Labour and its complications Flashcards
Define primary postpartum haemorrhage
blood loss of >500ml from the genital tract occurring within 24 hour of delivery
Define secondary postpartum haemorrhage
‘excessive’ blood loss occurring between 24 hours to 6 weeks after delivery
What are the causes of primary post partum haemorrhage?
4 T’s
TONE
previous PPH, high BMI, increased maternal age, prolonged labour, PROM, polyhydramnios, multiple pregnancy, pre-eclampsia, emergency C -section
TRAUMA - episiotomy, tears, uterine rupture, C section incision
THROMBIN- DIC (due to eclampsia, placenta abruption), coagulation disorder (von willebrand disease)
TISSUE- placenta praaevia, placental accreta
What is uterine atony?
failure for uterus to contract properly after delivery caused by over distended uterus, prolonged labour, infection or retained placenta (cause of TONE)
What are the causes of secondary PPH?
retained products of conception
infection e.g. endometritis
What are the intrapartum risk factors for PPH?
induction of labour use of oxytocin vaginal operative delivery C- section prolonged 1st/2nd or 3rd stage
How is PPH investigated?
vaginal examination
How is PPH managed and treated?
- IV access obtained
- blood cross matched and blood volume restored
- treat causes of bleeding
uterine causes = oxytocin IV +/- ergometrine IV + iM carboprost OR surgery - high flow oxygen
- in signs of shock -> ABCDE -> blood transfusion
Define preterm delivery
if delivery occurs between 24-37 weeks gestation
What are the possible neonatal complications with a preterm delivery?
neonatal intensive care perinatal mortality cerebral palsy chronic lung disease blindness minor/long term disability
What are the risk factors for preterm delivery?
previous preterm baby lower socio-economic class extremes of maternal age pregnancy complications - pre-eclampsia, IUGR maternal medical conditions e.g. renal failure, diabetes, thyroid disease STI multiple pregnancy congenital fetal abnormalities
What can be done to prevent preterm labour?
Progesterone supplements e.g. progesterone pessaries - reduce risk of preterm labour in women at high risk
Cervical cerclage - >1 sutures in cervix to strengthen and keep closed
Infection e.g. screen and treat UTI and STI
fetal reduction
treat polyhydramnios - needle aspiration + NSAIDs
How is preterm labour investigated?
CTG
ultrasound
transvaginal scanning
How is preterm labour managed?
- steroids - given between 24-34 weeks, stimulate production of surfactant
- detect and prevent infection
- magnesium sulphate - neuroprotective
- delivery - prefer vaginal delivery or elective C-section for breech presentations
What is a retained placenta?
if the placenta has not been expelled following 60 minutes of the third stage of labour, it is unlikely to be expelled spontaneously
How do you help the placenta separate if it is retained?
rub up a contraction
give 20u oxytocin into umbilical vein
if still not worked, consider manual removal
How does amniotic fluid embolism present?
sudden dyspnoea **
hypotension **
end of first phase of labour/ shortly after delivery
+ seizures, pulmonary oedema, breathlessness, distress, high mortality!
How is amniotic fluid embolism managed?
obtain IV access
give fluids rapidly
transfer to ICU
prevent death from resp failure e.g. oxygen, ventilator support
What happens with a cord prolapse?
umbilical cord descends below the presenting part -> becomes compressed -> spasm -> hypoxia in the baby
What is cord prolapse associated with?
breech and transverse lie
preterm labour
How is cord prolapse managed?
mother in knee-chest position
manually apply pressure to foetus
emergency C-section!!!
what are the risk factors for shoulder dystocia?
macrosomia abnormal pelvis maternal diabetes induced labour prolonged labour increased maternal BMI
how is shoulder dystocia managed?
1st line= McRoberts manoeuvre - legs hyper extended on abdomen and suprapubic pressure
2nd line = rubin manoeuvre
consider episiotomy
C-SECTION!
what Is a complication of shoulder dystocia?
Erbs palsy - damage to upper brachial plexus from shoulder dystocia
causes adduction and internal rotation of arm “waiters tip”
why are episiotomies performed?
performed to enlarge the outlet and prevent 3rd degree tears
What is an uterine rupture?
uterus can tear or old C-section scar open -> foetus extruded -> uterus contracts down -> bleeds from rupture site -> fetal hypoxia -> huge internal haemorrhage
How does uterine rupture present?
fetal heart rate abnormalities
cessation of contractions
constant vaginal bleeding
How is an uterine rupture managed?
IV fluids
blood transfusion
removal of uterus if severe
Define “slow labour”
progress slower than 1cm/hour after latent phase
Define “prolonged labour”
> 12 hour duration after latent phase
What are the causes for failure to progress in labour?
