Clinical: Labor and Delivery Flashcards

1
Q

3 stages of labor

A
  1. Cervical stage
  2. Pelvic stage
  3. Placental stage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

2 cervical changes during the first stage of labor

A
  • Effacement of the cervix
  • Dilatation of the cervix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Defnie effacement of the cervix

A

Shortening of the cervical canal into a paper-thin orifice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When does effacement occur?

A

As the muscle fibers near the internal os are pulled upward into the lower uterine segment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define dilatation of the cervix

A

Gradual widening of the cervical os

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Required cervical dilatation to allow the head of the average fetus at term to be able to pass

A

Approx 10 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When is the cervix completely dilated?

A

When the fetal head is able to descend past the remaining cervix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define the pelvic stage of delivery

A

Passage of the fetus through the maternal pelvis and expulsion of the fetus. Begins with complete dilation of the cervix and ends when the infant is delivered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How long should the pelvic stage of labor last in a nulliparous person with or without regional anesthesia

A

With = less than 3 hours

Without = less than 2 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How long should the pelvic stage of labor last in a multiparous patient with or without regional anesthesia

A

Without = less than 1 hour

With = less than 2 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define the third stage (placental) of labor

A

Separation and expulsion of the placenta. Begins with delivery of the infant and ends with the delivery of the placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

4 proposed theories to explain the mechanism of labor

A
  • Oxytocin stimulation
  • Fetal cortisol levels
  • Progesterone withdrawal
  • Prostaglandin release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the levels of oxytocin in maternal blood during labor

A

Early labor levels > onset of labor levels (no evidence of a sudden surge)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain how oxytocin may play a role in the spontaneous onset of labor

A

Oxytocin influence must rely on the presence of oxytocin receptors

  • Receptors are found in the non-pregnant uterus
  • 6-fold increase in receptors at 13 to 17 weeks’ gestations and an 80-fold increase at term
  • Increased number of oxytocin receptors amplifies the biologic effect of oxytocin and contractions intensify
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Give evidence as to how fetal cortisol levels may influence the spontaneous onset of labor

A

Disruption of hypothalamic-pituitary-adrenal axis or the absence of adrenal gland/function = prolonged gestation in humans and sheep

In sheep, infusion of cortisol or ACTH into a fetus with an intact adrenal gland causes premature labor, but not documentation of pre-labor surge in fetal cortisol to support this theory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Give evidence as to how progesterone withdrawal may cause labor

A
  • Rabbits = withdrawal of P –> prompt labor
  • Humans = no obvious decrease in maternal blood levels of P at term or in labor. However, P level at the placental site may decrease before onset of labor + increased E levels –> increased formation of gap junctions –> coupling of myometrial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

2 specific prostaglandins believed to be involved in spontaneous onset of labor

A

PGF 2(alpha) and PGE2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe how prostaglandin release may cause labor

A

Normal processes of layer lead to inflammation –> increased prostaglandin synthesis. Production in myometrial tissue may contribute to effectiveness of myometrial contractions during labor and may soften cervix independent of uterine activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

3 components of labor

A
  • Power - contractions
  • Passenger - fetus
  • Passage - pelvis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe early labor contractions

A
  • Occur every 5-10 min
  • Last for 30 - 45 sec
  • 20 - 30 mm Hg in intensity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe late labor contractions

A
  • Occur every 2 - 3 min
  • Last for 50 - 70 sec
  • 40 - 60 mm Hg pressure/intensity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

5 aspects of the fetus to be aware of during labor

A
  • Presentation
  • Position
  • Fetal lie
  • Fetal attitude or posture
  • Changes in the shape of the fetal head
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Define presentation in terms of the fetus

A

Indicates that portion of the fetus that overlies the pelvic inlet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How to determine the presentation of the fetus

A

Inspection and palpation of the maternal abdomen (Leopold’s maneuvers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

4 types of fetal presentation

A
  • Cephalic (95%)
  • Breech (3.5%)
  • Shoulder (0.4%)
  • Face (0.3%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

3 types of cephalic presentation

A
  • Vertex
  • Face
  • Brow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Define vertex cephalic presentation

A

Head is well flexed and the parietal bones are presenting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Define face cephalic presentation

A

Head is completely extended and face is presentin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Define brow cephalic presentation

A

Head is deflexed (or only partially extended)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Type of cephalic presentation that cannot deliver vaginally and why

A

Brow = largest antero-posterior diameter of the head is trying to megotiate through the maternal pelvis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

