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Slide 1 |
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Labor
is the bridge between pregnancy & motherhood. For the woman in labor,
this is the most intense experience of pregnancy. The
process begins between 38 and 40th week. The exact cause of onset
is not understood. There are several hypothesis: Progesterone withdrawal → relaxation of the myometrium,
whereas estrogen stimulates
myometrial contractions and production of prostaglandins. As you will learn
later, prostaglandin E is used to
induce labor. During labor, prostagIandin → the connective tissue in the cervix to
soften, thin out, and open during labor. Oxytocin,
a hormone produced by the pituitary, plays a major role in the onset and
maintenance of contractions during the labor process. Corticotropin-releasing hormone makes the uterus more sensitive
to oxytocin and the prostaglandins. Different theories for one of the most
emotional experiences. Start on Chapter 15. We’ll cover parts Chapters 15 through 20. Each chapter has Key Terms at the beginning and Chapter Highlights as summaries. |
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Slide 3 |
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Final
weeks of pregnancy: mother/baby prepare for birth. Five important factors : the passage, the fetus, the relationship
between the passage and the fetus, the forces of labor, and psychosocial
considerations. Often
called the 5 “P”s of Labor: Passageway, Passenger, Powers, Position, and Psychologic responses |
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Slide 4 |
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PASSAGE : Birth
passage – 3 sections of “true pelvis”
– inlet, pelvic cavity (midpelvis), & outlet. Four classifications : gynecoid , android, anthropoid, & platypelloid. See
Table 15-2: Implications of Pelvic Type for Labor & Birth p 310 The
Caldwell-Moloy (1933) classification of pelvises is widely used to
differentiate bony pelvis types. See
Figure 15-1 , p 311 Gynecoid
is most common, with diameters favorable to vaginal delivery. |
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Slide 5 |
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PASSENGER:
Fetal head: Considerations: face, base of skull, & vault of
cranium (roof). Bones in face fused but vault has movable bones; overlap
under pressure – molding. Sutures –membranous
spaces between bones; intersections – fontanelles
(‘soft spot”) Landmarks:
mentum – chin; sinciput – brow; vertex – space between fontanelles; occiput – occipital bone |
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Slide 6 |
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Fetal
attidude – relationship of fetal parts to one another: norm: mod
flexion of head, flexion of arms unto chest, & flexion of legs to abdomen Fetal lie –
relationship of cephalocaudal axis (spinal column) of fetus to c. a. of
mother longitudinal: parallel transverse: fetal c.a. is 90°
to woman’s spine Fetal
Presentation – determined by fetal lie and by the body part that
enters the pelvic passage first. The portion of the fetus is referred to as
the presenting part. Fetal presentation may be cephalic,
breech, or shoulder. |
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Presentation: Fetal
presentation may be cephalic, breech, or shoulder. Cephalic (head) occurs
97%. Breech (feet) & shoulder may be difficult – called malpresentations. Cephalic
presentation, head is completely flexed onto chest; smallest diameter
(suboccipitobregmatic) presents. The occiput is the presenting part. In
your book: Figure 15-6: Military-
top of head Fig B ; brow – head is
partially extended – largest diameter ©; face
– (D). |
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Engagement – when largest diameter of
presenting part reaches or passes through pelvic inlet. Figure 15-7, p 314 The biparietal
diameter (BPD) of fetal head settles into inlet of pelvis. In most instances,
the occiput is at the level of the ishial spines () station. Station –refers to the relationshio of
presenting part to an imaginary line drawn between the ischial spines of the
maternal pelvis. If the presenting part is higher than the ischial spines,
the station has a negative #, referring
to centimeters above 0 station..Minus 5 is at the pelvic inlet. Positive #s = presenting part has passed
the ischial spines. Positive (+) 4 is at the outlet. See Figure 15-8, p 315 Fetal position – relationship of the designated
landmark of fetal presenting part to
the left or right side of the maternal pelvis. The designated landmarks are
vertex: the occiput; in face
presentation: the mentum. In breech: the sacrum; for shoulder: the acromion
process of the scapula. If directed to side, it is designated as transverse. The landmark on the
fetal presenting part r/t four
imaginary quadrants: left anterior, right anterior, left posterior, and right
posterior, meaning: Is the presenting part directed toward the front, back,
left or right of the passage? Three notations: Right ® or left (L)
side of maternal pelvis The landmark of
fetal presenting part: occiput (O); mentum (M), sacrum (S), or acromion
process (A). Anterior (A),
posterior (P), or transverse (T ) Figure 15-9 p 316. Click back to slide
7 |
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Slide 9 |
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Power: Primary
forces: is the uterine
contraction → complete effacement and dilation of the cervix. Secondary
forces: use
of abdominal muscles to push during the 2nd stage of labor. Pushing force adds to the primary
force after the cervix is fully dilated. Contractions
have
a rhythmic pattern, with periods of
relaxation between, allowing the woman to rest. This resting period
allows for restoration of placental
circulation: important to uterine muscles but also for the baby’s
oxygenation. Increment: the
building up and longest; acme –
peak; and decrement or letting
up. Characteristics:
frequency: time between beginning
of one contraction to the beginning of the next. Duration: beginning
to completion of a single contraction. Intensity
– strength of contraction. Experienced nurse can estimate by palpating the
fundus (top) during the contraction.
