Transcript Fetal Presentation

Dr. Areefa Al Bahri
Ch. 5
The Birth Experience
Physiological, psychological, and emotional
changes that take place during pregnancy help to prepare
the woman for labor and birth. Near the end of the pregnancy,
the fetus continues to develop physiological abilities
that facilitate successful adaptation for the transition
from in utero life to the outside environment.
The Process of Labor and Birth
A number of forces affect the progress of labor and help to
bring about childbirth. These critical factors are often
referred to as the “P’s” of labor:
1. Powers (physiological forces)
2. Passageway (maternal pelvis)
3. Passenger (fetus and placenta)
4. Passageway Passenger and their relationship
(engagement, attitude, position)
5. Psychosocial influences (previous experiences, emotional
status)
POWERS
The powers are the physiological forces of labor and birth that
include the uterine contractions and the maternal pushing
efforts. The uterine muscular contractions, primarily responsible
for causing cervical effacement and dilation, also move the fetus
down toward the birth canal during the fi rst stage of labor.
Uterine contractions are considered the primary force of labor.
Once the cervix is fully dilated, the maternal pushing efforts
serve as an additional force. During the second stage of labor,
use of the maternal abdominal muscles for pushing (the
secondary force of labor) adds to the primary force to facilitate
childbirth.
Characteristics of Uterine Contractions
Contractions are a rhythmic tightening of the uterus that occurs
Between contractions, the uterus normally returns to a state of
complete relaxation. This rest period allows the uterine
muscles to relax and provides the woman with a short recovery
period that helps her to avoid exhaustion. In addition, uterine
relaxation between contractions is important for fetal
oxygenation as it allows for blood flow from the uterus to the
placenta to be restored.
With each contraction, the uterus elongates. Elongation causes a
straightening of the fetal body so that the upper body is pressed
against the fundus and the lower, presenting part is pushed
toward the lower uterine segment and the cervix. The pressure
exerted by the fetus is called the fetal axis pressure. As the
uterus elongates, the longitudinal muscle fibers are stretched
upward over the presenting part. This force, along with the
hydrostatic pressure of the fetal membranes, causes the cervix
to dilate (open).
The coordinated efforts of the contractions help to bring about
effacement and dilatation of the cervix. Effacement is the process of
shortening and thinning of the cervix.
For example, if a cervix has thinned to half the normal length of a
cervix it is considered to be 50% effaced. Dilation is the opening and
enlargement of the cervix that progressively occurs throughout the
first stage of labor. Cervical dilation is expressed in centimeters and
full dilation is approximately 10 cm. With continued uterine
contractions, the cervix eventually opens large enough to allow the
fetal head to come through. At this point, the cervix is considered
fully dilated or completely dilated and measures 10 cm.
Maternal Pushing Efforts
After the cervix has become fully dilated, the laboring woman
usually experiences an involuntary “bearing down” sensation
that assists with the expulsion of the fetus. At this time, the
woman can use her abdominal muscles to aid in the expulsion.
It is important to remember that the cervix must be fully
dilated before the patient is encouraged to push. Bearing down
on a partially dilated cervix can cause cervical edema and
damage and adversely affect the progress of the labor.
Women who have a strong urge to push often do so more
effectively than women who force themselves to push without
experiencing any sensations of pressure.
PASSAGEWAY
The passageway consists of the maternal pelvis and the soft
tissues. The bony pelvis through which the fetus must pass is
divided into three sections: the inlet, midpelvis (pelvic cavity),
and outlet. Each of these pelvic components has a
unique shape and dimension through which the fetus must
maneuver to be born vaginally. In human females, the four
classic types of pelvis are the gynecoid, android, platypelloid,
and anthropoid.
PASSENGER
The passenger is referred to as the fetus and the fetal
membranes. In the majority (96%) of pregnancies, the fetus
presents in a head-fi rst position. The fetal skull, usually the
largest body structure, is also the least flexible part of the
fetus. However, because of the sutures and fontanels, there is
some flexibility in the fetal skull. These structures allow the
cranial bones the capability of movement and they overlap in
response to the powers of labor. The overlapping or
overriding of the cranial bones is called molding.
