Parturition - Phases Flashcards Preview

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Flashcards in Parturition - Phases Deck (11):
1

Phases

  • Name of phase
  • General description

  • Phase 1
    • Quiescence
    • Prelude to parturition
  • Phase 2
    • Activation
    • Preparation for labor
  • Phase 3
    • Stimulation
    • Process of labor
  • Phase 3
    • Involution
    • Parturient recovery

 

Memory aid:

  • QuASI

2

Phase 1

  • Name
  • General description
  • When
  • Uterus
  • Cervix

  • Name
    • Quiescence
  • General description
    • Prelude to parturition
  • When
    • Begins even before implantation
  • Uterus
    • Contractile unresponsiveness
    • Braxton-Hicks contractions may be felt
  • Cervix
    • Maintenance of cervical structural integrity despite cervical softening, increased vascularity and stromal hypertophy

3

Phase 2

  • Name
  • General description
  • When
  • Uterus
  • Cervix

  • Name
    • Activation
  • General description
    • Preparation for labor
  • When
    • During the last 6-8 weeks of pregnancy
  • Uterus
    • Myometrial unresponsiveness suspended
    • Formation of LUS → lightening
  • Cervix
    • Cervical ripening, effacement and loss of structural integrity

4

Myometrial changes in the activation phase is attributable to:

Expression of contraction-associated proteins

  • ↑ uterine irritability
  • ↑ responsiveness to uteronins
    • oxytoxin receptor
    • prostaglandin F
    • connexin 43

5

Treatment to:

  • Prevent premature cervical ripening
  • Promote cervical ripening

  • Prevent premature cervical ripening
    • No therapies
  • Promote cervical ripening
    • Prostaglandin E2 (PGE2) and PGF
    • Progesterone antagonist

6

Prostaglandin MOA

Modify extracellular matrix structure to aid ripening

7

Phase 3

  • Name
  • General description
  • When
  • Uterus
  • Cervix

  • Name
    • Stimulation phase
  • General description
    • Processes of labor
  • When
    • Active labor
  • Uterus
    • Uterine contractions
  • Cervix
    • Cervical dilation

 

Note: It also includes fetal and placental expulsion (3 stages of labor)

8

Phase 4

  • Name
  • General description
  • Uterus
  • Cervix

  • Name
    • Involution phase
  • General description
    • Parturient recovery (puerperium)
  • Uterus
    • Uterine involution
  • Cervix
    • Cervical repair

9

Of the 4 phases of parturition, phase 2 is characterized by which of the following?

  1. Uterine activation, cervical ripening
  2. Uterine quiescence, cervical softening
  3. Uterine involution, cervical remodelling
  4. Uterine contraction, cervical dilatation

Answer: 1

  • Uterine activation, cervical ripening

 

Rationale:

  • 2 - phase 1
  • 3 - stage 4
  • 4 - stage 3

10

Collagen changes in phase 1 vs phase 2

  • Phase 1 (softening)
    • altered collagen processing and the number/type of covalent cross-links between collagen triple helices
    • reduction in cross-links between newly synthesized collagen monomers
  • Phase 2 (ripening)
    • fibril diameter increased
    • space between fibrils increased and disorganized
    • dispersion of collagen fibrils resulting to loss of tissue integrity and increased compliance

11

Phase of parturition that corresponds to the clinical stages of labor

Phase 3