1. Physiological Adaptations
Normal
Labor and Delivery
Physiological Adaptations
Chapter 17
Presented by
Amie Bedgood

2. LABOR The process by which the products of conception are expelled
from the body

3. UTERINE CONTRACTIONS
Contraction - exhibits a wavelike pattern that begins slowly climbing (increment) to a peak (acme), and decreases (decrement)
Intensity - strength of uterine contraction
acme
Define the characteristics of uterine contractions. P. 338
The upper two thirds of the uterus produce contractions that push the fetus downward, while the lower one third is less active and reduces the resistance of movement downward. The characteristics of uterine contractions creates thickening of the upper myometrial muscle and a thinning of the lower uterine segment.
Decrement
Increment

4. UTERINE CONTRACTIONS acme Decrement Increment Duration Frequency
Interval
Frequency
Duration- from beginning of one contraction to the end of the same contraction
2. Define the following terms related to uterine contractions:
a. frequency
b. duration
c. intensity
d. interval
Frequency- from beginning of one contraction to the beginning of another contraction
Interval - resting time between contractions allows for placental
perfusion

5. Uterine Contraction - review

6. Assessment of Contraction
1. Subjective symptoms by woman
2. Palpation and timing by the nurse
3. Use of Electronic Fetal Monitor
(EFM)

7. Fill in the blank ! Length of a uterine contraction__________.
Strength of a uterine contraction is ___________.
The time from the beginning of one contraction to the beginning of the next contraction is _______.
The time that allows for placental perfusion is __.
The peak of a contraction is also known as ____.
When the biparietal diameter of the head passes through the pelvic inlet it is said to be ________.
Duration
Intensity
Frequency
Interval
Acme
engaged

8. CERVICAL ASSESSMENT
Dilation – is expressed in centimeters of the size of the cervical opening.
Full dilation = 10cm
Effacement – is estimated as a percentage of the amount the cervix has thinned.
Complete effacement = 100%
3. Define the following terms related to cervical changes during labor: p. 339
a. effacement
b. dilation
Dilation and effacement result from the downward movement of the fetus and the thinning of the lower uterine segment.

9. Myometrial Activity Effacement- thinning of the cervix (%)
Dilation – enlargement and widening of the os (cm)
4. How are cervical dilation and effacement measured? P. 339

10. Passenger
Essential
Factors in
Labor
Powers
Passageway
Psychological

11. THE
POWERS

12. Major Powers Involved Primary Force: Secondary Force:
Involuntary Uterine Contractions or
Muscular contractions which lead to dilation and effacement in the First Stage of Labor
Secondary Force:
Voluntary Uterine Contractions or
Abdominal muscles assist in the Second Stage of Labor with pushing. Increase intra-abdominal pressure to aid in expulsive forces
5. What are the primary and voluntary forces of labor? P.341
Discuss open glottis & closed glottis pushing.

13. THE
PASSAGEWAY

14. THE PELVIS
Determine if the pelvic cavity is of adequate size to allow for the passage of the full term infant
Optimum shaped pelvis is Gynecoid
See page 396 for pelvic shapes.
Pelvimetry is the term used to measure the pelvis.

15. THE PELVIS False Pelvis True Pelvis Represents
Supports the weight of the uterus
Shallow basin above the inlet or brim
True Pelvis
Represents
the bony
limits of the
birth canal
6. Differentiate between the terms true pelvis and false pelvis. p. 342 & 343

16. True Pelvis vs False Pelvis
Inlet - upper margin of symphysis pubis to the upper margin of sacrum
Midpelvis - level of the ischial spines
Outlet - Lower pubic bone to tip of coccyx This area is the smallest portion that the baby must travel through.
7. Differentiate between the inlet, the midpelvis, and the outlet of the true pelvis?

17. THE
PASSENGER
And
PPRESENTATION

18. Fetal Head
Because of its size and rigidity, the fetal head has a major impact on delivery.
The bones are not firmly united. There are sutures between the bones that allow them to overlap or MOLD to the birth canal.
Head also can rotate, flex, and extend
8. Compare the bones, suture lines and fontanels of the fetal head. What do the bones of the fetal head do to accommodate the birth canal? p. 344

19. Fetal Lie
Relationship of the long axis of the fetus to the long axis of the mother.
Longitudinal Lie Transverse Lie
9. Define the term "fetal lie". What is the difference between transverse lie and longitudinal lie. Which is the most favorable for a vaginal delivery? P. 341 & 344

20. True or False? The optimum lie of the fetus is the longitudinal lie.
A. True
B. False

21. Attitude Relationship of fetal body parts to each other Optimum
attitude is
flexion or
ovoid
10. What is fetal attitude? What is the normal fetal attitude? p. 334
Extention of the fetal parts such as head or arms straight would be abnormal attitude.

