Hormones, perineum, fetal circulation

  1. What hormone is known as the 'accelerator' in labour?
  2. What hormone is known as the 'clutch' in labour?
  3. What stimulates the release of oxytocin?
    • Suckling
    • Nipple/clitoral stimulation
    • Pressure on cervix
    • Perineal stretching
  4. What inhibits the release of oxytocin and how does this affect the process of labour?
    • Increased stress, fear or anxiety
    • Episiotomy (reduces stretching)
    • Induction/augmentation of labour, flooding oxytocin receptor sites, having opposite effect
    • This can cause prolonged labour, increased likelihood of post-partum haemorrhage and a reduction in nurturing behaviour between mother and baby
  5. What are beta-endorphins and what are their affects on the process of labour?
    Called the 'coping hormone' - natures pain reliever. Can modify perceptions of pain
  6. What hormone is known as the 'brake' in labour?
  7. What effect do catecholamines have on labour?
    Initiate 'fight or flight' response, causes shunt of blood from non-vital organs such as uterus. Causes lack of blood flow and oxygen to uterus which in turn causes more painful contractions and reduces oxygen available to fetus which can cause hypoxia
  8. Describe perineal tears and the layers involved.
    • First degree - perineal skin only
    • Second degree - perineal muscle and skin
    • Third degree - skin, muscle and partial or complete disruption of anal sphincter
    • Fourth degree - skin, muscle and complete disruption of external and internal anal sphinter
  9. What changes happen to the perineal muscles during the second stage of labour?
    • Levator ani muscles thin out and are displaced laterally
    • Superficial layer of pelvic floor stretch & transverse perineal muscles separate
    • Rectum compressed
    • Perineal body flattened
  10. What are the maternal needs for continuous fetal heart monitoring?
    • Maternal request
    • Pre-term labour (before 37 weeks)
    • Post-term labour (after 42 weeks)
    • Induction/augmentation of labour
    • Diabetes
    • Ante-partum haemorrhage
    • Maternal diabetes
    • Renal failure
    • Cardiac disease
    • PROM (over 24 hours ago)
    • Breech presentation
    • Previous section
  11. What are the fetal needs for continuous fetal heart monitoring?
    • Intra-uterine growth restriction (IUGR)
    • Oligohydramnios
    • Prematurity
    • Meconium stained liquor
    • Multiple pregnancy
    • Uterine infection
  12. What are the intrapartum needs for continuous fetal heart monitoring?
    • Epidural
    • Fresh meconium stained liquor
    • Vaginal bleeding in labour
    • Oxytocic augmentation of labour
    • Pyrexia - 38 degrees once or 37.5 degrees twice two hours apart
    • Abnormal fetal heart heard during labour or abnormal uterine activity
  13. What are the advantages of intermittent fetal heart monitoring?
    • Mother can hear
    • Does not limit mobility
    • Limited intervention
  14. What is a disadvantage of intermittent fetal heart monitoring?
    Unable to detect variability in fetal heart rate
  15. What is variability in FHM?
    Change in heart rate - normal is around 5-25 bpm from baseline rate
  16. What is 'cycling'?
    • Alternating of the fetus from sleep to activity stages.
    • 20-40 mins of reduced variability (<5 bpm) - 'rest phase'
    • 40-90 mins is non-reassuring
    • Over 90 mins is abnormal
  17. What is an acceleration?
    An increase of 15 or more bpm from baseline rate lasting for 15 seconds or longer
  18. What is a deceleration?
    • A reduction of 40 or more bpm for up to 60 secs. This usually occurs during a contraction and caused by cord compression and lack of oxygen. A healthy baby will return to baseline fairly quickly.
    • Atypical deceleration - lasting longer than 60 secs and slow return to baseline. Indicates fetal hypoxia.
  19. What does DR C BRAVADO stand for?
    • DR - Define Risk
    • C - Contractions
    • BRA - Baseline RAte
    • V - Variability
    • A - Accelerations
    • D - Decelerations
    • O - Overall
  20. Name the four temporary structures within the fetal heart.
    • Ductus venosus - shunts blood past liver
    • Foramen ovale - allows blood to shunt from right atrium to left atrium
    • Ductus arteriosus - shunts blood past pulmonary artery
    • Hypogastric arteries - take blood back to placenta via umbilical arteries
  21. What do the four temporary structures of the fetal heart form at or soon after birth?
    • Ductus venosus becomes ligamentum venosum
    • Foramen ovale becomes fossa ovalis
    • Ductus arteriosus becomes ligamentum arteriosum
    • Hypogastric arteries become lateral umbilical ligaments
Card Set
Hormones, perineum, fetal circulation
Hormones in labour