3 types of breech presentation

A
  • Frank breech
  • Complete breech
  • Incomplete or footling breech
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Define frank breech presentaiton

A

Thighs flexed, legs extended over anterior aspect of abdomen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Define complete breech presentation

A

Thighs flexed, legs flexed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Define incomplete or footling breech presentation

A

Knees and feet, one or both, are lowest and presenting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Define the Position with regards to the fetus

A

Relation of the fetal presenting part to the maternal pelvis

36
Q

4 markers for position of fetus

A
  • Occiput for vertex presentation
  • Sacrum for breech presentation
  • Mentum (chin) for face presentation
  • Acromion for sohulder presentation
37
Q

5 different positions for the designated fetal bony point

A

Relative to the maternal pelvis:

  • Right
  • Left
  • Anterior
  • Posterior
  • Transverse
38
Q

Define fetal lie

A

The relation of the long axis of fetus to that of mother (longitudinal [99%] or transverse or oblique)

39
Q

Describe the typical fetal attitude or posture

A
  • Ovoid mass in shape of uterine cavity
  • Back convex, head sharply flexed, thighs flexed over the abdomen, legs bent at knees, arches of feet rest on the anterior surface of the legs
  • Cephalic presentation = arms crossed over thorax or parallel to sides
40
Q

2 changes in the shape of the fetal head

A
  • Caput succadaneum
  • Molding
41
Q

Define caput succedaneum

A

In prolonged labor before complete cervical dilatation, the portion of the fetal head over the cervical os become edematous (usually only a few mm thick)

42
Q

Define molding in terms of changes in the shape of the fetal head

A

Changes from external compressive forces. Seldom overlapping of parietal bones (prevented by locking mechanism at the coronal and lambdoidal connections)

43
Q

4 methods of diagnosis of fetal presentation and position

A
  • Abdominal palpation
  • Vaginal exmaination
  • Auscultation
  • Ultrasound
44
Q

First Leopold maneuver

A

Palpate the fundus to determine the fetal pole present at the fundus

45
Q

Second Leopold maneuver

A

Palms pressed on either side of the abdomen (back + extremities)

46
Q

Third Leopold maneuver

A

Thumb and fingers of one hand, for presenting part

47
Q

Fourth Leopold maneuver

A

Face the mother`s feet, adn with the tips of the fingers of both hands, exert deep pressure in the direction of the axis of the pelvic inlet

48
Q

How to assess the degree of CPD through Leopold’s maneuvers

A

By evaluating the extent that the anterior portion of the fetal head overrides the symphysis pubis

49
Q

Define the pelvic planes

A

Hypothetical flat surfaces on the pelvis located at the brim, cavity and pelvic outlet

50
Q

Define the curve of Carus

A

Formed by an imaginary line that is drawn at the right angles of the pelvic planes

51
Q

4 shapes of the pelvis

A
  • Gynecoid
  • Android
  • Anthropoid
  • Platypelloid
52
Q

Define left occiput transverse (LOT) position

A
  • Smaller posterior fontanelle (triangle shaped with three sutures radiating from it) on left of maternal pelvis
  • Larger anterior fontanelle (diamond shaped with four sutures radiating from it) on opposite right side of maternal pelvis
53
Q

Define occiput anterior

A

Head enters the pelvis with the occiput anteriorly and rotated away from the transverse position

54
Q

Define occiput posterior

A

Where the fetus is facing up at delivery (often associated with a narrow forepelvis)

55
Q

7 sequential positional changes during the second stage of labor

A
  1. Engagement
  2. Descent
  3. Flexion
  4. Internal rotation
  5. Extension
  6. External rotation
  7. Expulsion
56
Q

Define engagement

A

The biperietal diameter of the fetal head, the greatest transverse diameter of the head in occiput presentations, passes through the pelvic inlet

57
Q

Lowest point of the presenting part in engagement

A

At the level of the ischial spines

NOTE: +3 = perineum

58
Q

4 forces that can bring about descent

A
  • Direct pressure of the amniotic fluid
  • Direct pressure of the fundus upon the breech with contractions
  • Bearing down efforts with the abdominal muscles
  • Extension and straightening of the fetal body
59
Q

Importance of flexion in second stage of labor

A

Chin brought into close contact with fetal throad –> smaller diameter of fetal head (biparietal diameter) to be presented to the pelvis

60
Q

When does internal rotation occur?