Mild: the uterine wall can be indented; strong, it cannot be indented.
Intensity can be measured directly with an intrauterine
probe. Look
at Figure 15-10, p 317 |
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Slide 10 |
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Power
of forces |
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Slide 11 |
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Transition
to new role – couple; permanent change in lifestyle, relationships, &
self-image.; differences between primi and multi: “losing it” – being out of
control; fear of pain; birthing plan: will it be honored? |
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Most
primigravidas and many multigravidas experience the following S & Sx of
labor: Lightening – the fetus
settles into pelvic outlet (review: engagement); leg cramps, ↑ pelvic
pressure, leg edema, ↑ vaginal secretions Braxton
Hicks contractions – (irregular, intermittent contractions or “Practice”
throughout pregnancy, like menstrual cramps. Strong → woman in false labor Cervical
changes
– rigid, firm cervix softens or “ripens” Bloody show – mucus plug is expelled → exposed
cervical capillaries →
pink-tinged secretions Rupture of
membranes
– ROM (not range of motion). 12% before labor begins. Then 80% go into labor
within 24 hrs. Watch carefully: if fetus not engaged, cord can prolapse with
fluid gush. Inc risk for infection Sudden burst
of energy – 24 – 48 hrs /a delivery Other: weight loss
1-3 lbs, N&V, diarrhea True
Vs False labor: contractions of TRUE labor → progressive dilatation
& effacement of cervix; regular & inc in frequency, duration, &
intensity; pain starts in back & radiates to abdomen. Walking intensifies pain. False
labor doesn’t; woman feels foolish (tell story of VICKY). Table
15-4: Comparison of True & False, p 321 |
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Four stages of labor: First stage: the longest stage occurs between
onset of true labor and the point of cervical dilation and effecement. Second stage is the expulsion of the
fetus; third stage – delivery of placenta; and fourth stage – 1st 4 hrs /p delivery of placenta First stage:
divided into 3 phases Latent – begins
with onset of regular contractions, with contractions q 15 -20 min, lasting 20 -30 secs, gradually lnc to q 5 – 7 min, 30 – 40 secs duration. Little
or no cervical dilation. Women stay home. Phase ends when cervix is 3 cm.
Lasts 8.6 hrs for primi, < 6 for multi. Active phase –
begins 4 cm, ends when dilated to 7cm; contractions 2 – 3 mins, 40 – 60 secs;
cervix should dilate about 1 to 1.5 cm /hr.
Primi – avg 4.6 hrs, multi 2.4 hrs Transition phase –
shortest, most intense. Dilation from 8 to 10 cm; contractions q 1.5 – 2
mins, lasting 60 – 90 secs (pain & rest about same). Lasts avg 3.6 hrs
for Primi; varies with multi. Woman becomes restless, angry, wants to go
home, wants a C-sec, N&V, etc. Withdraws from support (spouse, coach,
etc), leaving partner feeling useless. NURSE IS VITAL at this point to both.
NURSE must prepare for 2nd stage. Second stage:
cervix is completely dilated & effaced; known as pushing stage; up to 3 hrs for primi, < 30 mins in multi. The woman bears down, abdominal muscles
contract, & help fetal head descend. When fetal head is visible at vulvar
opening, crowning has occurred and
birth is imminent. Some women feel relief, birth is near; others feel
frightened and overwhelmed. Pt can assume different positions. In US,
lithotomy position most common. Positional changes
of fetus: called cardinal movements: Descent: progression of head into pelvis d/t
pressure of amniotic fluid, the contracting uterus, the effects of contractions on mother’s
abdominal muscles and diaphragm, and the extension and straightening of the
fetus. Head enters at an oblique or transverse position Flexion – resistance from soft pelvic
tissues → flexion of chin
against chest :: smallest fetal diameter Internal rotation – fetal head must rotate to
accommodate the pelvis; head rotates from left to right Extension – fetal head pivots under symphysis
pubis. Head emerges through extension, followed by occiput, then the face,
and finally the chin Restitution – internal rotation causes shoulders
to enter pelvis in an oblique position and neck becomes twisted. When head is
delivered, the neck untwists and aligns with long axis of fetus. External rotation – shoulders rotate, turning head
further to one side Expulsion – anterior shoulder slips under
symphysis pubis, followed by posterior shoulder. Once shoulders are
delivered, the trunk follows. (Sometimes rather quickly!) Figure 15-13
(illustration), p 325 Birth sequence
Figure 15 -12, p 324 |
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Slide 14 |
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Click
back and forth |
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Slide 15 |
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Third stage
–
begins as soon as baby delivered and lasts until placenta delivered.