22. Fetal Presentation
The portion of the fetus that enters the pelvis first
Three Types:
Cephalic
Breech
Shoulder
11. Define the term "fetal presentation" and explain the difference between the following presentations: p. 344 & 345
cephalic presentation
Vertex
Military
Brow
Face
breech presentation

23. Reference Points of Presentation Cephalic = Head
Vertex, Military, Brow, Face
Breech = Buttock or Foot
Frank, Full, Footling
Shoulder = Transverse lie
p. 345
Vertex – most common presentation with fetal head flexed. Favorable position for labor and delivery as smallest diameter of fetal head is presenting.
Military – the fetal head is in a neutral position, head is neither flexed or extended.
Brow – the fetal head is partially extended.
Face – The head is fully extended and the fetal occiput is near the maternal spine.
Frank – Buttock is presenting with the fetal legs extended across the abdomen towards the shoulder.
Full – (Complete) Buttock is presenting with hips and legs flexed.
Footling – one or both feet present.
Shoulder – is considered transverse lie and C/S is necessary

24. Cephalic Presentations

25. Breech Presentations

26. Position
12. What is fetal position? Explain the position indicated by the letters: p. 345
LOA
ROA
LOP
ROP
Fetal position describes the location of the fixed reference point on the presenting part in relation to the four quadrants of the maternal pelvis.
R= right, L= left, O= occiput, A=anterior, P=posterior.
13. What is the reference point for a vertex presentation? Occiput
14. What is the reference point for a breech presentation? Sacrum

27. Position
Relationship of the Fetal Presenting Part to the Maternal Pelvis
Steps:
1. Determine the Presenting Part
2. Divide the mothers pelvis into 4 imaginary quadrants A 12 R L 9 3 6 P

28. Test Yourself !
What is the reference point of a cephalic presentation when the head is fully flexed?
A. occiput
B. mentum
C. frontal
d. sagittal A
Mentum = chin

29. Test Yourself
Overlapping of the fetal skull to facilitate its passage through the bony pelvis is ___________.
Relationship of fetal body parts to each other is_____________.
Head first presentation is_________________.
Relationship of the fetal spine to the maternal spine is ________________.
Term that refers to the part of the fetus that enters the pelvic inlet first is _____________.
Molding
Attitude
Cephalic
Lie
Presentation

30. THE
PSYCHOLOGICAL
15. How does anxiety, fear, and fatigue physiologically affect the process of labor? P. 347 & 348

31. BREAK THE CYCLE ! FEAR TENSION PAIN
15. How does anxiety, fear, and fatigue physiologically affect the process of labor? P. 347 & 348
Anxiety, fear, tension, or fatigue decreases a woman’s ability to cope with pain in labor. Maternal catecholamines are secreted in response and can inhibit uterine contractility and placenta blood flow. Therefore, a nurse’s supportive attitude can strengthen the woman positive psychological control during labor and enhances the birthing process.
PAIN

32. CAUSES OF LABOR Increase in Estrogen Decrease in Progesterone
Page 404.
Progesterone relaxes smooth muscles – interferes with the conduction of impulses from one dell to the next. It exerts a quieting effect on the uterus during pregnancy. Towards the end of gestation, biochemical changes cause a decrease in progesterone. A decrease in progesterone allows for an increase affect of estrogen.
Estrogen increase enhancing uterine sensitivity to substances such as prostaglandins from the fetal membranes and oxytocin from the maternal posterior pituitary gland.
Prostaglandin stimulate uterine contractions.
Connective tissue loosens to permit softening, thinning, and eventual opening of the cervix.
High levels of
Prostaglandins
Degeneration of
Placenta
Over-distention of
Uterus

33. Premonitory Signs of Labor
The impending signs
that take place the last
several weeks of
pregnancy or even the
last several days
Warning signs that the woman may experience indicating that labor is near.

34. Premonitory Signs of Labor
LIGHTENING
FALSE LABOR PAIN (Braxton Hicks)
SHOW
Rupture of Membranes (ROM)
BACKACHE
DIARRHEA
SUDDEN INCREASE IN ENERGY
Lightening – “dropping” the fetus settles into the pelvic inlet, the woman can usually breath easier. Can result in leg cramps or pain due to pressure on the nerves that pass through the obturator foramen in the pelvis, increase pelvic & bladder pressure, venous stasis leading to edema in the lower extremities, increased vaginal secretions resulting from congestion of the vaginal mucosa.
Braxton Hick’s – irregular, intermittent contractions that have been occurring throughout the pregnancy. May be uncomfortable and exhausting.
Bloody Show – blood tinge mocusy discharge resulting from exposed capillaries as the cervix soften and effaces.
Rupture of membranes – amniotic membrane ruptures before the onset of labor occurs in approximately 12 % of women and labor usually ensues within 24 hours.