Fetal Presentation
The fetal presentation refers to the fetal part that enters the
pelvic inlet first and leads through the birth canal during labor.
The fetal presentation may be cephalic, breech, or shoulder.
The part of the fetal body first felt by the examining finger
during a vaginal examination is the “presenting part.” The
presenting part is determined by the fetal lie and attitude.
CEPHALIC PRESENTATION
fetal head will be first to come into contact with the maternal
cervix. Cephalic presentations occur in approximately 95% of
pregnancies.
There are four types of cephalic presentations
Vertex. The fetal head presents fully flexed. This is the
most frequent and optimal presentation as it allows the
smallest suboccipitalbregmatic diameter to present. It is called
a “vertex presentation.”
Military. In the military position, the fetal head presents
in a neutral position, which is neither flexed nor extended. The
occipitofrontal diameter presents to the maternal pelvis and the
top of the head is the presenting
part.
Brow. In the brow position, the fetal head is partly
extended. This is an unstable presentation that converts
toFace.
Face presentation.
the fetal head is fully extended. The submentobregmatic
diameter presents to the maternal pelvis and the face is the
presenting part
The following advantages are associated with a cephalic
presentation:
• The fetal head is usually the largest part of the infant.
Once the fetal head is born, the rest of the body usually delivers
without complications.
• The fetal head is capable of molding. There is sufficient time
during labor and descent for molding of the fetal head to occur.
Molding helps the fetus to maneuver through the maternal birth
passage.
• The fetal head is smooth and round, which is the optimal
shape to apply pressure to the cervix and aid in dilation.
Other presentations (e.g., breech, shoulder) are associated with
difficult, prolonged labor and often require cesarean births.
They are called malpresentations.
BREECH PRESENTATION
A breech presentation occurs when the fetal buttocks enter the maternal
pelvis first. Breech presentations occur in approximately 3% of births and
are classified according to the attitude of the fetal
hips and knees. Breech presentations are more likely to occur in preterm
births or in the presence of a fetal abnormality such as hydrocephaly (head
enlargement due to fluid) that prevents the head from entering the pelvis.
They are also associated with abnormalities of the maternal uterus or pelvis.
Since many factors can compromise
the normal labor and birth process associated with breech presentations,
delivery is usually accomplished via cesarean section.
There are three types of breech presentations
Frank. The frank breech is the most common of all
breech presentations
Complete (Full). The complete, or full, breech position is
the same as the flexed position with the fetal buttocks
presenting first. The legs are typically flexed.
Footling. In the footling breech position, one or both of
the fetal leg(s) are extended with one foot (“single footling”) or
both feet (“double footling”) presenting first into the maternal
pelvis.
Several disadvantages are associated with a breech presentation:
1. An increased risk for umbilical cord prolapsed because the
presenting part may not be covering the cervix (i.e., footling
breech).
2. The presenting part (buttocks, feet) is not as smooth and hard
as the fetal head and is less effective in dilating the cervix.
3. Once the fetal body (abdomen) is delivered, the umbilical cord
can become compressed.
Rapid delivery may be difficult since the fetal head is usually the
largest body part and in this situation, there is no time to allow for
molding. In response to adverse outcomes that have been
associated with vaginal breech births, the American College of
Obstetricians and Gynecologists (ACOG, 2006) has published a
Committee Opinion concerning planned breech deliveries.
SHOULDER PRESENTATION
The shoulder presentation is a transverse
lie (Fig. below). This presentation is rare
and occurs in fewer than 1% of births. When
a transverse lie is present, the maternal
abdomen appears large from side to side,
rather than up and down. In addition, the
woman may demonstrate a lower than
expected (for the gestational age) This
presentation occurs most often with preterm
birth, high parity, prematurely ruptured
membranes, hydramnios, and placenta
previa. It is important for the nurse to
promptly identify a transverse lie or
shoulder presentation since the infant will
almost always require a cesarean birth.