Combination of contractions and involution (growing smaller) . Placenta detaches from wall within 10 – 15
mins → inc bleeding; delivery of placenta follows. Classic signs: uterus
“rounds up” into ball, moves upward, the cord lengthens, followed by rush of
vaginal blood. Once placenta delivered, contractions close off arterioles,
uterus continues to shrink, & bleeding ↓. Figure
15-14, p 326: “shiny” Shultze or “Dirty” Duncan Fourth stage – “recovery
stage” or 1st 4 hours /p delivery. Avg blood loss is 250 –
500ml;blood is redistributed in venous bed, → mod drop in BP, inc pulse
pressure, and mod tachycardia. fundus is midline, |
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Maternal responses:
during labor: with each contraction, 300-500 mls of blood forced into
maternal circulation → ↑ cardiac out put which ↑ with pain
and anxiety. In supine position,
cardiac output ↓, HR ↑, stroke volume↓. Best to
assume side-lying position. BP ↑ during contractions and pushing. Respiratory: anxiety & pain →
hyperventilation & respiratory alkalosis; muscular activity → mild
metabolic acidosis. Acid-base balance
- norm /p 24 hrs Renal & GI –
↑ in pressure and edema to bladder can lead to over distension; ↑
in renin & angiotension help
control uteroplacental blood flow. GI – gastric emptying delayed → risk
of aspiration if general anesthesia necessary Immune/blood – WBCs
inc to 25,000 – 30,000. Blood glucose ↓ (energy during contractions),
insulin requirements drop Pain – gate-control
theory: mechanism aloows ↑
or↓ in impulses to CNS. Pain can be reduced through tactile stimulation
such as back rubs, sacral pressure, effleurage; and CNS-controlled activities such as suggestion, distractions,
& conditioning. Pain varies: 1st
stage: stretching, pressure, hypoxia of muscles during contraction; 2nd
stage – hypoxia to uterine muscles, stretching of vagina & perineum and
pressure on adjoining . Figure 15 – 16, p 328. What about fetal
response? Heart rate changes in response to intracranial pressure from
maternal contractions; fetal blood pressure protects fetus during
contractions; fetus responds to light, sound, & touch, beg 37 wks |
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Determine
if true or false labor: True:
contractions regular, becoming stronger, lower back radiating to abdomen,
more intense with walking cervical changes, fetus moving to lower pelvis. False:
irregular contractions which stop with walking, pain abdominal and stopping
with comfort measures. Data
collection: Review
prenatal data for baseline information; Identify
expected problems such as bleeding, diabetes, screening results Previous
delivery info; check EDC Interview:
time of onset of regular contractions, frequency, pain level Vaginal
DC, characteristics, ROM, Nitrazine test of pH (ROM – alkaline), “Fern” test Last
PO intake’ Birth plan; childbirth prep, cultural considerations, support |
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Assessment:
VS, Leopold’s Maneuvers for position of fetus Figure 16-5, p 343 Vaginal
exam to gauge dilation – Figure 16-3 & 16-4, p 342 Fetal
monitoring: auscultating through Doppler or fetoscope, after Leopold’s
Maneuvers to determine position. FHR
most clearly heard at fetal back. Figure 16-6. Electronic
fetal monitoring produces continuous tracing. Can be external through US. A
tranducer is placed on maternal abdomen. The transducer produces sound waves
which bounce off the fetal heart and
picked up by electronic monitor. Differentiate between Maternal and
fetal HR. Go
to next slide. |
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Slide 19 |
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Internal
monitoring requires an internal spiral electrode.The membranes must be
ruptured, the cervix dilated to 2 cm or >, the presenting part must be
down against the cervix, and the examiner must recognize which fetal part is
presenting (to avoid injury). A
sterile spiral electrode is inserted into vagina against presenting part,
& rotated until it attaches. Provides accurate, continuous movement, with
a clearer signal and minus interruptions d/t maternal or fetal movements. |
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Evaluations: Normal
– 120 160 bpm. Variability is the
change from baseline that occurs over seconds or minutes (the wiggles) Abnormal variations
are > 160 bpm (tachycardia) or < 120 bpm (bradycardia). Tachycardia is
considered (sustained rate of 161 bpm
) ominous if accompanied by late decelerations,
severe variable decels, or ↓ variability. Bradycardia with rate
< 110 – 120 bpm during a 10 min period can be ominous or benign. When
accompanied by late decels, considered a sign of fetal distress. Accelerations: the transient ↑ in FHR
normally caused by fetal movement. In response to contractions, considered a
good sign. Decelerations: periodic decreases in FHR from norm
baseline. Categorized as early, late,
and variable. Early -
Fetal head is compressed → central vagal stimulation →
early deceleration. Onset is before onset of uterine contraction, considered
benign. Late – caused by uteroplacental
insufficiency d/t dec blood flow & O2
to fetus during contraction.
