Flashcards in Giving Birth: Sherpath Deck (41):
The uterus contracts in a coordinated way. Labor contractions gradually assume a regular pattern of increasing frequency, duration, and intensity. Coordinated labor contractions begin in the uterine fundus and spread downward toward the cervix to propel the fetus through the pelvis.
Uterine contractions are not under conscious control. The mother cannot cause labor to start or stop by conscious effort. Walking or other activity may stimulate existing labor contractions. Anxiety and excessive stress can diminish them.
Labor contractions are intermittent rather than sustained, allowing relaxation of the uterine muscle and resumption of blood flow to and from the placenta.
Increment, Peak, Decrement of contractios
*Occurs as the uterine contraction begins in the fundus and spreads throughout the uterus
*The uterine contraction is the most intense
*The period of decreasing intensity as the uterus relaxes
Frequency of contractions
*The period from the beginning of one uterine contraction to the beginning of the next
*Usually expressed in minutes and fractions of minutes
Duration of contractions
*The length of each uterine contraction from beginning to end
*Usually expressed in seconds
Intensity of contractions
The strength of the uterine contractions:
*Mild uterine contractions often described as feeling like the tip of the nose
*Moderate uterine contractions often described as feeling like the chin
*Firm uterine contractions often described as feeling like the forehead
A woman pregnant for the first time
A woman who has not given birth to a viable infant. The designation “para 0” indicates nulliparity.
A woman who has been pregnant more than once.
Thinning of the cervix
Opening of the cervix
Which is a characteristic of typical labor contractions?
Which phase of the contraction cycle likely would be the most painful for the laboring woman?
Which part of the labor contraction cycle is the nurse describing when stating, “Contractions are 2.5 to 3 minutes apart”?
Which part of the labor contraction cycle is the nurse describing when stating, “Contractions are lasting 40 to 50 seconds?”
Which are progressive changes that occur to the cervix during labor?
The 4 "P's" of the birthing process
What are the 2 powers of birth?
The two powers of labor are uterine contractions and maternal pushing efforts.
What are the passages of birth?
The maternal pelvis and its soft tissues.
What are the passengers of birth?
The fetus plus the membranes and placenta.
What is the psyche of birthing process?
Maladaptive stress responses decrease a woman’s ability to cope during labor. Adaptive responses to stress augment the natural birth process.
What are the components of the passage?
What is the inlet
If the inlet is small, the fetal head may not be able to enter it. Because it is almost entirely surrounded by bone, except for cartilage at the sacroiliac joint and symphysis pubis, the inlet cannot enlarge much to accommodate the fetus. The bony measurements are essentially fixed.
What is the Midpelvis
The narrowest part of the pelvis through which the fetus must pass during birth.
What is the outlet
The angle of the pubic arch also is an important pelvic outlet measure. The angle of the pubic arch should be at least 90 degrees. A narrow pubic arch displaces the fetus posteriorly toward the coccyx as it tries to pass under the arch.
Components of the Birth Process: Passenger
Variations of lie
Variations of Attitude
Variations of Presentation
Variations of presentation: Breech
Variations of lie
The orientation of the long axis of the fetus to the long axis of the woman is the fetal lie. In more than 99% of pregnancies, the lie is longitudinal, or parallel to the long axis of the woman. In the longitudinal lie, either the head or buttocks of the fetus enter the pelvis first. A transverse lie exists when the long axis of the fetus is at right angles to the woman’s long axis; it occurs in less than 1% of pregnancies. An oblique lie is one at some angle between the longitudinal lie and the transverse lie.
Variations of Attitude
The attitude of the fetus is the relation of fetal body parts to each other. As seen below in image ‘A’, the normal fetal attitude is one of flexion, with the head flexed toward the chest and the arms and legs flexed over the thorax. As seen in image ‘B’, the fetal back is curved in a convex C shape in the abnormal attitude of extension.
Variations of Presentation
The fetal part that enters the pelvis first is the presenting part. Presentation falls into three categories: (1) cephalic, (2) breech, and (3) shoulder. The cephalic presentation with the fetal head flexed is the most common. The breech and shoulder presentations are associated with prolonged labor or other problems and are more likely to require cesarean birth.
The cephalic presentation is more favorable than others, for several reasons: The fetal head is the largest single fetal part. After the head is born, the smaller parts follow easily as the extremities unfold. During labor the fetal head can gradually change shape to adapt to the size and shape of the maternal pelvis. The fetal head is smooth, round, and hard, making it an effective part to dilate the cervix, which is also round. The vertex presentation is the most common cephalic presentation and is seen below. The fetal head is fully flexed. This presentation is the most favorable for normal progress of labor because the smallest diameter of the fetal head is presenting first.
Variations in presentation: Breech
The breech presentation has three variations that are identified depending on the relationship of the legs to the body (Figure 16-9). A breech presentation occurs when the fetal buttocks or feet enter the pelvis first and are associated with several disadvantages: The buttocks are not smooth and firm like the head and are less effective at dilating the cervix. By the time the fetal head is deep in the pelvis, the umbilical cord is subject to compression between the baby’s head and the maternal pelvis.
Because the umbilical cord can be compressed after the fetal chest is born, the head must be delivered quickly to allow the infant to breathe. In frank breech presentation the fetal legs are extended across the abdomen toward the shoulders. The complete breech is a reversal of the usual cephalic presentation. The head is flexed, and the knees and hips are also flexed, but the buttocks are presenting. The footling breech occurs when one or both feet are presenting. Most fetuses that present as breech are delivered by cesarean section.
Components of the Birth Process: Psyche
Marked anxiety, fear, or fatigue decreases a woman’s ability to cope with pain in labor. Maternal catecholamines secreted in response to anxiety or fear can inhibit uterine contractility and placental blood flow. Relaxation, however, augments the natural process of labor. Many expectant mothers will have relaxation techniques included in their birthing plan that may be guided by their birthing partner or others in their support system. The nurse’s interactions with the expectant mother will be crucial in creating an environment in which the expectant mother can feel as safe and relaxed as possible. Interventions the nurse can implement to assist with relaxation include visualization, slow breathing patterns, massage, aromatherapy, music, hydrotherapy, and hot and cold therapies.
How might a pubic arch of 85 degrees affect labor?
A pubic arch with an angle less than 90 degrees may impede the fetus from passing under it.
How does cephalic presentation of the fetus facilitate labor?
Allows the fetal head to adapt to the maternal pelvis
Which roles does the maternal psyche play in facilitating childbirth?
*Calmness increases a woman’s ability to cope with pain during labor.
*Relaxation supports the natural process of labor.
Match the laboring woman’s description of her contraction pattern with the most likely phase.
“They don’t bother me that much, but my belly tightens a little each time I have a contraction.”
**Mild, every 5 min, lasting 30-40 sec
“They are getting more intense. I have to breath with them and concentrate.”
**Moderate, every 2-3 min, lasting 40-60 sec
“They are so close together and they really hurt, I can’t do this anymore.”
**Strong, every 1½-2 min lasting 60-90 sec
Which characteristics of effacement and dilatation describe the laboring woman who is closest to delivery?
9cm dilatation, 100% effaced
Transition may be used to describe the intense contractions of fetal descent and final cervical dilatation, about 7 or 8 cm to complete.
Which fetal presentation is ideal for labor?
The fetal head is the largest single fetal part. After the head is born, the smaller parts follow easily as the extremities unfold.
Which type of fetal presentation results most often in caesarean section?
The shoulder presentation is a transverse lie and accounts for less than 1% of births, usually premature. A cesarean birth is necessary.