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
What are the conditions where the placenta is retained?
Placenta adherens
Trapped placenta
Partial accreta
What happens in placenta adherens?
Myometrium fair to contract behind placenta
What happens in trapped placenta?
Detached placenta trapped behind closed cervix
What happens in partial accreta?
Part of placenta adhered to myometrium
What are the complications associated with retained placenta?
PPH
Infection
What are the signs the placenta has separated?
Sudden rush of blood
Fundus move higher and become more rounded
Increase length of visible umbilical cord
Raising fundus doesn’t cause cord to decrease in length
What should be done if a placenta has separated?
Deliver placenta by rubbing up uterus
Push towards vagina with expulsion of placenta and membranes
What should be done if the placenta can’t be removed?
Vaginal exam - assess if detached
What should be done if the placenta hasn’t detached?
IV access - oxytocin if excess bleeding
Manual removal under general anaesthesia
Define a post partum haemorrhage
Loss of >=500ml blood per vagina within 24 hours of delivery
What is the difference between a major and a minor post partum haemorrhage?
Minor - 500-1000ml
Major - >1000ml
Broadly, what causes a post partum haemorrhage?
Tone - failure of uterus to contract
Thrombin - coagulopathies and vascular abnormalities
Trauma
Tissue - retention of placenta
What are the risk factors for the uterus failing to contract post delivery?
Age >40 BMI >35 Asian Uterine over-distention - multiple pregnancy, macrosomia, polyhydramnios Prolonged labour Placenta praevia or abruption
What are the risk factors for thrombin/trauma related post partum haemorrhage?
Placental abruption Hypertension Pre-eclampsia Coagulopathies Instrumental vaginal delivery Epsiotomy C-Section
How should a post partum haemorrhage be managed?
Simulataneous:
Teamwork - range of specialists
Resus - 2L warmed colloids, O-ve blood until X-matched blood available
Investigations and monitoring - FBC, X match, Coag, U&E, vitals
Medication
What medication can be given in a post partum haemorrhage?
Syntocinon (1st line)
Ergometrine (1st line)
Carboprost
Misoprostol
Describe the MOA, side effects and CI’s for syntocinon
Synthetic oxytocin - stimulate myometrium contraction
SE - N&V, headache, hypertension
CI - hypertonic uterus, severe CVS disease
Describe the MOA, side effects and CI’s for ergometrine
Alpha adrenergic, dopamine and serotonin receptor action to stimulate contraction of uterus
SE - Hypertension, nausea, bradycardia
CI - Hypertension, eclampsia, vascular disease
Describe the MOA, side effects and CI’s for carboprost
Prostaglandin analogue
SE - bronchospasm, pulmonary oedema, HTN, cardiovascular collapse
CI - Cardiac/pulmonary disease
Describe the MOA, side effects and CI’s for misoprostol
Prostaglandin analogue
SE - diarrhoea
What is the definitive management for a post partum haemorrhage due to failure of the uterus to contract?
Pharmacological measures and bimanual compression
Intrauterine balloon tamponade
Surgical measures - uterine or internal iliac ligation, hysterectomy
What is the definitive management for a post partum haemorrhage due to retained placenta?
IV oxytocin
Manual removal of placenta
What is the definitive management for a post partum haemorrhage due to trauma?
Repair lacerations
If uterine rupture - repair or hysterectomy
How can a post partum haemorrhage be prevented?
Active management of 3rd stage of labour reduce risk by 60%
Vaginal - prophylactic 5-10 units IM oxytocin
C-Section - 5 units IV oxytocin
What is a secondary post partum haemorrhage?
Excessive bleeding in period between 12hr post delivery and 12 weeks post partum
How may secondary post partum haemorrhages present?
Usually spotting
Gush of blood or major haemorrhage possible
Endometritis - fever, lower abdomen pain, foul smelling lochia
Retained products - fundus felt on examination
What is lochia?
Discharge from childbirth
What can cause a secondary post partum haemorrhage?
Uterine infection - RF inc. C-Section, PROM, long labour
Retained placental fragments or tissue
Abnormal involution of placental site
How would you investigate a secondary post partum haemorrhage?
Speculum exam
High vaginal swab
Blood cultures
Pelvic USS - retained products
How is a secondary post partum haemorrhage managed?
If major then same as primary
Abx - clindamycin and metronidazole
+gentamicin in endomyometritis or sepsis
Uterotonics - syntocinon, ergometrine, carboprost etc.
What should you be aware of if surgical evacuation of retained products is required for a secondary post partum haemorrhage?
Higher risk of uterine perforation due to uterus being softer and thinner
Generally when is an emergency c-section carried out?
Failure to progress through labour
Fetal compromise
How can emergency c-sections be characterised?