Occurs after onset of contractions. Considered non-reassuring, but not
necessarily eminent for childbirth. Variable – umbilical cord is compressed, ↓
blood flow between placenta & fetus. Needs further assessment. Look on pate 349,
Figure 16 – 11. |
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Slide 21 |
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Keep
watch on Mom’s contractions. Keep
vaginal exams to minimum to prevent infections. Figure 16-2, p 341 |
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Slide 22 |
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During prenatal
visits, patient learns to come to birthing unit ROM Regular, frequent
contractions (nullipara- 5 mins apart, multiparas – 10 – 15 mins apart x1hr Vaginal bleeding. Admission process
influences the course of hospital stay. Refer to Teaching About… p 358 Nursing
management:1st stage: Assist to bed;
side-lying position; obtain admission data; collect clean ureing speciman;
dipstick urine for presence of protein, glucose, ketones ; draw labs for Hct,
Hgb, T&C, serological testing per institution policy; signed informed
consent Provide education Family expectations
– emotional support, comfort measures, advocacy for dreams for birth
experience; praise for efforts. Integration of
cultural beliefs: knowledge of values, customs, and practices is vital in
L&D. Modesty issues (males present, Asian cultures); Middle East
countries Pain expression:
quiet or vocal; some “keen” and wail. Depends on culture. Concept of hot and
cold foods & water. Pain: physiologic
manifestations : ↑ pulse & resp; dilated pupils, ↑ BP, &
muscle tension. Women often tighten skeletal muscles and lie motionless
→ muscular tension. Latent: pt is
usually happy & eager; establish rapport; offer fluids; comfort measures Active : feelings of helplessness, abandonment; enc
maintaining breath patterns; comfort rubs, keep couple informed Transition:
restless, tired, irritable; feels out of control; enc her to rest between
contractions; promote comfort; some women don’t want to be touched; ice
chips, privacy REFER TO TABLE
17-2: P 367 |
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Stage
2: patient may feel helpless, panicky, out of control; assist in pushing
efforts; encourage & praise; maintain privacy as woman desires Until
modern times, upright was the norm for giving birth. Maternal birthing
positions: Sitting on birthing stool; squatting; hands & knees. Work with
gravity. The
recumbent position (lithotomy) became the norm d/t increased convenience of
modern technology. Immediate
care of Newborn: Airway umbilical cord, Apgar, warmth, identification. Apgar
scores 0-2 for Heart rate, respiratory effort, muscle tone (look like a
frog), reflex irritability, & color. For possible 10 pts. Scored at at 1 & 5 mins. |
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While waiting for
signs of placental delivery, palpate the uterus for signs of uterine
relaxation & possible bleeding into uterine cavity. Oxytocics such as
Pitocin are given to promote contractions, involution, & ↓
bleeding. Sometimes Methergine or Hemabate are given. After placenta
delivered, physician or midwife inspect vagina & cervix and make
necessary repairs. Episiotomy is repaired. Monitor uterine
fundus firmness; vital signs: BP q 5
– 15 min (↑ - d/t preeclampsia or oxytocic drugs↓; temp – reflect blood loss); dehydration and
exhaustion; “shivers” ; inspect bloody vaginal discharge. Transfer to PP if: VS stable, no
bleeding, undistended bladder, firm fundus, & recovery from anesthesia
agents See Figure 17-9 for
method of palpating fundus. Enhancing
attachment: contact during 1st hour important; quiet state – baby
will interact with parents; ideal time to breast feed (Swedish study); darken
room if possible Precipitous
delivery: without physician or midwife;
precipitous labor defined as < 3 hrs, rapid birth |