Station
Station refers to the level of the presenting part in relation to the maternal ischial
spines. In the normal female pelvis, the ischial spines represent the narrowest
diameter through which the fetus must pass. The ischial spines is a landmark to
identify station zero. To visualize the location of station zero, an imaginary line
may be drawn between the ischial spines.
Engagement has occurred when the presenting part is at station zero. When the
presenting part lies above the maternal ischial spines, it is at a minus station.
Therefore, a station of minus 5 (–5) cm indicates that the presenting part is at the
pelvic inlet. Positive numbers indicate that the presenting part has descended past
the ischial spines.
During labor, the presenting part should continue to descend into the pelvis,
indicating labor progress. As labor advances and the presenting part descends, the
station should also progress to a numerically higher positive station. If the station
does not change in the presence of strong, regular contractions, this finding may
indicate a problem with the relationship between the maternal pelvis and the fetus
(“cephalopelvic disproportion”).
Position
Position refers to the location of a fixed reference point on the fetal
presenting part in relation to a specific quadrant of the maternal
pelvis (Fig. 12-10). The presenting part can be right anterior, left
anterior, right posterior, and left posterior. These four quadrants
designate whether the presenting part is directed toward the front,
back, right, or left of the passageway.
Passageway (passenger)
The passageway and the passenger have been identified as two of
the factors that affect labor. The next “P” is the relationship
between the passageway (maternal pelvis) and the passenger
(fetus and membranes). The nurse assesses the relationship
between the two when determining the engagement, station, and
fetal position.
Engagement
Engagement is said to have occurred when the widest diameter of
the fetal presenting part has passed through the pelvic inlet. In a
cephalic presentation, the largest diameter is the biparietal; in
breech presentations, it is the intertrochanteric diameter.
Engagement can be determined by external palpation or by
vaginal examination. In primigravidas, engagement usually
occurs
PSYCHOSOCIAL INFLUENCES
The first four P’s discussed address the physical forces of labor.
The last “P” (psychosocial influences) an effect on parents such
as their readiness for labor and birth, level of educational
preparedness, previous experience with labor and birth,
emotional readiness, cultural influences, and ethnicity. Transition
into the maternal role, and most likely, into the paternal role as
well, is facilitated by a positive childbirth experience. A number
of internal and external influences can affect the woman’s
psychological well-being during labor and birth.
Culturally oriented views of childbirth help to shape the woman’s
expectations and ongoing perceptions of the birth experience. The
nurse’s understanding of the cultural values and expectations
attached to childbirth provide a meaningful framework upon
which to plan and deliver sensitive, appropriate care. Cultural
considerations for the laboring woman encompass many elements
of the birth experience including choice of a birth support person
strategies for coping with contractions, pain expression and relief
and food preferences.
Signs and Symptoms of Impending Labor
Before the onset of labor, a number of physiological changes
occur that signal the readiness for labor and birth. These changes
are usually noted by the primigravid woman at about 38 weeks of
gestation. In multigravidas, they may not take place until labor
begins. It is important for nurses to empower pregnant women
and their families by teaching them about the signs and symptoms
of impending labor. Providing guidelines about when to contact
the health care provider or come to the birth facility helps to
demystify the sometimes confusing events that surround birth and
lessen the anxieties that can accompany the onset of labor.
LIGHTENING
At about 38 weeks in the primigravid pregnancy, the
presenting part (usually the fetal head) settles downward
into the pelvic cavity, causing the uterus to move
downward as well. This process, called lightening, marks
the beginning of engagement. This downward settling of
the uterus may decrease the upward pressure on the
diaphragm and result in easier breathing. The downward
settling may also lead to the following maternal symptoms:
• Leg cramps or pains
• Increased pelvic pressure
• Increased urinary frequency
• Increased venous stasis, causing edema in the lower
extremities
• Increased vaginal secretions, due to congestion in the
vaginal mucosa
BLOODY SHOW
During pregnancy the cervix is plugged with mucus. The mucus
plug acts as a protective barrier for the uterus and its contents
throughout the pregnancy. As the cervix begins to soften, stretch,
and thin through effacement, there may be rupture of the small
cervical capillaries. The added pressure created by engagement of
the presenting part may lead to the expulsion of a blood mucus
plug, called bloody show. Its presence often indicates that labor
will begin within 24 to 48 hours. Late in pregnancy, vaginal
examination that involves cervical manipulation may also produce
a bloody discharge that can be confused with bloody show.
