Labour and Birth Flashcards
What is the lie of the fetus? What are the types?
Relationship of fetal long axis to uterus long axis
Longitudinal
Oblique
Transverse
What is the presentation of the fetus? What are the types?
Fetal part that enters the maternal pelvis
Cephalic is the safest
Face, Brow, Breech, Shoulder
What is the vertex/position of the fetus?
Position of the fetal head as it exits the birth canal
Occipito-anterior is safest
How are malpresentation of the fetus managed?
Brow - C Section
Shoulder - C-section
Face - if chin anterior then normal labour possible, chin posterior then C Section
What happens in most malpositions?
90% spontaneously rotate to occipito-anterior as labour progress
What is the management if a malposition doesn’t rotate?
Rotation and operative vaginal delivery attempted
C Section can be performed
How common is breech presentation?
20% at 28 weeks
3-4% at term - majority spontaneously turn
What are the risk factors associated with breech presentation?
85% spontaneous
Uterine abnormality
Lax uterus - multiparty
Placenta praevia
Abnormal amniotic fluid
How is breech presentation identified?
Palpation of abdomen
Fetal heart auscultated higher in abdomen
USS
20% not diagnosed until labour - fetal distress or foot felt
What should happen if a breech is identified at 35/36 week scan?
Refer for scan and specialist opinion
What are the types of breech delivery?
Complete breech
Frank breech
Footling breech
How are breech babies delivered?
Try ECV first
C Section or Vaginal depending on woman and specific presentation
Footling breach - vaginal contraindicated
How is a breech baby delivered vaginally?
Hand off baby - traction can lead to neck hyperextension and head getting trapped
Flex fetal knees - deliver legs
Lovsetts - rotate body to deliver shoulders
MSV - flex head
What complications are associated with breech delivery?
Cord prolapse
Fetal head entrapment
Premature rupture of membranes
Birth asphyxia
When is external cephalic version carried out?
36 weeks if nulliparous - 40% success
37 weeks if multiparous - 60% success
What is the result of external cephalic version?
Reduce risk of non-cephalic birth or need for caesarian
Still higher risk of complications than spontaneous cephalic
Safe with no risk of intra-uterine death
<5% revert to breech
What are the CI’s for external cephalic version?
APH within last week Ruptured membranes Major uterine abnormalities Abnormal CTG Multiple pregnancy
What are the complications associated with external cephalic version?
Placental abruption
Uterine rupture
Fetal-maternal haemorrhage
Fetal distress
What are the types of premature rupture of membranes?
Premature rupture of membranes - >1hr before onset of labour at >=37 weeks gestation
Pre-term premature rupture of membranes - rupture occur before 37 weeks gestation
How common is premature rupture of membranes?
10-15% of term pregnancies
Minimal risk to mother and fetus
How common is preterm premature rupture of membranes?
~2%
Higher rates of maternal and fetal complications
What are the risk factors associated with premature rupture of membranes?
Multiple pregnancy Lower GU infection Smoking Vaginal bleeding during pregnancy Polyhydramnios Cervical insufficiency Invasive procedures - amniocentesis
What are the differentials for premature rupture of membranes?
Urinary incontinence
Loss of mucus plug
Normal vaginal secretions
Secretions associated with infection
What is the pathophysiology of premature rupture of membranes?
Normal weakening occurs earlier than normal due to:
- Higher levels of apoptotic markers in amniotic fluid
- Infection - cytokines weaken membrane
- Genetic disposition
How is a premature rupture of membranes diagnosed?
Maternal history of rupture and positive examination findings
Sterile speculum examination - amniotic fluid draining from cervix and pooling in vagina when lying down for 30 mins
Reduced amniotic fluids suggestive
What is important to investigate if you suspect premature rupture of membranes and what should you avoid?
High vaginal swab done - look for group B strep
Avoid digital vaginal exam until in labour –> poss. intrauterine infection
What should be given if a woman has isolated group B strep?
Clindamycin or Penicillin
What does premature rupture of membranes cause?
Amniotic fluid stimulate uterus and labour occur within 24-48 hours
If labour doesn’t occur following premature rupture of membranes, what should be done?
<34 weeks - aim for increased gestation
34 weeks + - induce labour
How should premature rupture of membranes before 36 weeks be managed?
Monitor for chorioamnionitis
Advise against sexual intercourse
Prophylactic erythromycin
Corticosteroids (dexamethasone) - fetal lung development
How should premature rupture of membranes >36 weeks be managed?
Monitor for chorioamnionitis
What are the complications of premature rupture of membranes?
Prematurity
Sepsis
Pulmonary hypoplasia
How can premature rupture of membranes be prevented?
