20) Parturition Flashcards
What is parturition?
Giving birth
What is spontaneous abortion?
Expulsion of products of conception before 24 weeks
What is pre-term birth?
Expulsion of products of conception between 24-36 completed weeks
What is term birth?
Expulsion of products of conception between 37-42 weeks
What is post-term birth and its clinical significance?
Expulsion of products of conception after 42 weeks
Pregnancy induce prior to this as fetus and mother at risk
Generally describe the 3 stages of labour:
1st: creation of birth canal
2nd: expulsion of fetus
3rd: expulsion of placenta and contraction of uterus
When does the uterus become palpable?
12 weeks
What is the lie of the fetus? (state the normal lie)
Its long axis in relationship to the long axis of the uterus Usually longitudinal (head or buttocks facing inlet)
What is the presentation of the fetus?
Give examples:
Part adjacent to pelvic inlet
Crown of head (cephalic), buttocks (breech)
How is pelvic inlet diameter increased during pregnancy?
Collagenases soften ligaments
What soft tissue structures need expanding to create the birth canal?
Cervix, vagina and perineum
Describe the process cervical ripening:
Reduction in collagen of cervix by increases in GAGs and hyaluronic acid
What triggers cervical ripening?
Prostaglandins
How does myometrium change in labour?
Hypertrophy
Increased forced of contraction due to greater intracellular calcium by action potentials from pacemaker
Describe Braxton-Hicks contractions:
Prepare uterus for labour, slightly high amplitude but less frequent than ‘real contractions’