Rupture Of The Membranes
About 12% of pregnant women experience spontaneous rupture of the amniotic
sac (“ruptured membranes” or “ruptured bag of waters”) prior to the onset of
labor. In the majority of pregnancies, the amniotic membranes rupture once
labor is well established, either spontaneously or by amniotomy, the artificial
rupture of the membranes by the primary care provider.
Rupture of the membranes is a critical event in pregnancy. If the membranes do
rupture at home, the woman should be taught to immediately contact the
birthing center who will advise her to report for an examination.
It is important for the woman to note the color, amount, and odor of the
amniotic fluid. The fluid should be clear and odorless.
A yellow green tinged amniotic fluid may indicate infection or fetal passage of
meconium and this finding always signals the need for further assessment and
fetal heart rate monitoring. Urinary incontinence (frequently associated with
urgency, coughing, and sneezing) is sometimes confused with ruptured
membranes. The presence of amniotic fluid can be confirmed by a Nitrazine
tape test or by a fern test.
First Stage of Labor
This stage begins with the onset of regular uterine contractions and ends with
complete dilation of the cervix. woman may not always recognize when true
labor actually begins. The first stage of labor is most often the longest stage and
its duration can vary considerably among women. The first stage of labor is
divided into three distinct phases: latent, active, and transition. Factors such as
analgesia, maternal and fetal position, the woman’s body size and her level of
physical fitness can also affect the length of labor.
LATENT PHASE
Labor pains are often initially felt as sensations similar to painful menstrual
cramping and are usually accompanied by low back pain. Contractions during
this phase are typically about 5 minutes apart, last 30 to 45 seconds, and are
considered to be mild. During the latent phase cervical effacement and early
dilation (0 to 3 cm) occurs. The latent phase of labor can last as long as 10 to 14
hours as the contractions are mild and cervical changes occur slowly.
ACTIVE PHASE
The active phase of labor is characterized by more active contractions. The
contractions become more frequent (every 3 to 5 minutes), last longer (60
seconds), and are of a moderate to strong intensity. During the active labor
phase, the woman becomes more focused on each contraction and tends to draw
inward in an attempt to cope with the increasing demands of the labor. Cervical
dilation during this phase advances more quickly as the contractions are often
more efficient. While the length of the active phase is variable, nulliparous
women generally progress at an average speed of 1 cm of dilation per hour
and multiparas at 1.5 cm of cervical dilation per hour.
TRANSITION PHASE
The transition phase is the most intense phase of labor. Transition is
characterized by frequent, strong contractions that occur every 2 to 3 minutes
and last 60 to 90 seconds on average. Fortunately, this phase often does not take
long because dilation usually progresses at a pace equal to or faster than active
labor (1 cm/hr for a nullipara and 1.5 cm/hr for a multipara).
Assessment of the Fetus During Labor and Birth
Fetal assessments include the identification of fetal position and
presentation, and the evaluation of the fetal status. Nurses use a variety of
assessment techniques including observation, palpation, and auscultation.
When assessing a woman in labor, the nurse is able to use observation and
interview skills from the moment the woman comes through the door.
Astute observation assists the nurse in assessing the patient’s level of pain,
her coping abilities
Baseline Fetal Heart Rate
The normal baseline fetal heart rate at term is 110 to 160 beats per minute (bpm). There
are two abnormal variations of the baseline: tachycardia (baseline above 160 bpm); and
bradycardia (baseline below 110 bpm).
TACHYCARDIA.
Tachycardia is generally defi ned as a sustained baseline fetal heart rate greater
than 160 beats per minute for a duration of 10 minutes or longer. A number of
conditions are associated with fetal tachycardia:
• Fetal hypoxia: The fetus attempts to compensate for reduced blood flow by
increasing sympathetic stimulation of the central nervous system (CNS).