1 - immediate threat to life of mother or fetus, 20-30 mins
2 - maternal or foetal compromise that isn’t immediately life threatening 60-75mins
3 - No maternal or foetal compromise but need early delivery
4 - elective
Why may an elective c-section be planned?
Usually after 39 weeks
- malpresentation
- twins or higher order pregnancy
- placenta praevia
- uterine abnormality
- cephalo-pelvic disproportion
- maternal condition - can’t cope with pregnancy
- herpes simplex in trimester 3
- HIV
- fetal weight estimated >4.5kg
What should be done before a C-Section is carried out?
G&S - usually 500-1000ml blood loss
Prescribe ranitidine - lying flat with gravid uterus increase risk of gastric content aspiration
VTE assessment - stockings and LMWH
What anaesthesia is used for a c-section?
Epidural or Spinal
General if CI to regional or category 1 emergency
How is the woman position in a c-section?
Left lateral tilt of 15 degrees - reduce risk of supine hypotension due to aortocaval compression
What is done in the operating theatre prior to incision in a c-section?
Catheter - drain bladder so less likely to be injured
Abx administered
What incision is used for a c-section?
Pfannenstiel - transverse lower abdominal
What layers must you dissect through in a C-section?
Skin
Camper’s fascia - superficial subcutaneous fat
Scarpa’s fascia - deep membranous layer of subcutaneous tissue
Rectus sheath and muscle
Abdominal peritoneum - parietal
What happens to the visceral peritoneum in a c-section?
Incised
Pushed down to reflect bladder
Where is the uterine incision in a c-section?
Lower uterine segment beneath line of peritoneal reflection
How is the baby delivered in a c-section?
Fundal pressure
De Lee’s incision (lower vertical) if lower uterine incision poorly formed
What are the final steps of a c-section after delivery?
IV oxytocin - aid delivery of placenta
Placental delivery by controlled cord traction
Uterine cavity emptied
Closure
What are the main benefits of a c-section?
Lower risk of: Perineal trauma Incontinence Uterovaginal prolapse Late stillbirth
What are the immediate complications associated with a c-section?
PPH Bladder/bowel trauma Wound haematoma Transient tachypnoea of newborn Laceration of fetus Need for hysterectomy
What are the intermediate complications associated with c-sections?
VTE
UTI - catheter
Endometritis
What are the late complications associated with c-sections?
Subferility Dehiscence of scar in next labour Regret/psychological Placenta praevia Ectopic pregnancy on scar
How successful/safe is vaginal birth after a C-Section?
Clinically safe for majority of women with 1 lower segment c-section
75% success rate
90% success rate if previous vaginal birth after c-section
What are the contraindications for vaginal birth after a c-section?
Previous uterine rupture
Classical caesarian scar
Relative CI - >2 lower segment caesarians or complex uterine scars
What are the advantages of vaginal birth after caesarian?
Shorter hospital stay
Lower risk of maternal death
Lower risk of neonatal respiratory difficulties
What are the risks to vaginal birth after a c-section?
Uterine rupture
Anal sphincter injury
Risks of waiting for spontaneous labour
How is perineal injury classified?
1st degree - injury to skin
2nd degree - injury to perineal muscles but not anal sphincter
3a - <50% of external anal spincter
3b - >50% external anal sphincter
3c - internal anal sphincter
4 - injury to perineum inc. anal sphincter and epithelium
What are the risk factors for perineal injury?
Primigravida Large babies Precipitant labour Shoulder dystocia Forceps delivery
What is the relative risk of perineal trauma to women with a history of severe perineal trauma?
Risk not increased
When/how is an episiotomy done?
If clinical need - instrumental delivery or fetal compromise
Mediolateral approach originating at vaginal fourchette directed to right
Why should a perineal tear be repaired as soon as possible?
Minimise risk of infection and blood loss
What is shoulder dystocia?
Shoulders stuck following delivery of the head
What are the types of shoulder dystocia?
Anterior shoulder impacted on maternal pubic symphysis
Posterior shoulder impacted on sacral promontory (less common)
What are the risk factors associated with shoulder dystocia?
Macrosomia Maternal diabetes Maternal BMI >30 Previous Hx of shoulder dystocia Induction of labour Prolonged labour
What are the risks of shoulder dystocia?
Fetus
- Delay in delivery - hypoxia
- Brachial plexus injury - traction to head
- Humerus/clavicle fracture
Mum
- Perineal tears
- PPH
- Pelvic floor weakness
What should be immediately done if the shoulders get stuck in delivery?
Call for help
Stop pushing
Avoid downward traction - only apply axial traction
Consider episiotomy
What is the first line management for shoulder dystocia?
McRoberts manoeuvre - hyperflex maternal hips (knees to chest)
+ suprapubic pressure - apply pressure behind anterior shoulder
What is the second line management for shoulder dystocia?
