Labour and Delivery Flashcards
Outline the physiology of labor
- Fetus HPA axis ↑ (↑ CRH, ↑ ACTH, ↑ glucocorticoids + androgens)
- This decreases progesterone (less inhibition of myometrial contractions/sensation) and increases oestrogen (more prostaglandins)
- These prostaglandins cause sofening of the cervix, and increased sensitivity to oxytocin
- In response to stretching of the cervix/vagina by the baby’s head, oxytocin is released, which is picked up by the uterus and contractions begin
Define labor (in the medical sense)
Onset of painful, regular contractions with progressive cervical effacement (WIT?) and dilation.
Define the three stages of labour
First: onset -> full dilation (??cm)
Second: full dilation -> birth
Third: birth -> delivery of placenta
How should a woman’s contractions change throughout labour?
They should become progressively longer and more intense, with decreasing time between (down to around ~2/3 minutes towards the end)
What does a cardiotocograph represent?
- Fetal heartbeat & duration of uterine contractions
- Provides real-time updates on both
Describe monitoring/respective freq during pregnancy
- Every 15min: mum and baby’s heart rate
- Every 30min: palpate strength of contractions
- Every 60min: Mum’s BP and temp
- Every 4 hours: vaginal exam
What are we checking for on a vaginal exam during the first stage of childbirth?
- Check liquor (what is this? what do we expect)
- Position of baby
- Station (WIT?)
- Caput (WIT?)
- Moulding (WIT?)
- Cervical dilation
What is meant by station, caput, and moulding during pregnancy?
- Station: “altitude” of head relative to ischial spines (negative is superior, positive is inferior). Imagine a series of stations along the female anatomy, like everest.
- Caput: swelling/oedema of scalp during birth (why would we assess for this?)
- Moulding: overlap of skull bones as head passes through the birth canal
True or false: CTG tells us foetal heart rate, and strength/duration of uterine contractions
- False
- It only shows duration and foetal heart rate (NOT strength!)
Why is it uncommon to use general anaesthetic in labour?
- Higher rates of post-partum haemorrhage
- GA drugs pass through placenta (baby is also asleep)
- Intubation is harder in pregnancy (?airway swelling)
What kinds of analgesics can we use during labour (first stage of pregnancy)? Consider pharmacological or otherwise
- Hot packs (what contraindicates this? Why?)
- Movement/changing position
- Water immersion
- N2O2 gas (N. Oxide)
- Fentanyl
- Rarely IV analgesia
- Epidural/spinal block (what’s the difference?)
What are the four Ps to consider during the second stage of childbirth?
- Power (how hard are contractions?)
- Passage (how big is the pelvic canal?)
- Passenger (how big is the baby?)
- Pysche (mindset of mother; how are they coping?)
What are the signs of separation of the placenta from the uterine lining?
- Uterine contraction
- Separation bleed
- Apparent lengthening of the cord
- Bulging of labia
Describe the two kinds of placental delivery (?timeframes)
Active (normal is less than 30min):
- Oxytocin given w/ anterior shoulder
- Once contracted, controlled cord traction
Physiological (normal is less than 60mins):
- Placenta is passed spontaneously
- Can assist by getting baby to latch on to breast
What is labor dystocia? What are some ways we can manage it?
- Prolonged/abnormal progression of labour
- (1st: do dilation >4hrs; 2nd: >3hrs first birth, >2 for P1+)
- Can be managed through analgesia/observation, induction of labour (membrane rupture), oxytocin infusion, or operative birth
What are some manual ways to assist in delivery of a child?
- Manual rotation
- Suction cup (vacuum)
- Forceps
- Episiotomy (where is this cut made?)
Risks of vacuum/forceps during delivery
Both: cephalohematoma, increased risk of perineal trauma/episiotomy extension (hurts mum and baby)
Vacuum: Subgaleal haemorrhage
Forceps: facial/brachial palsy, skull fractures
Indications: fetal distress, maternal exhaustion, failure to progress to second stage
What are non-elective indications for caesarean section?
- Fetal distress
- Cord prolapse
- Malpresentation
- Antepartum/intrapartum haemorrhage
- Maternal effort contraindicated (e.g. cerebral aneurysm)
Elective indications for caesarean
- Placenta praevia
- True cephalopelvic disproportoin
- Severe growth restriction
- Twins
- Request
Risk factors/causes/Fx of obstructed labor
- Risks: pelvic fractures, fetal macrosomia
- Causes: malpresentation (WIT?), cephalopelvic disproportion
- Fx: maternal haematuria, failing to descend, caput/moulding, abnormal labor progress
What is fetal distress? What causes it? How do we treat it?
- It’s when the baby is deprived or suspected to be deprived of oxygen during labour
- Can be caused by cord compression, maternal hypotension, hyperstimulation
- Managed with fluids (through umbilical vein), position change, surgical delivery, or anti-tocolytics (What are these?)
Quantify post-partum haemorrhage? What are the 4 Ts of post-partum haemorrhage?
Definition ~500mL blood loss during vaginal, 1L Caesarean
- Tone (no tone; give manual massage + oxytocin)
- Trauma (sew up, or may need surgery)
- Tissue (treat w/ uterine evacuation)
- Thrombin (DIC; replace coagulation factors)
What is the most common cause of uterine inversion? How do we treat it?
- Most often cuased by cord traction before uterus is contracted
- Treat by pushing it back in, and leaving hand in until the uterus has contracted
What are the four degrees of perineal tear?
First: injury of vagina/vulva only
Second: perineum too, but not anal sphincter
Third: includes anal sphincter
Fourth: also includes anal/rectal mucosa
List common complications of labour
- Obstructed labour
- Fetal distress
- PPH (WIT?)
- Cord prolapse
- Shoudler dystocia
- Uterine inversion
- Perineal tears
True or false: face presentation is an indication for caesarean section
True. Almost all such babies are delivered this way.
Rx for pre-term birth
- Antibiotics (prevent infection)
- Steroids (fetal lung maturation)
Latent vs active labour
Latent: up to 4cm
Advice: 4-10cm
Mother is only actively pushing in active labour
Passive vs active delivery
Passive: not actively pushing (such as initial epidural descent)
Active: repetitive valsalva menouevre
What are Braxton Hicks contractions? What are their features that help us differentiate from actual labour?
- Body “practicing” for true labour; uterine contractions
- Does not increase in freq, duration, intensity
- No cervical changes
Why is skin to skin contact after birth important?
- Increased chance of normal breastfeeding
- Maintains neonatal BGL + vitals
- Improved maternal mental health
Do we clamp the umbilical cord straight away? Why?
- Not any more (I was ahead of the curve)
- Leave for 1-3 minutes
- Shown to decrease chances of iron deficiency and anaemia
