abnormal labour Flashcards
what is induction of labour
attempt made to instigate labour artificially using medication and/or devices to ‘ripen cervix’ followed usually by artificial rupture of membranes (amniotomy performed)
Bishop’s score
used to clinically assess cervix
higher score more progressive change there is in cervix and indicates that inductiion is likely to be successful
everyone gets a bishops score to see if and what interventions needed
when can amniotomy be performed
once cervix has dilated and effaced (shortened)
bishops score of 7 or more
what is amniotomy
artificial rupture of foetal membranes (‘waters’) using a sharp device e.g amniohook
what happens once an amniotomy has been performed
IV oxytocin can be used to achieve adequate contractions (unless they start spontaneously)
aim for 4-5 contracs a min
indications for induction
- diabetes
- post dates - term + 7days
- maternal need for planning of delivery e.g. receiving DVT Rx
- foetal reasons: growth concerns, oligohydramnios
- social/maternal request
- twin pregnancy
- prev stillbirth or IUD
- hypertension
contraindications for induction
- malpresentation
- placenta praevia/vasa praevia
- prolapsed umbilical cord
- foetal distress
- anatomical abnormalities e.g. pelvic tumour
medication used during induction of pregnancy
topical prostaglandin analogues e.g. misoprostol
- cervical dilatation and effacement
- alternative = balloon catheter
IV synthetic oxytocin e.g. syntocinon
complications of induction of labour
uterine hypertonicity foetal distress adverse effects of drugs (hypotension, hyponatremia) failed induction C section ruptured uterus
intrapartum complications: categories
powers
passages
passenger
inadequate progress in labour may be due to
powers
-inadequate uterine activity
passages
- cephalopelvic disproportion
- other reasons for obstruction e.g. fibroid
passenger
- malposition
- malpresentation
how is progress in labour evaluated
cervical effacement
cervical dilatation
descent of foetal head through maternal pelvis
how is suboptimal progress in labour defined in active 1st stage
cervical dilatation
< 0.5cm per hour for primigravid women
<1cm per hour for parous women
obstructed labour
woman continuing to labour and contract but cervix not dilating
can result in serious complications e.g. uterine rupture
what will happen if contractions are not adequate
foetal head will not descend and exert force on cervix and so cervix will not dilate
how can we increase strength and duration of contractions
giving synthetic IV oxytocin to mother
cephalopelvic disproportion
mismatch between mother’s pelvic dimensions and baby
baby’s head in correct position but is to large to negotiate maternal pelvis and be born
what happens to fetus as result of cephalopelvic disproportion
caput - swelling on baby head
-moulding - sutures on baby head cross over eachother
placenta praevia
low line placenta
placenta presenting and will come out first, cutting out supply to baby
usually accompanied by catastrophic haemorrhage
malpresentation
presenting part is not the vertex - baby head isnt down
breech nothing presenting (transverse lie)
malposition
foetal head in a suboptimal presentation for labour
e..g. occipito-posterior, occipito-transeverse
ideal baby position
occipito-anterior
baby facing sactrum
main causes of feotal distress
hypoxia infection cord prolapse placental abruption vasa praevia
when is foetal distress suspected
when foetal heart rate decelerates after contraction
how is fetal wellbeing in labour determined
intermittent auscultation of foetal heart (low risk labours)
cardiotocography
foetal blood sampling
foetal ECG
how is fetal blood sampling performed
speculum used to take fetal scalp blood sample
when is fetal blood sampling indicated
CTG is abnormal and cervix dilated 8cm
what does fetal blood monitoring provide
direct measurements from baby
pH and base excess
lactic acid
low pH = foetal hypoxia
what does CTG represent
autonomic and central nervous system activity, and changes due to hypoxia
indications of CTG
- induction
- post-/pre-maturity
- multiple pregnancy
- underlying maternal health conditions e.g. cardiac, diabetes
- ante-/intra-partum haemorrhage
- pyrexia
- epidural anaesthesia
- abnormalities noted on intermittent auscultation
post maturity
> 42wks
prematurity
<37wks
operative deliveries
instrumental deliveries - forceps/ventouse
planned/emergency caesarean section
caesarean section
deliver fetus through incision on abdominal wall and uterus
2 main types C section
lower uterine segment incision - most common, horizontal incision
classical - very rarely used now, longitudinal incision in upper segment uterus
C section indications
foetal distress failure to progress in labour failed induction of labour malpresentation severe pre-eclampsia placenta praevia twin pregnancy with a non-cephalic presenting twin repeat CS
categories of C section: I emergency
within 30 mins
immediate threat to life of woman or foetus
categories of C section: II urgent
within ~90mins
maternal or foetal compromise but not immediately life threatening
categories of C section: III scheduled
no time limit
requiring early delivery but no compromise
categories of C section: IV elective
no time limit
at time to suit woman and maternity team
~1/2 c sections
complications of C sections
injury to structure e.g. bladder
haemorrhage
DVT
infection
3rd stage complications of pregnancy
from birth of baby to birth placenta
retained placenta
post-partum haemorrhage
tears
retained placenta
placenta doesn’t deliver
oxytocic drug and controlled cord traction
if not delivered 60mins may need go theatre for manual removal
1st degree tear
vaginal mucosa only
2nd degree tear
perineal skin only
3rd degree tear
involving anal sphincter complex
4th degree tear
involving rectal mucosa