Maternal fever:
• Maternal medications: Both parasympathetic drugs
(i.e., atropine, scopolamine) and beta-sympathetic drugs (tocolytic drugs used
to halt contractions) can have a stimulant effect and increase the fetal heart rate.
• Infection: uterine infection (amnionitis)
• Fetal anemia: In response to a decrease in hemoglobin, the FHR increases to
compensate and improve tissue metabolism.
• Maternal hyperthyroidism: Thyroid-stimulating hormone (TSH) may cross
the placenta and stimulate the fetal heart rate (Tucker, 2004).
BRADYCARDIA
Bradycardia is defined as baseline FHR of less than 110 to 120 bpm.
Fetal bradycardia may be associated with:
• Late hypoxia: Myocardial activity becomes depressed and lowers
the fetal heart rate.
• Medications: Beta-adrenergic blocking drugs (e.g., propanolol
[Inderal]).
• Maternal hypotension:
• Prolonged umbilical cord compression
• Bradyarrhythmias: With complete heart block, the FHR
baseline is often as low as 70 to 90 bpm.
Variability
Variability of the FHR is manifested by fluctuations in the baseline fetal
heart rate observed on the fetal monitor. The pattern denotes an irregular,
changing FHR rather than a straight line that indicates few changes in the
rate. The variability of the FHR is a result of the interplay between the fetal
sympathetic nervous system, which assists to increase the heart rate and the
parasympathetic nervous system, which acts to decrease the heart rate.
The absence of or undetected variability is considered non-reassuring.
FHR variability is indicative of an adequately oxygenated neurological
pathway in which impulses are transmitted from the fetal brain to the
cardiac conduction system (Fox, Kilpatrick, King, & Parer, 2000).
Conversely, the absence of variability may indicate normal variations such
as fetal sleep (the sleep state should not last longer than 30 minutes), a
response to certain drugs that depress the CNS, such as analgesics
(meperidine [Demerol], tranquilizers (diazepam [Valium]),
ACCELERATIONS
An acceleration is defined as an increase in the FHR of 15 bpm above the
fetal heart baseline that lasts for at least 15 to 30 seconds. Accelerations
are considered a sign of fetal well-being when they accompany fetal
movement. Thus, when a fetus is active in utero, accelerations are
normally present. When contractions are present, accelerations are often
noted as a response to the contraction.
DECELERATIONS
Decelerations are defined as any decrease in FHR below the baseline
FHR. Decelerations are further defined according to their onset and are
characterized as early, variable, and late.
Early Decelerations
Early decelerations are characterized by a deceleration in the FHR that
resembles a mirror image to the contraction. Therefore, the onset of the
deceleration begins near the onset of the contraction, and the FHR
returns to baseline by the end of the contraction. Early decelerations are
usually repetitive and are commonly observed during active labor and
descent of the fetus
Variable Decelerations
Variable decelerations, as the name implies, are decelerations that are
variable in terms of their onset, frequency, duration, and intensity. The
decrease in FHR below the baseline is 15 bpm or more, lasts at least 15
seconds, and returns to the baseline in less than 2 minutes from the time
of onset (NICHD, 1997) (Fig. 12-19). The deceleration is unrelated to the
presence of uterine contractions. Variable decelerations are thought to be
a result of umbilical cord compression. Thus, the degree by which the
cord
is compressed (partially versus completely) can affect the severity of the
deceleration. The American College of Obstetricians and Gynecologists
(ACOG, 2005) classifies variable decelerations as significant when the
FHR falls below 70 bpm and lasts longer than 60 seconds. In addition, the
Society of Obstetricians and Gynaecologists of Canada (SOGC, 2005)
concurs and further identifi es “non-reassuring” or “atypical” variable
decelerations as:
Late Decelerations
This type of deceleration does not resolve until after the contraction
has ended. Late decelerations indicate the presence of uteroplacental
insufficiency, a decline in placental function. a decrease in blood flow
from the uterus to the placenta results in fetal hypoxia and late
decelerations. Late decelerations require prompt attention and
reporting. The longer the late decelerations persist, the more serious
they become. For example, late decelerations in the presence of an
oxytocin infusion may signal a need to immediately
discontinue the oxytocin infusion, especially if uterine
hyperstimulation is suspected. Nursing interventions that should be
implemented immediately include reporting the late decelerations,
changing the maternal position, discontinuing the oxytocin infusion,
increasing the intravenous fl uids, and administering oxygen by mask.
