Normal labour Flashcards
What are the definitions for moulding
0
+1
+2
+3
Def of moulding
0 = bones are separated and sutures can be easily felt
+1 = Bones are touching each other
+2 = Bones are overlapping but can be reduced with finger pressure
+3 = bones are over lapping and can’t be easily reduced
Discuss 5ths palpable and corresponding station
5/5 - Station -4/-5
4/5 - Station -3
3/5 - Station -2
2/5 - Station -1
1/5 - Station at spines
0/5 - Below spines
Discuss the stages of labour
-Definition of latent phase
-Average duration of latent phase for a nullip
-Average duration of latent phase for a multip
-Definition of active phase
-Average duration of active phase in a nulip
-Average duration of active phase in a multip
-Slow labour definition
- Definition of latent phase
-Painful contractions with some cervical change including effacement and dilation up to <4cm - Average length in nulip - 1.7 - 15 hrs
- Average length in multip - not studies
- Definition of active phase
-Strong regular contractions with progressive dilation from 5cm - Average time of active phase in nulip
-10th centile 0.9cm/hr
-1.0 - 19.4
-Average 8 hrs - Average duration in a multip
-10th centile 1.2cm/hr
-Average 5hrs
-0.5-14.9 hrs - Slow labour def
-Less than 2cm dilation in 4 hrs once in active labour
Discuss second stage of labour
-Definition of passive second stage
-Definition of active second stage
-Duration of active second stage in nulips
-Duration of active second stage in multips
- Definition
-Full dilation prior to or in the absence of involuntary expulsive contractions - Definition of active second stage - any of these
-When the baby is visible
-There are expulsive contractions
-There is active pushing with maternal effort - Duration of active second stage in nulips
-suspect delay if >2hrs
-Average 54 mins - Duration of active second stage in multips
-Suspect delays if >1hr
-Average 18mins
Discuss third stage of labour
-Definition
-Management approaches - active
-Management approach - physiological
-When action needs to be taken
- Definition
-From time of birth of baby until time placenta is delivered - Management - active third stage
-Routine oxytocin
-Delayed cord clamping
-CCT after signs of separation - Management - physiological
-No routine use of uterotonics
-No clamping of cord till pulsation has stopped
-2 times risk of PPH and transfusion
-Delivery by maternal effort - When should action be taken
-30mins if not delivered involve obstetrics
-60mins if not delivered to OT
Describe the mechanics of delivery (7 steps)
- Engagement of the presenting part - usually transverse
- Descent of the presenting part t below the spines
- Flexion of the head against the pelvic floor
- Internal rotation - head to OA and shoulders transverse
- Extension - of the fetal head under the pubic arch
- Restitution of the head so that shoulders are AP
- Delivery of shoulders
Describe labour cares
-Care in first stage (10 points)
- Initial assessment
-Determine level of risk of pregnancy to guide monitoring and location of birth - One on one care
-Undertake once in established labour
-Reduces rate of CS, operative vaginal delivery, use of analgesia, shortens duration of labour, improved apgar scores
3.Fetal monitoring
- intermittent ascultation or continuous CTG - Maternal obs - hrly
- Monitor progress
- 4hrly VE. (RANZCOG) - Monitor uterine activity - palp, toco, intrauterine pressure transducer
- Regular bladder emptying
- Encourage mobilisation
- Provide analgesia
- Routine amniotomy and oxytocin not recommended - No diff in CS, SVB, instrumental, epidural. No diff in length of first stage (RANZCOG)
Discuss care in labour
-Second stage
- Monitoring
Offer VE every hr in multigravid and every 2 hrs in primigravida - Pushing
-Encourage pushing once fully dilated and woman has urge to push or head at perineum
-Avoid sustained valsalva is associated with adverse fetal and maternal effects
-Lower fetal O2
-More frequent occurance of fetal heart rate pattern
-Delayed recovery of fetal heart
-Increased perineal trauma
-Lower apgar scores
-Delaying active pushing reduces forceps, CS
Discuss positioning for delivery
-Benefits of upright/lateral position (6)
-Benefits of supine (2)
- Benefits of upright position
-Reduction in duration of second stage
-Reduction in assisted deliveries and CS
-Reduction in abnormal CTG
-Less episitomies
-Less painful
-Reduction of labour by 80 mins - Benefits of supine