A

At the level of the ischial spines (0 station)

61
Q

Define internal rotation in second stage of labor

A

Gradual turning of the occiput anteriorly, such that the agittal suture runs antero-posteriorly as the fetal vertex descends through the plane of the midpelvis

62
Q

Define extension during the second stage of labor

A

Essential movement during birth process. When the sharply flexed fetal head meets the vulva, the occiput is brought in direct contact with the inferior margin of the symphysis

63
Q

2 reasons why extension occurs

A
  • Vulvar outlet is directed upward and forward, so must occur for head to pass through
  • Expulsive forces of the uterine contractions and the woman’s pushing, along with resistance of the pelvic floor = anterior extension of the vertex in direction of the vulvar opening
64
Q

Define external rotation (restitution)

A

Occiput returns to the oblique position from which it started and then to the transverse position (left or right). Corresponds to the rotation of the fetal body, bringing the shoulders into an antero-posterior diameter with the pelvic outlet

65
Q

Compare the rhythm, intervals and intensity of contractions of true vs. false labor

A

True vs. False

  • Rhythm = regular vs irregular
  • Intervals = gradually shorten vs. unchanged
  • Intensity = gradually increases vs. unchanged
66
Q

Compare the location and sedation effect on discomfort in true vs. false labor

A

True vs. False

  • Location = back and abdomen vs. lower abdomen
  • Sedation = no effect vs. usually relieved
67
Q

3 methods of confirming membrane rupture

A
  • Pooling
  • Nitrazine “dye” test
  • Ferning
68
Q

Describe the latent phase of labor

A

Uterine contractions can vary in intensity and frequency, but are sufficient to result in slow dilatoin and effacement of the cervix

69
Q

Define the active phase of labor

A

Progressive cervical dilation

70
Q

3 identifiable components of the active phase of labor

A
  • Acceleration phase
  • Linear phase of maximum slope
  • Deceleration phase
71
Q

5 elements accounted by the Bishop’s score

A
  • Cervical dilation
  • Cervical effacement
  • Cervical consistency
  • Cervical locations
  • Station of fetal vertex
72
Q

What does the Bishop’s score determine?

A

The favorability of the cervix and the risk of induction failure with an unripened cervis not be ripened

73
Q

2 hormonal agents used for cervical ripening

A
  • PGE1 (Misoprostol, aka cytotec)
  • PGE2 (Dinoprostone, aka Prepidil gel, and cervidil insert)
74
Q

Contraindication for hormonal cervical ripening

A

Prior C-section

75
Q

Mechanical method of cervical ripening

A

Foley bulb inserted through the cervix into uterine cavity and then filled with approx 30 cc of normal saline. Gentle tension applied to catherter so that bulb sits at level of internal os

76
Q

2 methods to augment labor

A
  • Amniotomy
  • Oxytocin administration
77
Q

2 risks of amniotomy

A
  • If done when head is not well applied to cervix, cord prolapse can result
  • If done too early in the labor process, can increase risk of chorioamnionitis
78
Q

When is C-section delivery indicated in the first stage of labor?

A

If progression of active labor does not occur with adequate contractions, an arrest of active phase is present

79
Q

Define Erb’s palsy

A

Injury to the brachial plexus due to excessive traction with extension of the infant’s neck during delivery

80
Q

Define episiotomy

A

Incision in the perineum that is either in the midline (median episiotomy) or begun in the midline, but directed laterally away from the rectum (mediolateral episiotomy)

81
Q

4 signs of placental separation

A
  • Uterus becomes globular and firm
  • Sudden gush of blood
  • Uterus rises in the abdomen. As the placenta, having been separated, passes down into the lower uterine segment and vagina, bulk pushes the uterus upward
  • Umbilic cord protrudes farther out of the vagina, indicating that the placenta has descended
82
Q

3 drugs to help uterus contract and decrease blood loss post-delivery

A
  • Intravenous or intramuscular oxytocin
  • Ergonovine
  • PGF2a
83
Q

Define first degree lacerations of the birth canal

A

Involvement of the fourchette, perineal skin and vaginal mucosa, but not the fascia and muscle

84
Q

Define second degree lacerations of the birth canal

A

Involvement of skin, mucosa, fascia and muscles of the perineal body, but not the anal sphincter

85
Q

Define third degree lacerations of the birth canal

A

Extension through the skin, mucosa, perineal body and involvement of the anal sphincter

86
Q

Define fourth degree lacerations of the birth canal

A

Extensions of the third-degree tear through the rectal mucosa to expose the lumen of the rectum