THE POWERS - inefficient uterine action
THE PASSENGER - fetal size, disorder of rotation (occipital- transverse or posterior), disorder of flexion (brow, face)
THE PASSAGE - cervical resistance, cephalon-pelvic disproportion, pelvic deformities
Outline the 3 factors recognised as key participants in labour
- the power = the degree of force expelling the foetus
- the passage = the dimensions of the pelvis and resistance of soft tissues
- the passenger = the diameters of the fetal head
Describe “the power” and how it contributes to labour?
once labour established, uterus contracts for 45-60 seconds every 2-3 minutes
this pulls the cervix up (effacement) and causes dilation
this is helped by the pressure of the head as the uterus pushes the head into the pelvis
Describe “the passage” and how it contributes to labour?
BONY PELVIS
inlet transverse diameter= 13cm / outlet transverse diameter= 11cm
use ischial spines to assess level of descent of the head on vaginal examination
SOFT TISSUES
cervical dilatation is dependent on contractions, pressure of fetal head on cervix and ability for cervix to soften and allow distention
How is the level of descent of the head in labour assessed?
in lateral wall of round mid pelvic, ischial spines are palpable and used as landmarks to assess level of descent of head on vaginal examination
station 0 = head it at levels of spine
spine +2 = 2cm below the spines
spine -2 = 2cm above the spines
Describe “the passenger” and how it contributes to labour?
- attitude: extension and flexion
vertex presentation is the ideal attitude where there is MAXIMAL FLEXION keeping the head bowed and presenting diameter 9.5cm from anterior fontanelle to below the occiput at back of head - position: rotation
usually delivered with the occiput anterior, head rotates 90 degrees during labour - size of the head
the head can be compressed in pelvis as the sutures allow the bones to come together and overlap slightly = moulding
Define cervical ripening
softening of the cervix that begins prior to the onset of labour contractions and is needed for cervical dilation and passage of the foetus
What is used to record progress in labour?
cartogram - used to record progress in dilatation of the cervix +/- descent of the head
assessed on vaginal examination and plotted against time
How should the mother be assessed during labour?
- maternal obs - pulse *, BP, temp
- fetal heart rate - every 15 mins or continuously on CTG
- liquor colour
- contractions : freq, strength and regularity every 30 mins
- vaginal examination: every 4 hours to check progression of head descent
- maternal urine: checked for ketones and protein every 4 hours
Define “normal birth”
birth without induction of labour, spinal or epidural analgesia, general anaesthesia, forceps or ventouse delivery, C-section or episiotomy
Define “presentation”
the part of the foetus that occupies the lower segment of pelvis
Define “position”
position of the head describes its rotation e.g. OT, OP, OA
Define “attitude”
describes the degree of flexion e.g. vertex, brow, face
Outline the sequence for the passage through the pelvis for a normal vertex delivery
- ENGAGEMENT AND DESCENT: the head enters pelvis in occipito-transverse position
- DESCENT AND FLEXION: head descends into mid cavity and flexes as cervix dilates
- INTERNAL ROTATION TO OCCIPITO-ANTERIOR: occurs at ischial spines, head rates 90 degrees so face is facing sacrum
- CROWNING- head extends, distending the perineum until it is delivered
- RESTITUTION - the head rotates so occiput is in line with the fetal spine
- EXTERNAL ROTATION - shoulders rotate until biacromial diameter is anteroposterior
- DELIVERY OF THE ANTERIOR SHOULDER
- DELIVERY OF THE POSTERIOR SHOULDER
Outline the process of initiation and diagnosis of labour
prostaglandin production revives cervical resistance and increases release of oxytocin from posterior pituitary gland which stimulates contractions
labour diagnosed when painful regular contractions lead to effacement and then dilatation of the cervix
What is effacement and what happens when this occurs?
= when the normally tubular cervix is drawn up into the lower segment until it is flat
“show” occurs / pink white mucuous plug from the cervix
+/- rupture of the membranes causing release of liquor
What is involved in the first stage of labour?
LATENT PHASE
cervix dilates slowly for the first 3cm (takes 6 hours for first 3 cm)
irregular contractions - every 5-30 mins, lasts 30 secs
“show” mucoid plug
cervix effacing and thinning
head enters in occipital lateral position
ACTIVE PHASE
regular frequent strong contractions - every 3-5 mins and last 1 min
oxytocin involved
cervical dilatation of 1cm/hour in nulliparous women/ 2cm/hr in multiparous (3-10cm)
cervix then fully effaced and dilated
What is involved in the second stage of labour?
PASSIVE STAGE
from full dilatation until head reaches the pelvic floor and women feels desire to push
= absence of pushing
ACTIVE STAGE
mother is pushing alongside contractions
pressure of head on pelvic floor produces desire to bear down
foetus delivered after 20-40 mins
deliver head in occipital anterior position
if longer than 1 hour, think about ventouse, forceps or C section
THIS STAGE DEPENDS ON THE 3 P’s
What is involved in the delivery stage of labour?
- head reaches perineum, it extends to come up out of the pelvis
- perineum begins to stretch and can tear
- head restitutes, rotates 90 degrees and adopts transverse position
- with the next contraction, shoulder comes under they symphysis pubic first
- the posterior shoulder is helped by lateral body flexion in an anterior direction
- rest of body follows