal arterial pH decreases
fetal bicarb level decreaes
fetal respiratory movements decrease during labor
(respiratory alk is normal)
Maternal adaptation through labor
cardiac output increases heart rate slightly increases BP increases WBC can increase respiratory rate increases spontaneous voiding skin stretches joint aches back aches
Initially may be euphoric in the first stage then gets serious with some amesia between contractions
motility and gi absorption decrease
progesterone decreases and estrogen and prostaglandins and oxytosin increase
Do not use valsava maneuver because
fetal hypoxia can occur
With regard to primary and secondary powers, the maternity nurse should understand that:
A. Primary powers are responsible for effacement and dilation of the cervix
B. Effacement generally is well ahead of dilation in women giving birth for the first time; they are more together in subsequent pregnancies
C. Scarring of the cervix caused by a previous infection or surgery may make the delivery a bit more painful, but it should not slow or inhibit dilation
D. Pushing in the second stage of labor is more effective if the woman can breathe deeply and control some of her involuntary needs to push, as the nurse directs
A. Primary powers are responsible for effacement and dilation of the cervix
The primary powers are responsible for dilation and effacement; secondary powers are concerned with expulsion of the fetus.
Nurses can advise their clients that all are signs that precede labor except:
A. A return of urinary frequency as a result of increased bladder pressure
B. Persistent low backache from relaxed pelvic joints
C. Stronger and more frequent uterine (Braxton Hicks) contractions
D. A decline in energy, as the body stores up for labor
D. A decline in energy, as the body stores up for labor
A surge of energy is a phenomenon that is common in the days preceding labor.
In order to accurately assess the health of the mother accurately during labor, the nurse should be aware that:
A. The woman’s blood pressure increases during contractions and falls back to prelabor normal between contractions
B. Use of the Valsalva maneuver is encouraged during the second stage of labor to relieve fetal hypoxia
C. Having the woman point her toes reduces leg cramps
D. The endogenous endorphins released during labor raise the woman’s pain threshold and produce sedation
D. The endogenous endorphins released during labor raise the woman’s pain threshold and produce sedation
In addition, physiologic anesthesia of the perineal tissues, caused by the pressure of the presenting part, decreases the mother’s perception of pain.
The nurse knows that the second stage of labor, the descent phase, has begun when:
A. The amniotic membranes rupture
B. The cervix cannot be felt during a vaginal examination
C. The woman experiences a strong urge to bear down
D. The presenting part is below the ischial spines
C. The woman experiences a strong urge to bear down
During the descent phase of the second stage of labor, the woman may experience an increase in the urge to bear down.
All statements about normal labor are true except:
A. A single fetus presents by vertex
B. It is completed within 8 hours
C. A regular progression of contractions, effacement, dilation, and descent occurs
D. No complications are involved
B. It is completed within 8 hours
Although the amount of time varies with each woman, a normal uncomplicated labor is usually completed within 18 hours.
Nurses can help their clients by keeping them informed about the distinctive stages of labor. What description of the phases of the first stage of labor is accurate?
A. Latent: mild, regular contractions; no dilation; bloody show; duration of 2 to 4 hours
B. Active: moderate, regular contractions; 4 to 7 cm dilation; duration of 3 to 6 hours
C. Lull: no contractions; dilation stable; duration of 20 to 60 minutes
D. Transition: very strong but irregular contractions; 8 to 10 cm dilation; duration of 1 to 2 hours
B. Active: moderate, regular contractions; 4 to 7 cm dilation; duration of 3 to 6 hours
The active phase is characterized by moderate, regular contractions; 4 to 7 cm dilation; and a duration of 3 to 6 hours.
Which position would the nurse suggest for second-stage labor if the pelvic outlet needs to be increased? A. Semirecumbent B. Sitting C. Squatting D. Side-lying
C. Squatting
Kneeling or squatting moves the uterus forward and aligns the fetus with the pelvic inlet; this can facilitate the second stage of labor by increasing the pelvic outlet.
Fetal circulation can be affected by many factors during labor. Accurate assessment of the laboring woman and fetus requires knowledge of these expected adaptations. Which factor will not affect fetal circulation during labor?
A. Fetal position
B. Uterine contractions
C. Blood pressure
D. Umbilical cord blood flow
A. Fetal position
Maternal position may affect fetal circulation; however, fetal position is unlikely to disturb umbilical blood flow.
Fetal circulation can be affected by many factors during labor. Accurate assessment of the laboring woman and fetus requires knowledge of these expected adaptations. Which factor will not affect fetal circulation during labor?
A. Fetal position
B. Uterine contractions
C. Blood pressure
D. Umbilical cord blood flow
C. Blood pressure
Maternal blood pressure is likely to have a significant effect on fetal circulation.
Concerning the third stage of labor, nurses should be aware that:
A. The placenta eventually detaches itself from a flaccid uterus
B. The duration of the third stage may be as short as 3 to 5 minutes
C. It is important that the dark, roughened maternal surface of the placenta appear before the shiny fetal surface
D. The major risk for women during the third stage is a rapid heart rate
B. The duration of the third stage may be as short as 3 to 5 minutes
The third stage of labor lasts from birth of the fetus until the placenta is delivered. The duration may be as short as 3 to 5 minutes, although up to 1 hour is considered within normal limits.
