W03: Normal Labour; Abn Labour Flashcards
Describe the physiological process of labour and birth
- cervix softens, myometrial changes allowing coord contractions
- ⇧oxytocin + prostaglandins; ⇩progesterone = INITIATE LABOUR
- ⇧cervical dilatation
STAGE 1:
latent phase = irregular contractions, dilat. up to 4cm
active first stage = 8-12hrs, regular painful contractions, dilat 4-10cm
transition = physical changes: shaking, vomit, poo
STAGE 2
full dilatation to birth
passive followed by active
STAGE 3
birth until expulsion of placenta and membranes; physio. mgmt.,
active mgmt.
Describe methods of assessing progress in labour
Abdo examination can elucidate the position and possible presentation
- cephalic
- right or left transverse
- oblique (left/right)
+ obs
+ vaginal examination
+ liquor monitoring
+ palpation. of contractions
+ rhomboid of michaelis & anal cleft line
What is normal labour
expulsion of the fetus, placenta, and membranes via the birth canal
- spont.
- 37-42w gestation
- fetus presenting by the vertex
= spontaneous vaginal birth
Mechanism of labour
- engagement of head and descent
- flexion: cervical flexion upon pelvic floor = smaller diameter allowing passage
- int. rotation
- crowning @ vulva and extension of the head
- ext rotation & restitution: realignment of shoulders w/ head
- internal rotation of the head and external rotation of the head
- lateral flexion of shoulders
What is engagement
largest diameter of fetal head fits into the largest diameter of the maternal pelvis
What is descent
baby descends through the pelvic inlet towards the pelvic floor
dt
- uterine contractions
- amnio fluid pressure
- abdo muscle contractions
What is internal rotation
head rotates from Left/Right occipito-transverse to an OCCIPTO-ANTERIOR POSITION followed by CROWNING
Assessing fetal wellbeing
auscultation or continuous monitoring to assess fetal heart rate
* 110-160bpm
describe the stress of labour on the fetus
- hypoxic stress
- infection
- cord prolapse
- placental abruption
- vasa praevia
- uterine hyper. stim
Describe complications in labour and understand the basis of their management
indications for induction:
-DM
- after due date
- maternal need for planning of delivery: DVT tx
- fetal reasons
- social/maternal requests
- intrapartum complications: powers, passages, passenger
- weak uterine contractions
- malposition (common)
> IV oxytocin = increase contractions (power)
Labour Induction
> cervical ripening via PROSTAGLANDINS or BALLOON
- BISHOP’S SCORE: clinically assess success of induction
- AMNIOTOMY. = artifical rupture of fetal membranes
- followed by IV oxytocin = contractions
Whats effacement
Effacement is the thinning and shortening of the cervix. It happens at the end of pregnancy in preparation for childbirth.
Monitoring fetus
- auscultation
- CTG: cardiotocography
- fetal blood sampling: speculum scalp blood sample
- fetal ecg = abn = blood sample
3rd stage complications
- retained placenta
- post partum haemorrhage
4Ts - tone
- trauma
- tissue
- thrombin
- tears: graze; 1st to 4th degree
Signs of PPH (post part. haemorr.)
- hypotensive, tachycardic
- decreased red cell
- pale, clammy, vommy
- abdo pain
Outline the global burden of maternal and perinatal mortality
prolonged labour = complications
- uterine rupture
- obstetric fistula
- pphaemor.
untreated hypertensive disorders
infection: leading cause in sub-sahran africa
- post-birth infect. top mortality cause
intrauterine death, preterm birth, neonatal death
Outline a basic understanding of the definitions, data sources and measurement challenges
a
Outline the major options for reducing the magnitude of maternal mortality at a population level
- oxytocin injections
- hygiene
- early tx of infection
- BP control and Mg sulphate in severe pre-ecampsia
- education
- better infrastructure and access
- poverty; cultural practice; poor health services
Obstetric fistula
prolonged labour ompresses soft tissues around uterus/baby head = necrosis = fistula forming between spaces such as bladder or rectum
> sx repair
Morbidly adherent placenta
normal placenta = placenta separated from uterine wall by fibrinous layer
placenta accreta = firm attach. to uterine
placenta increta = invasion at elast halfway
placenta percreta = invasion THROUGH to nearby tissues/ structures
To describe the normal changes to the mother in the puerperium
*6w post-birth; midwife first 9-10d then health visitor
- screen for abn bleeding, infection
- debrief emergency events
- mental health
+ 6w postnatal check at GP
To describe the potentially serious medical problems arising in the postpartum period
- complications in breast feeding
- blocked ducts, mastitis
- p.partum haemorr.
- venous thromboem.
- significantly postpartum hypercoagulable state
> prophylaxis
LMWH (warfarin safe for breast feeding)
- sepsis
> IV abx
- psychiatric disorders
- postnatal depression
> tx
- pre-eclampsia: postnatal eclamptic seizures
> antihypertensives
+ follow up
1º and 2º PPHaemorr.
1º = 500ml loss within 24hrs
- tone
- trauma
- tissue
- thrombin
2º = 500ml+ loss from 24hrs to 6w
- retained tissue
- endometritis
- tears/trauma
Red flags for thromboembolic disease post partum
unilateral leg swelling/pain
SOB or chest pain
unexplained tachy.
= high index of suspicion for VTE
CTGs: how, and indications
Abn or intrapartum complications = indicate CTG
- autonomic and CNS activity changes dt hypoxia
- USS detects fetal HR
- contractions of uterine wall detected
- continual CTG dt
- induction of labour, post maturity/ pre-maturity
CTG Interpretation
DR C BRAVADO
DR = determine risk
C = contractions/10mins
* lower bar; no. of peaks per 20squares = peaks/10mins
BRA = Baseline Rate when accelerations and decelerations excluded
V = variability: zig zaggging
A = accelerations: upward peaks
D = decelerations: troughs
* prolonged/late = fetal hypoxia
O = overall: good/bad/ etc.
Fetal blood sampling: decisions
blood sampling confirms signs of CTG hypoxia
pH > 7.25 = rpt in 1hr if CTG remains abn
pH 7.21-7.24 = rpt in 30mins if CTG remains abn.
pH < 7.2 = IMMEDIATE DELIVERY
C-Section types
-Lower uterine segment incision; commonest
- Classical: rarely used - longitudinal
Indications of C-sect
- foetal distress
- failure to progress in labour/ induction
- malpresentation
- severe pre-eclampsia
- placenta praevia
Categories of C-sect
I: emergency = within 30mins
II: urgent = 90mins: maternal/foetal compromise
III: scheduled: early delivery but no compromise
IV: elective: time to suit woman and team
Complications of C-Sect
- injury: bladder, ureters
- haemorr
- DVT
> abx
lmwh
+ catheterisation
+ regional anaesthesia
LT risk:
* placenta praevia or accreta
* antepartum stillbirth
* uterine rupture
* post-op lesions
