Normal Labor Flashcards
Predisposing factors for Transverse Lie
Multiparity
Placenta previa
Hydramnios
Uterine anomalies
Cephalic presentations
Vertex/Occiput (Posterior Fontanel)
Sinciput (Ant Fontanel)
Brow
Face
Predisposing factors for face presentation
Fetal malformation (Anencephaly)
Cord Coil
High parity
Breech Presentation
Frank
Complete
Footling
Incidence of Breech
Decreases with AOG 28 wks = 25% 30 wks = 17% 32 wks = 11% Term = 3%
Landmarks in identifying fetal position: Vertex
Occiput
Landmarks in identifying fetal position: Face
Mentum
Landmarks in identifying fetal position: Breech
Sacrum
Landmarks in identifying fetal position: Shoulder
Scapula
What is Caput Succedaneum?
It is a local edema.
What is Molding?
It refers to bony changes in the fetal head which results in shortened suboccipitobregmatic diameter
Incidence and internal rotation: Left Occiput Transverse
40%, 90 degrees
Incidence and internal rotation: Right Occiput Transverse
20%, 90 degrees
Incidence and internal rotation: Occiput Anterior
20%, 45 degrees
Incidence and internal rotation: Occiput posterior
20%, 135 degrees
What are the phases of Parturition
Phase 1: Quiescence
Phase 2: Activation
Phase 3: Stimulation
Phase 4: Involution
Describe the events during the phase 1 of labor
Preludes to parturition (6-10 days post fertilization)
Impt events: Contractile unresponsiveness, cervical softening
*Braxton-Hicks contractions may be felt
What happens during cervical softening?
- Increased compliance yet maintaining structural integrity
- Increased vascularity
- Stromal hypertrophy
- Glandular hypertrophy and hyperplasia
Describe the events during the phase 2 of labor
Preparation for labor
Impt events: Uterine preparedness for labor (myometrial unresponsiveness suspended, increasing oxytocin receptors), Cervical ripening, effacement and loss of structural integrity (collagen fibril diameter decrease then increase), formation of the lower uterine segment (lightening)
Describe the events during the phase 3 of labor
active Labor
Impt events: Uterine contraction, cervical dilatation, fetal and placental expulsion
Describe the events during the phase 4 of labor
Puerperium
Impt events: Uterine involution, cervical repair, breastfeeding
Definition of Labor
Uterine contractions that bring about demonstrable effacement and dilatation of the cervix
What are the three stages of labor?
Stage 1: Painful REGULAR contractions to cervical dilatation
Stage 2: Starts with 10cm cervical dilatation to fetal delivery
Stage 3: Delivery of placenta and membranes
Reasons why contractions are painful
- Hypoxia of the myometrium
- Compression of the nerve ganglia
- Cervical stretching during dilatation
- Stretching of peritoneum overlying fundus
What is Ferguson reflex?
Mechanical stretching of the cervix enhances uterine activity
How does a physiological retraction ring during 1st stage of labor?
Distinct upper and lower uterine segment
How does a pathological retraction ring (of Bandl) during 1st stage of labor?
Thinning of the lower uterine segment is extreme in obstructed labor
What happens when there is an elongation of the ovoid uterus?
Increases fetal axis pressure and straigthens the fetal vertebral column
During the second stage of labor, how long do uterine contractions averages?
Ave: 1 min (30-90 seconds)
Interva between is 1 minute or less
Most important force in fetal expulsion produced is
Maternal intraabdominal pressure
What is a station?
It describes the descent of the fetal BPD in relation to a line drawn between two maternal ischial spines
what are the cardinal movements?
Engagement Descent Flexion Internal Rotation Extension External Rotation/Restitution Expulsion
With nulligravids, when does the engagement of the neonate occurs - before or after labor?
Before
What are the forces that help in the descent of a neonate?
- Pressure of amniotic fluid
- Pressure of fundal contractions
- Maternal Effort
- Straightening of fetal body
What are the opposing forces that help in the extension of a neonate?
- Pressure of fundal contractions
2. Resistance of pelvic floor
What are the functional divisions of labor? Explain each.
- Preparatory - latent and acceleration phase of cervical dilatation; this can be arrested by sedation and conduction analgesia
- Dilatational - phase of max slope; commonly occurs after 6cm dilatation; not affected by sedation
- Pelvic - deceleration; cardinal movements are seen
Explain the latent phase of cervical dilatation
- Duration is more variable and sensitive to extraneous factors
- Ends once dilatation of 3-5 cm is reached
- Prolonged disorders
Explain the active phase of cervical dilatation
- Acceleration - predictive outcome
- Phase of max slope- reflective overall eficiency of the contractile mechanism; usually descent in nulliparas occur here
- Deceleration
Signs of placental separation
- Calkin’s sign - uterus becomes globular and firmer
- Sudden gush of blood
- Uterus rises in the abdomen
- Lengthening of the umbilical cord
Mechanism of placental expulsion: Schultze Mechanism
Blood from the placental site pours INTO the membrane sac and does not escape externally until after extrusion of the placenta; Retroplacental hematoma follows the placenta or is found within the inverted sac
Mechanism of placental expulsion: Duncan Mechanism
Placenta separates first at the periphery and the blood collects BETWEEN the membranes anf the uterine wall and escape from the vagina; placenta DESCENDS SIDEWAYS, maternal surface appears first
In transverse lie, Leopold Maneuver 1 is:
a. Cephalic
b. Breech
c. Small fetal parts
d. Empty
C
In anterior asynclitism:
a. If the coronal suture approaches the sacral promontory, more of the anterior parietal bone presents itself to the examining fingers
b. If the sagittal suture approaches the sacral promontory, more of the anterior parietal bone presents itself to the examining fingers
c. If the sagittal suture approaches the sacral promontory, more of the posterior parietal bone presents itself to the examining fingers
d. If the coronal suture approaches the sacral promontory, more of the posterior parietal bone presents itself to the examining fingers
B
This movement turns the occiput gradually away from the transverse axis: *
a. Engagement
b. Flexion
c. External rotation
d. Internal rotation
D
This commences with the deceleration phase of cervical dilation; this is also where cardinal movements of labor occur
a. Deceleration phase
b. Pelvic division
c. Acceleration phase
d. Dilatational division
B
In this maneuver, the examiner faces the mother’s feet, and the fingertips of both hands are positioned on either side of the presenting part
a. Leopold Maneuver 4
b. Leopold Maneuver 2
c. Leopold Maneuver 1
d. Leopold Maneuver 3
A
Prolonged latent phase in multiparas is defined as *
a. 12 hours in latent phase
b. 20 hours in latent phase
c. 14 hours in latent phase
d. 16 hours in latent phase
C
Second stage of labor is defined as: *
a. Cervical dilatation to expulsion of fetus
b. None of the aforementioned
c. Expulsion of fetus to expulsion of placenta
d. Regular contraction to full cervical dilatation
B
This refers to the relationship of an arbitrarily chosen portion of the fetal presenting part to the right or left side of the birth canal a. Fetal Attitude b. Fetal Position c, Fetal Presentation d. Fetal Lie
B
