Answers
What are the indications of the onset of true labour? ✅Regular contractions - increase
in strength, length, freq
- Increase with walking, continue despite comfort and rest
- felt in low back, radiate to abd
Cervical changes
- cervix moving from posterior to anterior position
- cervix shortening and thinning (effacement)
- cervix dilation
May be accompanied by bloody show + rupture of the membranes
What physiologic changes occur in the mother in preparation for labour? ✅Increased
estrogen - activates uterus
Cervical ripening d/t increase in oxytocin, prostaglandin
Incr inflammation - activates cervix, uterus
Incr uterine oxytocin receptors
Incr central receptors for beta-endorphins (endogenous analgesia)
Incr in mammary and central oxytocin and prolactin receptors - promote breastfeeding,
attachment
What physiologic changes occur in the fetus in preparation for labour and delivery?
✅Pre-labour: lung maturation, development of oxytocin neuro-protective processes,
increase in epi/norepi receptors (protection from hypoxia)
In-labour: Preservation of blood supply to brain+heart via catecholamine surge -
promotes newborn breathing, energy+glucose production, and heat regulation
What role does oxytocin play in labour? ✅Produced by posterior pituitary
Ripens cervix, causes rhythmic contractions, reduces fear+stress and promotes calm,
promotes attachment
Promotes uterine contractions after birth - control PP bleeding
Released during breastfeeding to assist with milk ejection
What role do beta-endorphins play in labour? ✅Posterior pituitary
Analgesic + adaptive responses to stress and pain
What role do catecholamines play in labour? ✅Epinephrine, norepinephrine, dopamine
Hypothesis that E/NE inhibits labour when woman is in danger
Elevations in E/NE in late labour support newborn transition
Increase neonatal BP after birth
Responsible for initiation of thermogenesis
, What role does cortisol play in labour? ✅Stress hormone
Promotes contractions, increases central oxytocin effects on maternal adaptations &
attachment, enhances postpartum mood
Prepares fetus for birth, promotes lung maturation and clearance of lung fluid, supports
integrated transition of systems
What role does estrogen play in pregnancy? ✅Promotes growth of uterus, breasts
Increased blood flow to uterus
Smooth muscle relaxation
Activates and regulates other hormones of pregnancy
Define S&S of false labour ✅Irregular contractions, may stop and start
Contractions may be relieved with walking or rest, comfort measures
Felt in low back, abd above umbilicus
No cervical changes
What are the 5 P's of labour? ✅Passenger
Passage
Powers
Position
Psychological Factors
What does "Passenger" refer to? ✅Fetus - size, presentation, lie, attitude, position.
Placenta (possibly)
What does "Passage" refer to? ✅Maternal pelvis - pelvic bones, lower uterine
segment, cervix, pelvic floor muscles and vagina
What does "Powers" refer to? ✅Uterine contractions need to dilate the cervix and push
the fetus down and out of the passage
Labour contractions + voluntary bearing down
What does "Position" refer to? ✅Woman's position as she labours
What does "Psychological Factors" refer to? ✅Individual woman's strength, past hx,
ability to cope with pain, perception of pain, level of fear/anxiety, & values, beliefs and
intentions regarding labour and birth
What aspects are considered with regard to the passenger? ✅Size of the fetal head
Fetal presentation
Fetal lie
Fetal attitude
Fetal position
Engagement