CH 12: Processes of Birth Flashcards
The nurse is explaining the physiology of uterine contractions to a group of nursing students. Which statement best explains the maternal-fetal exchange of oxygen and waste products during a contraction?
a.
Little to no affect
b.
Increases as blood pressure decreases
c.
Diminishes as the spiral arteries are compressed
d.
Continues except when placental functions are reduced
ANS: C
During labor contractions, the maternal blood supply to the placenta gradually stops as the spiral arteries supplying the intervillous space are compressed by the contracting uterine muscle. The exchange of oxygen and waste products is affected by contractions. The exchange of oxygen and waste products decreases. The maternal blood supply to the placenta gradually stops with contractions.
- The nurse is directing an unlicensed assistive personnel (UAP) to obtain maternal vital signs between contractions. Which statement is the appropriate rationale for assessing maternal vital signs between contractions rather than at another interval?
a.
Vital signs taken during contractions are inaccurate.
b.
During a contraction, assessing fetal heart rate is the priority.
c.
Maternal blood flow to the heart is reduced during contractions.
d.
Maternal circulating blood volume increases temporarily during contractions.
ANS: D
During uterine contractions, blood flow to the placenta temporarily stops, causing a relative increase in the mother’s blood volume, which in turn temporarily increases blood pressure and slows the pulse. Vital signs are altered by contractions but are considered accurate for a period of time. It is important to monitor the fetal response to contractions, but the question is concerned with the maternal vital signs. Maternal blood flow is increased during a contraction.
- Uncontrolled maternal hyperventilation during labor results in
a.
metabolic acidosis.
b.
metabolic alkalosis.
c.
respiratory acidosis.
d.
respiratory alkalosis.
ANS: D
Rapid deep respirations cause the laboring woman to lose carbon dioxide through exhalation, resulting in respiratory alkalosis. Hyperventilation does not cause respiratory acidosis, metabolic acidosis, or metabolic alkalosis.
- Which mechanism of labor occurs when the largest diameter of the fetal presenting part passes the pelvic inlet?
a.
Extension
b.
Engagement
c.
Internal rotation
d.
External rotation
ANS: B
Engagement occurs when the presenting part fully enters the pelvic inlet. Extension occurs when the fetal head meets resistance from the tissues of the pelvic floor and the fetal neck stops under the symphysis. This causes the fetal head to extend. Internal rotation occurs when the fetus enters the pelvic inlet. The rotation allows the longest fetal head diameter to conform to the longest diameter of the maternal pelvis. External rotation occurs after the birth of the head. The head then turns to the side so the shoulders can internally rotate and are positioned with their transverse diameter in the anteroposterior diameter of the pelvic outlet.
- The laboring patient asks the nurse how the labor contractions cause the cervix to dilate. The nurse responds that labor contractions facilitate cervical dilation by
a.
promoting blood flow to the cervix.
b.
contracting the lower uterine segment.
c.
enlarging the internal size of the uterus.
d.
pulling the cervix over the fetus and amniotic sac.
ANS: D
Effective uterine contractions pull the cervix upward at the same time the fetus and amniotic sac are pushed downward. Blood flow decreases to the uterus during a contraction. The contractions are stronger at the fundus. The internal size becomes smaller with the contractions; this helps push the fetus down.
- Pregnant patients can usually tolerate the normal blood loss associated with childbirth because of which physiologic adaptation to pregnancy?
a.
A higher hematocrit
b.
Increased leukocytes
c.
Increased blood volume
d.
A lower fibrinogen level
ANS: C
Women have a significant increase in blood volume during pregnancy. After birth, the additional circulating volume is no longer necessary. The hematocrit decreases with pregnancy due to the higher fluid volume. Leukocyte levels increase during labor; however, that is not the reason for the toleration of blood loss. Fibrinogen levels increase with pregnancy.
- The nurse is assessing the duration of a patient’s labor contractions. Which method does the nurse implement to assess the duration of labor contractions?
a.
Assess the strongest intensity of each contraction.
b.
Assess uterine relaxation between two contractions.
c.
Assess from the beginning to the end of each contraction.
d.
Assess from the beginning of one contraction to the beginning of the next.
ANS: C
Duration of labor contractions is the average length of contractions from beginning to end. Assessing the strongest intensity of each contraction assesses the strength or intensity of the contractions. Assessing uterine relaxation between two contractions is the interval of the contraction phase. Assessing from the beginning of one contraction to the beginning of the next is the frequency of the contractions.