The Cardinal Movements
The cardinal movements, or mechanisms of labor, have been used to
describe how the fetus (in a vertex presentation) passes through the birth
canal and the positional changes required to facilitate birth (Fig. 12-23). The
cardinal movements are presented in the order in which they occur.
Descent
Four forces facilitate descent, which is the progression of the fetal head into
the maternal pelvis: (1) pressure of the amniotic fluid; (2) direct pressure of
the uterine fundus on the fetal breech; (3) contraction of the maternal
abdominal muscles; and (4) extension and straightening
of the fetal body. The fetal head enters the maternal inlet in the occiput
transverse or the oblique position because the pelvic inlet is widest from side
to side. The sagittal suture is equidistant from the maternal symphysis pubis
and sacral promontory. The degree of fetal descent is measured
by stations.
Flexion
Flexion occurs as the fetal head descends and comes into
contact with the soft tissues of the pelvis, the muscles of the
maternal pelvic floor, and the cervix. The resistance
encountered with these structures causes the fetal chin to flex
downward onto the chest. This position allows the smallest
fetal diameters to enter the maternal pelvis.
Internal Rotation
To fit into the maternal pelvic cavity, which is widest in the
anteroposterior diameter, the fetal head must rotate.
Extension
As the fetal head passes under the maternal symphysis pubis, it
meets with resistance from the pelvic floor. The head pivots and
extends with each maternal pushing effort. The head is born in
extension as the occiput slides under the symphysis and the face is
directed toward the rectum. The fetal brow, nose, and chin then
emerge. Restitution Internal rotation causes the fetal shoulders to
enter the maternal pelvis in an oblique position. After the head is
delivered in the extended position, it rotates briefly to the position
it occupied when it was engaged in the inlet. This movement is
termed restitution. The 45-degree turn of the fetal head facilitates
realignment with the long axis of the body.
External Rotation
As restitution continues, the shoulders align in the anteroposterior
diameter, causing the head to continue to turn farther to one side
(external rotation). The fetal trunk moves through the pelvis with the
anterior shoulders descending first.
Expulsion
After external rotation, maternal pushing efforts bring the anterior
shoulder under the symphysis pubis. Lateral flexion of the shoulder
and head occurs and the anterior, then posterior, shoulder is born.
Once the shoulders are delivered, the rest of the body quickly
follows.
Second Stage of Labor
The second stage of labor commences with full dilation of the
cervix and ends with the birth of the infant. Often the woman or
nurse may suspect that the woman has entered the second stage of
labor because of the patient’s urge to push or the presence of
involuntary bearing down efforts. The contractions often remain
very similar to those experienced during the transition stage.
It is important to encourage the patient to rest between pushing in
order to maintain her energy throughout the second stage. The
duration of the second stage is variable and may be influenced by
several factors such as parity; the type and amount of analgesia or
anesthesia administered; the frequency, intensity, and duration of
contractions; maternal
efforts in pushing, and the support the patient receives.
Achieving A Position Of Comfort
Positions such as squatting and kneeling may also help to increase
the dimensions of the maternal pelvis. Assuming a hands and
knees position or leaning over a table or chair helps to take
pressure off the maternal spine and often reduces backache
commonly associated with a fetal occipital–posterior position
Preparation For The Birth
As the fetus descends, the woman experiences an increasing urge to
bear down due to pressure of the fetal head. As the fetal head
progresses downward, the perineum begins to stretch, thin out, and
move anteriorly. The amount of bloody show may increase at this time
and the labia begin to part with each contraction. The fetal head, which
may be observable at the vaginal.