35. True vs False Labor TRUE LABOR FALSE LABOR Contractions are:
* Regular
* Increase in intensity and
duration with walking
* Felt in lower back,
radiating to lower portion
of abdomen
Bloody show
Dilation and effacement
Fetus usually engaged
FALSE LABOR
Contractions are:
* Irregular
* No change or decrease
with walking
* Contractions felt in
abdomen above
umbilicus:
Braxton Hicks
No change in cervix
Fetus is ballotable

36. Mechanisms of Labor/ Cardinal Movements
Descent
Flexion
Internal Rotation
Extension
External Rotation
25. Explain the positional changes /cardinal movements of stage 2 and why they occur in this order?
Expulsion

37. Station- degree that the presenting part has descended into the pelvis
in relationship to ischial spines.
Goal: Move from
– to + stations
9. What is station? How is station determined and measured? Does the station need to be a + or – for delivery?

38. Engagement
Descent of the fetal presenting part in relation to the ischial spines of the maternal pelvis = 0 station.

39. Engagement
Engagement
-largest diameter of presenting part has passed through the pelvic inlet
Assessed during
vaginal exam
Ballotable
8. What is engagement? How is it determined?
Engaged

40. Phases and Stages of Labor
Stage 1: cm.
Phase 1 - Latent - dilate cm.
Phase 2 - Active - dilate cm.
Phase 3 - Transition - dilate cm
Stage 2: From complete dilation and
effacement to delivery of the baby
Stage 3: From delivery of baby to the
delivery of the placenta
Stage 4: the first hour after delivery
21. Define the first stage of labor. P. 349.
22. What are the three phases of the first stage of labor?
23. What are the characteristics of each of each of these three phases in terms of cervical dilation, uterine contractions, and maternal behavior?
Labor Curve or Friedman curve is used to determine whether labor is progressing at the expected rate.

41. Signs of Second Stage of Labor
Complete dilatation of cervix
Urge to bear down
Perineum begins to bulge, flatten and move anteriorly
Increase in bloody show
Rectal pressure
Labia begins to part with each contraction
24. Define the second stage of labor and the maternal behavior associated with this stage. P. 349.

42. Signs of Stage Three of Labor
Globular
Shape of Uterus
Fundus Rise in Abdomen
Sudden Gush of Blood
Protrusion of Umbilical cord
25. What is the third stage of labor and what are the signs that indicate placental separation? P. 349.
Delivery of the placenta

43. Fourth Stage of Labor
Recovery period after delivery and bonding with the newborn.
Last from 1- 4 hours.
26. Define the fourth stage of labor and the maternal behavior associated with this stage. P. 349.
Recovery 1-4 hours after delivery.

44. Nursing Assessment and Interventions during Labor and Birth.
Nursing Care
Nursing Assessment and Interventions during Labor and Birth.

45. Technique for Assessing Fetal Presentation and Position
Abdominal Palpation/Leopold’s Maneuver
Standing on the right side, face the woman and palpate with the palms of the hands.
Step 1 - Start at upper fundus and palpate for the head or buttocks
Step 2 - Go down each side and locate back
Step 3 - Gently grasp lower portion of uterus and feel for the head or buttock
Step 4 - Turn and face the woman feet, using both hands palpate lower abd. for cephalic prominence or brow.

46. Ausculation Assess for the area of greatest intensity of the FHR.
Usually best heard at the fetal back

47. True or False ?
If the fetal heart tones (FHT’s) are heard loudest (PMI) in the patient’s upper right quadrant of her abdomen, the fetus would be assessed for a breech presentation.
A. True
B. False
true

48. Amniotic Membranes Intact Ruptured Color Amount SROM AROM Clear Yellow
Meconium
Amount

49. Vaginal Examination Presentation – presenting part (head/buttock)
Position – fetal head (OA, OP etc.)
Condition of Membranes – ruptured or intact
Dilation - enlargement & widening of os (cm)
Effacement – thinning of the cervix (%)

50. Vaginal Examination – cont’d
Station- degree that the presenting part has descended into the pelvis. Relationship to ischial spines (-, 0, +)
Engagement -largest diameter of presenting part has passed through the pelvic inlet

51. Try this ! When the cervical os widens or opens it is said to________.
The level of the ________ _________ (bony structure) is station zero.
The most common type of pelvis for a woman ____________.
When the cervix shortens and thins is _______________.
For delivery to occur, the fetus must accommodate to this rigid passageway______________.
Dialating
Ischial spines
Gynacoid
Effacement
Pelvic outlet

52. Duration of Labor Resistance of the Cervix
Presentation and position of the fetus,
The woman’s pelvis
Preparation and relaxation of the mother
Primigravida - up to 22 hrs; average 12 1/2 hrs
Multigravida hrs; average 10 hrs.
Read this section Duration of labor is depended upon several factors.

53. The End
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