- Which physiologic event is the key indicator of the commencement of true labor?
a.
Bloody show
b.
Cervical dilation and effacement
c.
Fetal descent into the pelvic inlet
d.
Uterine contractions every 7 minutes
ANS: B
The conclusive distinction between true and false labor is that contractions of true labor cause progressive change in the cervix. Bloody show can occur before true labor. Fetal descent can occur before true labor. False labor may have contractions that occur this frequently but is usually inconsistent.
- Which factor ensures that the smallest anterior-posterior diameter of the fetal head enters the pelvis?
a.
Station
b.
Flexion
c.
Descent
d.
Engagement
ANS: B
The anterior-posterior diameter of the head varies with how much it is flexed. In the most favorable situation, the head is fully flexed and the anterior-posterior diameter is the suboccipitobregmatic, averaging 9.5 cm. The station is the relationship of the fetal presenting part to the level of the ischial spine. Descent is the moving of the fetus through the birth canal. Engagement occurs when the largest diameter of the fetal presenting part has passed the pelvic outlet.
- An increase in urinary frequency and leg cramps after the 36th week of pregnancy are an indication of
a.
lightening.
b.
breech presentation.
c.
urinary tract infection.
d.
onset of Braxton-Hicks contractions.
ANS: A
As the fetus descends toward the pelvic inlet near the end of pregnancy, increased pelvic pressure occurs, resulting in greater urinary frequency and more leg cramps. Breech presentation does not cause urinary frequency and leg cramps. A urinary tract infection may cause urinary frequency but with burning and would not cause leg cramps. Braxton-Hicks contractions are irregular and mild and occur throughout the pregnancy.
- A patient just delivered her baby via the vaginal route. The patient asks the nurse why the baby’s head is not round, but oval. Which explanation should the nurse provide the patient?
a.
This results from molding.
b.
This results from lightening.
c.
This results from the fetal lie.
d.
This results from the fetal presentation.
ANS: A
The sutures and fontanels allow the bones of the fetal head to move slightly, changing the shape of the fetal head so it can adapt to the size and shape of the pelvis. Lightening is the descent of the fetus toward the pelvic inlet before labor. Lie is the relationship of the long axis of the fetus to the long axis of the mother. Presentation is the fetal part that first enters the pelvic outlet.
- A patient whose cervix is dilated to 6 cm is considered to be in which phase of labor?
a.
Latent phase
b.
Active phase
c.
Second stage
d.
Third stage
ANS: B
The active phase of labor is characterized by cervical dilation of 5 to 6 cm. Historically, the latent phase is from the beginning of true labor until 3 cm of cervical dilation. Recent research has suggested that the latent phase be considered to last up until 5 to 6 cm. dilated. The second stage of labor begins when the cervix is completely dilated until the birth of the baby. The third stage of labor is from the birth of the baby until the expulsion of the placenta.
- The nurse is assessing a patient in the active phase of labor. What should the nurse expect during this phase?
a.
The patient is sociable and excited.
b.
The patient is requesting pain medication.
c.
The patient begins to experience the urge to push.
d.
The patient experiences loss of control and irritability.
ANS: B
During the active phase of labor, contraction intensity and discomfort increase to the point where women often request pain medication. Sociability and excitability occur during the latent phase. The urge to push occurs at the end of the transition phase or the second stage of labor. Loss of control and irritability occur during the transition phase of labor.
- A laboring patient asks the nurse how she will know that the contraction is at its peak. The nurse explains that the contraction peaks during which stage of measurement?
a.
The acme
b.
The interval
c.
The increment
d.
The decrement
ANS: A
The acme is the peak or period of greatest strength during the middle of a contraction cycle. The interval is the period between the end of the contraction and the beginning of the next. The increment is the beginning of the contraction until it reaches the peak. The decrement occurs after the peak until the contraction ends.
- A patient in labor presents with a breech presentation. The nurse understands that a breech presentation is associated with
a.
more rapid labor.
b.
a high risk of infection.
c.
maternal perineal trauma.
d.
umbilical cord compression.
ANS: D
The umbilical cord can compress between the fetal body and maternal pelvis when the body has been born but the head remains within the pelvis. Breech presentation is not associated with a more rapid labor. There is no higher risk of infection with a breech birth. There is no higher risk for perineal trauma with a breech birth. Most breech presentations are now delivered by caesarean birth.