Crowning, which means that birth is imminent, occurs when the fetal
head is encircled by the vaginal introitus. The woman may also feel
intense pressure in the rectum and a need to evacuate her bowels.
Some women may feel as though they are losing control and a variety
of emotions (e.g., irritability, fear, embarrassment, and helplessness)
may be displayed.
EPISIOTOMY
Episiotomy is a surgical incision of the perineum that is
performed to enlarge the vaginal orifice during the second
stage of labor (Carroli & Belizan, 2006). At that time,
many physicians routinely performed episiotomies based on
the belief that surgical enlargement of the vaginal opening
would prevent complications such as fetal trauma, and severe
lacerations, and later maternal problems such as cystocele,
rectocele, dyspareunia, and uterine prolapse. In studies where
episiotomy had been performed for medical indications, the
results demonstrated positive benefits. The use of episiotomy
for medical indications, which include instrumentation during
birth (forceps or vacuum), a need to expedite the birth
(evidence of fetal compromise), or in the event of maternal
exhaustion.
Two different methods are used for the episiotomy. The
most common method is the midline or median episiotomy.
An incision is made from the vaginal opening downward
toward the rectum. A midline episiotomy is easily repaired,
heals quickly, and is associated with less postoperative pain
than a mediolateral episiotomy. However, the primary
disadvantage of a midline episiotomy is the risk of third- and
fourth-degree lacerations with extension through the rectal
sphincter.
Third Stage of Labor
The third stage of labor is the period of time from the
birth of the baby to the complete delivery of the placenta.
This stage usually lasts 5 to 10 minutes, and may last up
to 30 minutes. Once the baby is born, the uterine cavity
immediately becomes smaller. The change in the interior
dimension of the uterus results in a reduction in the size
of the placental attachment site.
The following
clinical indicators signal that separation of the placenta
from the uterus has occurred:
• The uterus becomes spherical in shape.
• The uterus rises upward in the abdomen due to the
descent of the placenta into the vagina.
• The umbilical cord descends further through the
vagina.
• A gush of blood occurs once the placenta detaches
from the uterus. As the placenta separates from the uterine wall, it is
important that the uterus continues to contract. The contractions
minimize the bleeding that results from the open blood vessels left at
the placental attachment site. Failure of the uterus to contract
adequately with separation of the placenta can result in excessive
blood loss or hemorrhage. To enhance the uterine contractions after
expulsion of the placenta, oxytocic medications are often given.
Oxytocin is administered either by the intravenous (IV) route or by
NURSING CARE OF THE MOTHER DURING
THE THIRD STAGE OF LABOR
After the birth of the infant, the nurse observes for signs
that the placenta has separated from the wall of the uterus.
The uterus is palpated to determine the rise upward as
well as the characteristic change in shape from one
resembling
a disk to that of a globe. The nurse may ask the
woman to push again, to facilitate in the delivery of the
placenta. If 30 minutes have elapsed from completion of
the second stage of labor and the placenta has not yet been
expelled, it is considered to be “retained”. (See Chapter 14
for further discussion.) Oxytocic medications such as Pitocin
and Syntocinon are often administered at the time of the
delivery of the placenta. These drugs are used to stimulate
uterine contractions, thereby minimizing the bleeding from
the placental attachment site and reducing the risk of
postpartum hemorrhage. The nurse administers oxytocic
medications according to institutional protocol. If a
peripheral intravenous infusion has been established,
oxytocin 10 to 20 units may be added to the intravenous
infusion. If no intravenous infusion is present, 10 units of
oxytocin may be administered intramuscularly
In situations where there is excessive blood loss, the physician
may order up to 40 units of oxytocin per liter of intravenous
infusion fluid. Other medications such as methylergonovine
maleate (Methergine) may be given intramuscularly to control
blood loss.
During this time the nurse continues to assess the volume of blood
loss and monitor the patient’s vital signs, paying close attention to
the blood pressure and heart rate. Once the placenta has been
delivered, the nurse carefully examines it to ensure that all
cotyledons are intact.