-Reduction in perineal trauma
-Less blood loss
Discuss perineal management
-Methods to decrease trauma (4)
-Role of episiotomy (2)
-When should episiotomy be considered (4)
- Methods to reduce trauma
-Encourage woman to stop pushing as baby is crowning
-Use hands on/hands poised approach to flex head and control delivery
-Use warm compress - reduces perineal tears (Cochrane review)
-Deliver baby’s shoulders one at a time
-Perineal care bundle reduces severe perineal trauma and should be offered - Role of Episiotomy
-Routine episiotomy not recommended
-Epis not recommended even with previous severe perineal trauma
-Epis can reduce posterior trauma but increase anterior trauma - Consider episiotomy when:
-Soft tissue dystocia
-Requirement to accelerate birth
-Facilitate operative delivery
-Hx of GFM
Discuss the anatomy of the pelvis
-Boundaries of the pelvic inlet (3)
-Boundaries of the pelvic outlet (4)
-Types of pelvis (4)
- Boundaries of the pelvic inlet
-Anterior - symphysis pubis
-Posteriorly - sacral promontory, ala of the sacrum
-Laterally - Ileopectineal line - Boundaries of the pelvic outlet
-Anterior - symphysis pubis
-Posteriorly - tip of coccyx
-Anterolaterally - ischiopubic ramus
-Posteriolaterally - sacrotuberous ligament - Types of pelvis
-Android - narrow midcavity and pubic arch
-Anthropooid
-Gynecoid
-Platypelloid
Discuss changes to the uterus
-Method of enlargement (1)
-Muscle composition (2)
-Types of uterine activity (2)
-Innervation
- Method of enlargement
Smooth muscle hypertrophy from 50g to 950g - Muscle composition
Interdigitating smooth muscle fibres making up one muscle
Consists of two layers
-Inner layer fibres are circular
-Outer layer fibres are longitudinal - Types of uterine activity
-Braxton-Hicks - low amplitude, long duration
-Contractions - high amplitude, short duration - Innervation
-Sympathetic supply from hypogastric nerve
-Noradrenalin./adrenalin acts on alpha receptors - contractions
-Noradrenalin/adrenalin acts on beta receptors - relaxation (Beta agonists cause relaxation - salbutamol)
Discuss mechanics of uterine contractions
-Uterine activity inhibitors (5)
-Uterine activity stimulators (5)
-Mechanics of a uterine contraction
- Uterine activity inhibitors
-Uterine quiescence is maintained throughout pregnancy
-Progesterone - down regulates gap junctions
-Nitric oxide
-Beta-adrenergic stimulation
-Relaxin
-Hypoxia and acidosis - Uterine activity stimulators
-Oestrogen - increases from 34-35 weeks
-Prostaglandins
-Inflammation
-Oxytocin
-Alpha adrenergic stimulation - Mechanism of contractions
-Longitudinal fibres draw up the circular fibres to develop the lower segment
-Contractions develop from the uterotubular junction at the fundus and spread downwards
-Myometrial cells communicate via gap junctions
Discuss oxytocin and oxytocin receptors
-Method of initiating uterine activity (2)
-Changes in number over time (2)
-Location of oxytocin receptors (4)
1.Method of initiating uterine activity
-Oxytocin acts on voltage mediated calcium channels
-Oxytocin can act to increase prostaglandin production
2. Changes in number over time
-Low in first trimester
-12 times increased number by term
3. Location of oxytocin receptors
-Greatest in fundus
-Less in lower segment
-Least in cervix
-parietal decidua
Discuss the impact of obesity on uterine contractions (4 points)
- Obesity results in reduced frequency of contractions
- Obesity results in reduced strength of contractions
- Higher levels of cholesterol thought to interfere with signal transduction
- Worsens with increasing weight
Discuss cervical ripening
-Definition (1)
-Biochemical changes to cervix (4)
-Biochemical factors which control cervical ripening (5)
- Definition
-Softening, effacement, dilation of the cervix - Biochemical changes
-Increase in water contents
-Alteration in glycoaminoglycans and proteoglycan content
-Reduction in collagen
-Rearrangement of collagen - widely scattered and dissociated fibres - Biochemical factors controlling cervical ripening
-Prostaglandins
-Oestrogen and progesterone
-Relaxin
-Nitric oxide
-inflammatory mediators
Discuss initiation of labour
1. General points (2)
2. Withdrawal of inhibitory factors (1)
3. Stimulatory factors (2)
4. Fetal factors (2)
- General points
-Multifactorial and poorly understood
-Due to a change in balance from inhibitory to stimulatory factors - Withdrawal of inhibitory factors