Insert hand into sacral hollow and grasp posterior arm
Internal rotation - corkscrew manoeuvre - turn shoulders 180 degrees
What is the last resort for shoulder dystocia?
Cleidotomy - fracture fetal clavicle
Symphysiotomy - cut pubic symphysis
Zavenelli - return fetal head to pelvis for C-Section
What are the types of cord prolapse?
Occult - cord drop alongside baby but may not be seen in advance
Overt - cord come before baby’s head can come out
How does fetal hypoxia occur in cord prolapse?
Occlusion - fetus press on umbilical cord occluding blood flow
Arterial vasospasm - exposure of cord to cold atmosphere results in umbilical arterial vasospasm
What are the risk factors for cord prolapse?
Breech Artificial rupture of membranes High fetal station Polyhydramnios Prematurity Long umbilical cord
How may cord prolapse present?
Fetal heart rate abnormal - subtle decelerations on contraction and bradycardia
Cord felt vaginally
Presence of blood suggest alternate diagnosis
How is cord prolapse managed?
Avoid handling cord - avoid vasospasm
Knee-chest position for mother
Manually lift presenting part by digital vaginal exam
Tocolysis - terbutaline - relax uterus and stop contractions
Delivery - usually emergency c-section
If fully dilated - can encourage vaginal/instrumental delivery
What is uterine rupture?
Full thickness disruption to uterine muscle and overlying serosa
What are the risk factors for uterine rupture?
Anything that makes the uterus wall weaker:
- previous c-section
- previous uterine surgery
- induction with prostaglandins
- multiple pregnancy
How does uterine rupture present?
Sudden severe abdominal pain - persist between contractions
Shoulder tip pain
Vaginal bleeding
Regression of presenting part
Palpable fetal parts on abdominal examination
Fetal distress
Maternal hypovolaemic shock
What are the differentials for uterine rupture?
Placental abruption
Placenta and vasa praevia - usually painless
How is uterine rupture managed?
Resuscitate
Deliver fetus by c-section
Repair uterus or hysterectomy
What is an amniotic fluid embolism?
Fetal cells/amniotic fluid enters maternal blood stream causing a reaction
How does an amniotic fluid embolus present?
Sudden onset
Hypoxia Hypotension Shock DIC Seizures
How is an amniotic fluid embolus diagnosed?
Focus on resus not diagnosis
Definitive diagnosis made post mortem - fetal squamous cells and debris found in pulmonary vasculature
How is an amniotic fluid embolus managed?
ABCDE
- high flow o2
- fluid resuscitation
How should stillbirth’s be managed?
Allow parents time and space for reflection away from normal ward
Allow to dress and spend time with child
Hospital protocols - wrap baby, offer to hold, photos, hair and palm prints
Funeral arrangements
Hospital counsellors and chaplains - comfort to families
Bereavement midwives
Consent for post mortem
Inform GP practice
What us puerperium?
6 week period following birth where body reverts to non-pregnant state
When do the CVS adaptations of pregnancy revert?
Within 2 weeks
What happens to the vagina in the puerperium?
Regain tone within 2 weeks
Initially swollen and blue
What happens to the uterus in the puerperium?
Initial - drop to size at 20 weeks
Day 12 - non-palpable
Week 6 - only slightly larger than original
What changes occur to lochia in the puerperium?
First 3 days - mostly blood and trophoblastic tissue remnants
4-12 days - Colour change from reddish-brown to yellow
What are the common complaints in puerperium and how are they managed?
Painful perineum - analgesia and sit on rubber ring
Urinary retention - catheter
Stress incontinence - pelvic floor exercises
Constipation - stool softeners
Haemorrhoids - normally disappear in few weeks
Dyspareunia - examine perineum and encourage lubricants
Backache - analgesia
Anaemia - iron
When do women require contraception after pregnancy?
After day 21
When can the progesterone only pill be taken after delivery?
Day 21 onwards with additional cover for first 2 days
Some progesterone enter breast milk but not harmful
What is the guidance on COCP after pregnancy?
Not for 6 weeks post partum if breastfeeding - unacceptable health risk
If not breastfeeding, can start after 21 days but req. 7 days additional cover
VTE risk
When can the IUD/IUS be inserted post delivery?
Within 48 hours or
After 4 weeks
What is the lactational amenorrhoea method of contraception?
98% effective contraception for fully breast-feeding women that are amenorrhoeic and <6 months post partum
What is puerperal pyrexia?
Temp >38 within first 14 days
What can cause puerperal pyrexia?
Endometritis - most common cause UTI Wound infections - perineal tear/c-section Mastitis VTE
How is puerperal pyrexia managed?
Endometritis suspected then pt. should be referred to hospital for IV Abx - clindamycin and gentamicin until afebrile for >24hrs