Intravaginal progesterone and cervical cerclage - if history of Preterm-PROM
What is chorioamnionitis?
Result of ascending bacterial infection of amniotic fluid, membranes or placenta
What are the risk factors for chorioamnionitis?
Preterm premature rupture of membranes
How is chorioamnionitis managed?
Prompt delivery of foetus
IV antibiotics
How commonly is labour induced?
20% of pregnancies
What are the indications for induction of labour?
Prolonged pregnancy Premature rupture of membranes Fetal growth restriction Intrauterine fetal death Maternal health problems - diabetes, hypertension, obstetric cholestasis
What are the methods of induction?
Vaginal prostaglandins
Membrane sweep
Amniotomy +- oxytocin
How do vaginal prostaglandins induce labour?
Ripen cervix and role in contractions
Taken as tablet, gel or pessary
Induction can take days
How does a membrane sweep induce labour?
Adjunct to induction
Gloved finger rotate against fetal membrane - aim to separate from decidua and release prostaglandins
Explain the use of an amniotomy to induce labour
Used if vaginal prostaglandins CI
Membranes ruptures using hook - release prostaglandins to stimulate labour
Oxytocin given to increase strength and freq. of contractions
Only performed once cervix is ripe
What are the absolute contraindications for induction of labour?
Cephalopelvic disproportion Major placenta praevia Transverse lie Vasa praevia Cord prolapse Active primary genital herpes
What are the relative contraindications for induction of labour?
Breech
Triplet or higher order pregnancy
2 or more previous low transverse C sections
What is the bishop’s score?
Scoring system used to assess cervical ripeness
Score >9 - labour likely commence spontaneously
Score <5 - labour unlikely to start without induction
Describe the factors in bishop’s score
Cervix: 0 points, 1 point, 2 point, 3 point
Position - posterior, midline, anterior, NA Consistency - firm, medium, soft, NA Effacement - 0-30%, 40-50%, 60-70%, >80% Dilation - closed, 1-2cm, 3-4cm, >5cm Station - -3, -2, -1 and 0, +1 and +2
What complications are associated with induction of labour?
Uterine hyperstimulation
Failure of induction - req. C Section
Uterine rupture
Cord prolapse - occur in amniotomy with rush of fluid
Intrauterine infection - prolonged membrane rupture and repeated vaginal examinations
What is uterine hyperstimulation associated with and how is it managed?
Fetal distress
Terbutaline - anti-contraction agent
What instruments can be used to aid delivery?
Forceps Vacuum extraction (Ventouse)
How can instrumental deliveries be categorised?
Classified by degree of fetal descent - lower they are, lower risk of complications
Outlet
Low
Midcavity
What does it mean if a instrumental delivery is classified as outlet?
Fetal scalp visible with labia parted
Fetal skull reached pelvic floor
Fetal head on perineum
What does it mean if a instrumental delivery is classified as Low?
Leading point at +2 station or lower
Subdivided depending on rotation - more or less than 45 degrees
What does it mean if a instrumental delivery is classified as midcavity?
Head 1/5 palpable abdominally
Leading point between 0 and +2
Subdivided depending on rotation - more or less than 45 degrees
What are the indications for instrumental delivery?
Maternal - Inadequate progress of 2nd stage of labour - Exhaustion - Hypertensive crisis - CVS disease - Myasthenia gravis and spinal cord injury Fetal - Compromise - Protect head during breech
What is considered inadequate progress of 2nd stage of labour?
Nulliparous - 2 hours of active pushing
Multiparous - 1 hour of active pushing
When should instrumental delivery be abandoned for C Section?
No descent seen in 3 pulls
What are the contraindications for instrumental delivery?
Bleeding or fracture predisposition of fetus
Face delivery
<34 weeks if ventouse
What are the requirements for instrumental delivery?
Fully dilated cervix Occipito-anterior position Ruptured membranes Cephalic presentation Engaged presenting part Pain relief adequate Sphinter (bladder) empty
What maternal complications are associated with instrumental delivery?
Maternal mental health - can develop tocophobia
Urinary and faecal incontinence
3rd/4th degree tears
Pelvic organ prolapse
What fetal complications are associated with instrumental delivery?
Cephalhaematoma
Facial bruising
Retinal haemorrhage
What is the difference between caput seccedaneum and cephalhaematoma?
Caput secumdum
- Soft puffy swelling due to oedema
- Present at birth, cross the midline and resolve within days
Cephalhaematoma
- Bleeding between periosteum and skull
- Present within hours, doesn’t cross midline and resolve within months
What are the complications of a prolonged second stage of labour?
Chorioamnionitis
3rd and 4th degree tears
Uterine atony