Progesterone withdrawal
-Inhibits gap junction in myometrium
-Inhibits oxytocin
-Is anti-inflammatory
-While serum levels don’t fall there may be decreased progesterone sensitivity of the tissues - Stimulatory factors
Corticotrophin releasing hormone
-Released by placental trophoblasts
-Action at CRH receptors retarded by CRH binding protein
-As CRH binding protein drops CRH activity at receptors increases - increases release of prostaglandins and potentiates oxytocin
Increased levels of oestrogen - up regulate myometrial gap junctions and increase oxytocin release - Fetal factors
-Increases in circulating fetal cortisol up regulates prostaglandins
-Increase in fetal cortisol stimulate placental production of CRH
Discuss slow progress in labour
-Prevalence (1)
-Definition in latent phase (1)
-Definition in first stage (5)
-Definition in second stage - nulips (2) and multips (2)
- Prevalence
-Indication for 37% of CS - Definition in latent phase
- >8hrs despite augmentation - Definition in first stage
-Applies to both multips and nulips
-<2cm in 4hrs (<0.5cm / hr) once in active labour
-Slowing of progress of labour for multips
-No change in cervix or dilation after 2 hrs of adequate contractions
-Crossing of the 4hr line on the partogram - Definition in second stage
Nulips:
-No delivery after 2hrs of active phase / 3 if epidural
Multips:
-No delivery after 1hr active phase / 2 if epidural
Discuss using a partogram (5)
-Reduction in prolonged labour
-Reduction in augmentation of labour
-Reduction of sepsis
-Doesn’t impact CS rates
-Recommended by WHO
What factors contribute to slow progress in labour (5)
-Maternal age
-Maternal obesity
-Nulliparity
-Maternal exhaustion
-Maternal infection
Discuss the causes of slow progress in labour (3 categories)
- Power of contractions due to:
-Dehydration
-Infection
-Obesity
-Exhaustion
-Stress - Passenger
-Macrosomia
-Malposition
-Malpresentation
-Fetal anomaly - hydrocephaly / large abdo - Passage
-True CPD - rare and dx of exclusion
-Fibroids
-Congenital abnormality of the genital tract
-Cervical stenosis
-Pelvic anomalies or previous fractures
Discuss management of slow progress in labour
-Prevention (5)
-First stage (7)
-Second stage (4)
- Prevention
-Avoid early hospitalisation to avoid erroneous dx
-Provide 1:1 care in active labour
-Use a partogram
-Encourage mobilisation
-Encourage positioning to avoid malpresentation - No evidence for peanut balls !! - First stage
-Transfer to an obstetric lead unit
-Rehydrate
-Empty bladder
-Offer effective analgesia
-If not fetal or maternal distress and no evidence of obstruction or poor uterine activity can consider expectant management
-Consider amniotomy
-Consider oxytocin - Second stage
-Empty bladder
-Offer amniotomy
-Offer oxytocin to nullips. Care with multips
-Change position to see if helps (Upright or L lateral)
-Do not expedite delivery based on time targets alone. If maternal and fetal wellbeing OK then can consider a further hr(Increased SVB. No impact to pelvic floor/ PPH in one RCT)
Discuss advantages and disadvantages of amniotomy in slowly progressing labour
-Advantages (4)
-Disadvantages (8)
-When should ARM be avoided (5)
- Advantages
-Moderate reduction in risk of CS
-Improves application of head to cervix
-Allows assessment of colour of liquor - Disadvantages
-Doesn’t change the duration of labour for routine ARM
-Increase in painful contractions
-Does not change rates of oxytocin use
-Does not change rates of instrumental delivery
-Doesn’t change use of analgesia
-Increased risk of cord prolapse
-Increased risk of infection
-Increased risk of cord compression and fetal distress - When should ARM be avoided
-HepB, HepC, HIV
-High head
-Head not engaged
When should progress be reassessed in slow progressing labour (2)
Once identified if:
-Expectant management or amniototomy reassess in 2 hrs. If cervical change <1cm needs further action
-If oxytocin repeat VE in 4 hrs. If progress is <2cm consider CS
Discuss oxytocin use in slowly progressing labour
-When to use (2)
-Advantages (3)
-How to use (2)
- When to use
-Offer with care in multips after examination to rule out CPD or obstruction
-Use routinely in nulips - Advantages
-Shortens time to delivery by 2 hrs
-Doesn’t impact mode of delivery
-Doesn’t impact maternal or neonatal morbidity outcomes - How to use
-Titrate up with an increase in dose no closer than 30mins apart. Can do much faster in second stage.
