Labour Flashcards
What shape is the posterior fontanelle?
Triangle
What shape is the anterior fontanelle?
Diamond
What is the ideal cephalic presentation of the fetal head during labour?
Occipito-anterior
What proportion of pregnancies have to be induced?
1 in 5
What is an induction of labour?
Labour is initiated by the use of medications to ripen cervix usually followed by Artificial rupture of amniotic membranes
What is an amniotomy?
The intentional rupture of the amniotic sac
What are the indications for the induction of labour?
- hypertensive disorders
- Maternal diabetes
- Prolonged pregnancy
- Twin pregnancy
- Prelabour rupture of membranes
- Foetal growth restriction or macro Sonia
- Maternal request in exceptional circumstances
- Previous still birth or interosseous death
- Post-dated uncomplicated pregnancy
What are the contraindications for induction of pregnancy?
- malpresentation
- Placenta praevia/vasa praevia
- Prolapsed umbilical cord
- Foetal distress
- Anatomical abnormalities e.g pelvic tumour
What is the Bishop’s score used for?
Used to clinically assess the cervix. The higher the score, the more progressive change there is in the cervix and indication that induction is likely to be successful.
What aspects of the cervix are assessed in the Bishop Score?
Position Consistency Effacement Dilation Station
What medications are used in the induction of labour?
• topical prostaglandin analogues e.g misoprostol
- encourage cervical dilutions and effacement
- alternative is balloon catheter- favourable over prostaglandins
• IV synthetic oxytocin e.gsyntocinon
- initiates uterine contractions
• require CTG monitoring
What are the complications for the induction of labour?
- uterine hypertonicity
- Foetal distress
- Adverse effect of drugs (hypotension, hyponatraemia)
- Failed induction
- Caesarean section
- Ruptured uterus
What is the process for the induction of labour?
Once cervix has dilated and effaced, an amniotomy can be performed. A bishop score of 7 or more is considered favourable for amniotomy.
Once amniotomy is performed, IV oxytocin can be used to achieve adequate contractions (unless contractions spontaneously start)
Aim for 4-5 contractions in 10 mins
What is meant by effacement of the cervix?
The cervix stretches and gets thinner
Name common Intrapartum complications. (Powers, passage and passenger)
- inadequate uterine activity
- cephalopelvic disproportion (CPD)
- Other reasons for obstruction
- malposition
- malpresentation
Fetal distress
How is progress in labour evaluated?
By a combination of abdominal and vaginal examinations to determine:
- cervical effacement
- cervical dilatation
- descent of the fetal head through the maternal pelvis
What is suboptimal progress in labour defined as?
Less than 0.5cm per hour for primigravid women
Less than 1cm per hour for porous women
How is inadequate uterine activity managed?
IV synthetic oxytocin increases strength and dilatation of the contractions.
Exclude an obstructed labour
What is cephalopelvic disproportion?
The fetal head is in the correct position for labour but it is too large to negotiate maternal pelvis to be delivered.
Genuine CPD is very rare.
What is the cause of relative CPD?
If there is malposition and the fetal head is in a suboptimal position for labour.
What are common causes of obstruction in labour?
Placenta praevia
Fetal anomaly
Fibroids
What is malposition?
Involves the fetal head being in a suboptimal position for labour: occipito-posterior and occipito- transverse
What are the main causes of fetal distress?
Hypoxia, infection, cord prolapse, placental abruption and vasa praevia.
How is a fetus monitored in labour?
Intermittent auscultation of the heart
Cardiotocography
Fetal blood sampling
Fetal ECG