If any part of the placenta is missing, the nurse immediately
reports this fi nding to the attending physician. Because retained
placental fragments can contribute to postpartum hemorrhage or
infection, the physician may perform a manual exploration of the
uterus to remove any remaining placental tissue.
Immediate Nursing Care of the Newborn
Once the newborn has been born, the primary care provider (physician or
certified nurse midwife) places the infant on the mother’s abdomen (if the
infant is stable). This immediate contact between mother and newborn
provides reassurance to mother regarding the overall well-being of the
baby, and begins the attachment process. Several physiological adaptations
must occur to facilitate the adjustment of the newborn to the extrauterine
environment. Of primary importance is the initiation of the newborn’s
respirations, a process that results in the replacement of fetal lung fluid
with air. In most situations, the actions of drying the newborn and
performing nasopharyngeal suctioning, if needed, provide adequate
stimulation to initiate the newborn’s respiratory effort.
Immediate Nursing Care of the Newborn
While respirations are being established, the newborn’s cardiovascular
system is also undergoing major adaptations to allow the flow of
deoxygenated blood into the lungs for gas exchange. Fetal circulation
transitions to neonatal circulation after closure of the ductus arteriosus,
the foramenovale, and the ductus venosus.
The modified Trendelenburg position facilitates the drainage of mucus
from the newborn’s nasopharynx and trachea. The nurse suctions the
newborn’s nose and mouth with a bulb syringe as needed. Preventing
heat loss in the neonate constitutes an important nursing role. Before
the infant is placed on the mother’s abdomen, the nurse dries the infant,
discards the wet linens, and applies warm blankets. Skin-to-skin contact
between the mother and baby also helps to maintain the newborn’s
temperature.
THE APGAR SCORING SYSTEM
The nurse assesses this transition stage after one minute and
again after 5 minutes, using the Apgar Scoring
HEART RATE. The priority assessment of the newborn is the heart rate.
On auscultation or palpation, the nurse recognizes an absent heart rate or
heart rate less than 100 bpm as a signal for resuscitation.
RESPIRATORY EFFORT. The newborn’s vigorous cry best indicates
adequate respiratory effort, the next most important assessment after birth. A
weak or absent cry is a signal for intervention.
MUSCLE TONE. The nurse determines the newborn’s muscle tone by
assessing the response to the extension of the extremities. Good muscle
tone is noted when the extremities return to a position of flexion.
REFLEX IRRITABILITY. The nurse assesses reflex irritability by
observing the newborn’s response to stimuli such as a gentle stroking motion
along the spine or flicking the soles of the feet. When this stimulation elicits
a cry, the score is 2. A grimace in response to stimulation scores 1, and no
response is a score of 0.
COLOR. The nurse assesses skin color for pallor and cyanosis. Most
newborns exhibit cyanosis of the extremities at the 1-minute A pgar check,
and this normal finding is termed acrocyanosis. A score of 2 indicates that
the infant’s skin is completely pink. Newborns with darker pigmented skin
are assessed for pallor and acrocyanosis
summary points
◆ Each patient’s labor and birth experience is unique, and nurses play a
vital role in facilitating a positive outcome for the patient, infant, and
family.
◆ Nurses recognize that the labor and birth experience is influenced by a
myriad of factors such as maternal age and well-being, social support, and
cultural and religious beliefs and practices.
◆ Nurses need a strong knowledge base about the physiological processes
of labor and birth in order to provide safe and effective care.
◆ In each of the four stages of labor, the nurse uses well-developed
assessment skills to recognize the normal progression of labor, to identify
potential risks to the patient and fetus, and to identify how and when to
intervene and consult with other health care providers..
summary points
◆ The overall goal of intrapartal nursing care is to promote
comfort and safety of the patient, the fetus, and the newborn
infant.
◆ A positive nurse–patient relationship in which the woman
feels cared for and informed will empower her in coping with
her labor.
◆ Nurses include the patient and her support person(s) in the
planning and delivery of care.
◆ The nursing care given throughout labor and birth is
an important determinant of the woman’s overall perception
of her childbirth experience.