-Repeat VE in 4hrs and if <2cm progress consider CS
Discuss delayed cord clamping
-Definitions (2)
-Volume of blood received by baby (2)
-Recommendations (3)
- Definitions
- <30 seconds = immediate cord clamping
- >2 mins = deferred cord clamping - Volume of blood received by baby - 80-100mL
-75% of placental blood for transfusion is received in the first minute after birth
-Provides baby with approx 3 months of Fe - Recommendations
-Delayed cord clamping for at least a minute
-Don’t delay if baby needs resus
-Can have IM uterotonics while cord unclamped
-Baby on the maternal chest / abdomen doesn’t impact transfusion amount
-Role of cord milking is unclear. May have some benefit in preterm babies
Discuss the benefits of delayed cord clamping
-Benefits for preterm / LBW babies
in short term (11)
-Benefits for preterm / LBW babies in the long term (2)
-Benefits for term babies in the short term (2)
-Benefits for term babies in the long term (2)
- Short term benefits for preterm/LBW babies
-Decreased IVH, NEC, Sepsis
-Decrease need for blood transfusions, surfactant, mechanical ventilation
-Increase in haematocrit, Hb, BP, cerebral oxygenation, RBC flow - Long term benefits for preterm/LBW
-Increases Hb at 10 weeks of age
-May benefit neurological outcomes - Short term benefits for term babies
-Provides adequate blood volume and iron stores
-Increases Hb - Long term benefits for term babies
-Improves Hb and haematocrit at 2-4months
-Improves Fe status up to 6 months
Discuss cord blood banking
-What is it (1)
-What can it be used for (2)
-What types of cord blood donation is there (2)
-What are the benefits
-What are the downsides
-What is the RANZCOG recommendation
- What is cord blood banking
-Collecting of umbilical cord blood for haematopoetic stem cells to be used later for clinical purposed - Can be used by other compatible receivers to treat
-Haemoglobinopathies
-Haemotological cancers - Types of donation
-Altruistic to unrelated people who don’t have a suitable bone marrow donor
-Direct to a sibling who has a disease amenable to haematopoeitic stem cells - Benefits
-Tolerates greater HLA mismatch from recipient
-Less graft vs host disease
-Extends the donor pool
-Lower risk of viral infection - Down sides
-Expensive
-No publically funded bank in NZ
-Logistically complex
-Pubic banks in Australia are under represented by some ethnic groups
-May not be enough sample to treat large children or adults. - RANZCOG guideline
-Supports collection of altruistic and direct cord blood donations for at risk families
Discuss home births
-Incidence of home births in Australia and NZ
-Benefits for home births
-Risks of home birth
- Incidence of planned home births
-NZ 4%
-Australia 1%
-25% of planned births of nulliparous women outside hospital need transfer - Benefits of home birth
-Increased Vaginal birth rate RR 3
-Less interventions - CS, instrumental births, episiotomy
-No increase risk in neonatal death
-No worse outcome for women who have required transfer
-Less perineal trauma RR 0.04
-Less NICU admission - Risks of home birth
-No difference in perinatal death rate - SB or early neonatal (Hospitals should be higher as much higher risk pregnancies)
-Transfer rates 1:3 nulliprous 1:17 multiparous
What are the RANZCOG recommendations for home birth (9)
- College supports hospitals as the safest place of birth
- Women should have informed choice in maternity care including choice of birthing location
- Women contemplating planned home birth must be provided with accurate information free of bias
- Even in pregnancy without complicating factors the risk of home birth is at a level which is unacceptable to most women.
- When a pregnancy has any risk factors then home birth can be particularly dangerous
- Where women remain intent on a planned birth health practitioners should be confined to Ob/LMC
- Women should meet the criteria for homebirth as specified in the local / national guideline
- A midwife practising homebirth must have established professional relationships with an obstetrician for referral and consultation.
- All practitioners undertaking homebirth should have established referral pathways into a local hospital and transfer in a timely manner with for warning
Discuss water immersion for labour and delivery
-Benefits (1)
-No impact (4)
- Benefits
-Reduces regional analgesia use (RR 0.91) - No impact
-No difference between SVD, Instrumental delivery or CS
-No difference in maternal, fetal or neonatal risks
Discuss water birth
-Situations where possible
-Situations where not possible
- Situations where possible
-If have telemetry and CFM is required
-Can have third stage in water but be aware blood loss hard to estimate
-Can use oxy in water if have CFM telemetry
-PROM as long as on Abx - Situations where not possible
-Where staff are not trained to manage a woman labouring and birthing in water
-During an obstetric emergency
Discuss diet in labour
As per RANZCOG a light diet and drinking for hydration is fine in established labour unless concern for anesthetic possibility
Discuss active vs physiological management of third stage in low risk women (RANZCOG guidelines)
-What does active management entail (3)
-What is the evidence for active management (5)
-What are RANZCOG recommendations (3)
- Active management
-Clamping and cutting of the cord
-CCT
-IM or IV uterotonic - What is the evidence for active management
-Uncertain if reduces risk of PPH >1000mL
-Probably reduces theraputic uterotonic use
-Probably increases maternal Hb
-Probably reduces risk of PPH 500mL
-May reduce maternal blood transfusions - RANZCOG recommendations
-Discuss management of third stage and options in the AN period
-Acknowledge that with low risk women the benefit of active management is less certain
-Women should have info to make an informed choice.
