Labour Flashcards
What are braxton-hicks contractions?
Intermittent contractions of the uterus from early pregnancy onwards
These increase in frequency and amplitude as labour approaches
These are irregular, low frequency, and high amplitude in character, and only occasionally painful
What are the differences between primigravid and multigravid labour?
Primigravid:
Unique psychological experience
Inefficient uterine action common, so labour lasts longer
Functional capacity of pelvis not known
Serious injury to child more common
Incidence of instrumental delivery is higher
Uterus virtually immune to rupture
Multigravid: Uterine action efficient and genital tract stretches more easily, therefore labour usually shorter Cephalopelvic disproportion is rare Serious injury to child is rare Small risk of uterine rupture
What are the pro pregnancy factors promoting pregnancy continuation?
Progesterone
Nitric oxide
Catecholamines
Relaxin
What are the pro labour factors stimulating the onset of labour?
Oestrogens Oxytocin Prostaglandins Prostaglandin dehydrogenase Inflammatory mediators
When can labour be diagnosed?
When painful uterine contractions accompany dilatation and effacement of the cervix
What are the foetal manoeuvres in labour?
Descent- head into pelvis
Flexion
Internal rotation of head - so faces sacrum
Head extension
Restitution - head turned to be back in line weigh shoulders after head delivered
Internal rotation of shoulders
Lateral Flexion - manually delivered
What is the normal position of the baby in labour?
Lie is longitudinal
Presentation is cephalic
Position is left or right occipitoanterior
Attitude is one of good Flexion
Presenting part - posterior part of anterior parietal bone
What is the attitude of the foetus?
The degree to which the head is flexed on the neck
The ideal attitude is maximum Flexion (vertex presentation)
What is a well flexed (vertex) attitude?
The head is maximally flexed so the vertex of the skull is presented
The presenting diameter is the 9.5cm and the smallest diameter of the skull, from the anterior fontanelle to below the occipit
What is deflexed attitude?
The head is not flexed so the sinciput-occipit diameter presents
What is a brow presentation?
The head is slightly extended, so the diameter from the chin to the vertex presents
Watch and wait- if does not change, then cs is indicated
What is a face presentation?
The head is hyperextended so the face presents
Can deliver vaginally if chin is anterior. If chin is posterior, may require CS
What is the position if the head during labour?
Initially occipitotransverse as the head enters the pelvis in the transverse position
Later, the head undergoes internal rotation to face the sacrum, and the position is occipitoanterior
What is a show and how often does it occur?
A blood stained mucous discharge
Occurs in two-thirds of women by the time of presentation and supports diagnosis of labour in women with regular contractions
What is pre labour rupture of membranes?
Rupture of the membranes prior to the onset of uterine contractions, after 37 weeks gestation
Occurs in 6-12% of cases
Can be managed conservatively, and 70% begin labour within 24 hours, although there is a small risk of ascending infection
Induce after 24 hours!
What is the first stage of labour?
From the onset of labour until the cervix is 10cm dilated
Latent phase - from onset of contractions until cervix is fully effaced and 4cm dilated
Active phase- 4cm to 10cm cervix dilation
What is the second stage of labour?
From full cervical dilation til the head is completely delivered
Propulsive - from full dilatation until head has descended onto pelvic floor
Expulsive - from time the mother has an irreversible desire to bear down and push until the baby is delivered
What is the third stage of labour?
From delivery of the baby until expulsion of the placenta and membranes
How is slow progress in the first stage of labour defined in primip and multips?
Primip- >12 hours duration (1cm per hour)
Multip - >7 hours duration (2cm per hour)
How is slow progress in the second stage of labour defined for the primip and Multip?
Primip- after one hour of active labour, recommend amniotomy
- after two hours, consider instrumental delivery or cs
Multip - after one hour, consider instrumental delivery or cs
What are the options for foetal intrapartum surveillance?
Intermittent auscultation
Continuous CTG
When should intermittent auscultation be used, and how often?
In a woman with no risk factors, performed for a full minute after contractions
At least every 15 mins in the first stage
Every five mins or after every other contraction in the second stage
What are the risk factors which suggest a need for CTG? Maternal and foetal
Maternal: Previous CS Cardiac problems Pre-eclampsia >42 weeks Prom Induced labour Diabetes APH
Foetal: IUGR Prematurity Oligohydramnios Multiple pregnancy Meconium stained liquor Breech presentation
What intrapartum risks require CTG?
Oxytocin augmentation Epidural analgesia Intrapartum vaginal bleeding Pyrexial Meconium staining of liquor Abnormal foetal heart rate on IA Prolonged labour
What is Meconium stained liquor and how is it managed?
Detection of the first bowel movement in the amniotic fluid- assoc with perinatal morbidity and mortality and may be aspirated by the foetus
Management:
Induction of labour if PROM
Advise CTG
If baby born with depressed vital signs, requires laryngoscopy
What are the indications for instrumental delivery?
Maternal:
Exhaustion
Prolonged second stage
Pushing not possible - paraplegia or tetraplegia
Medical indications for avoiding pushing - severe cardiac disease, hypertensive crisis, brain aneurysm
Foetal:
Foetal compromise
To control head in breech
What are the complications of operative vaginal delivery?
Forceps - maternal trauma - especially to anal sphincter
Rotational forceps - may cause spiral tears of vagina
Foetal injuries - VII palsy, skull fractures, orbital injury, intracranial haemorrhage
Ventouse - scalp lacerations and avulsions, cephalhaematoma, retinal haemorrhage
What are the differences between forceps and ventouse?
Ventouse is more likely to fail
Ventouse is more likely to cause foetal trauma
Forceps are more likely to cause maternal genital tract trauma
When should instrumental delivery be abandoned and deliver by emergency c section instead?
No evidence of progressive descent with each pull
Where delivery is not imminent following three pulls of a correctly applied instrument by an experienced operator
What are the two main types of episiotomy?
Mediolateral episiotomy - extends from the fourchette laterally to reduce the risk of anal sphincter injury
Midline episiotomy - extends from the fourchette towards the anus
What are the potential complications of episiotomy?
Bleeding Haematoma Pain Infection Scarring Dyspareunia Rarely, fistula formation
When is episiotomy recommended?
Complicated vaginal delivery - breech, shoulder dystocia, forceps, ventouse
Foetal distress
If extensive lower genital tract scarring
How are perineal tears classified?
1st degree - injury to the skin only
2nd degree - injury to the perineum involving perineum
3rd degree - injury to the perineum including the anal sphincter
4th degree - injury to perineum involving anal/rectal epithelium
What are the main indications for Caesarean section?
Repeat Caesarean section
Foetal compromise
Failure to progress in labour
Breech presentation
Maternal request is not an indication in itself but may be taken in to account
What categories determine the timing of Caesarean section?
Crash - immediate threat to the life of the woman or foetus - category 1
Urgent - maternal or foetal compromise which is not immediately life threatening - category 2
Scheduled - no maternal or foetal compromise but needs early delivery - category 3
Elective - delivery times to suit woman and staff - category 4
What are the two types of Caesarean section?
Lower uterine segment incision - most common as reduced adhesion formation and blood loss
Classical - involves vertical incision into the upper uterine segment
What are intraoperative complications of cs?
Uterine lacerations Blood loss Hysterectomy Bowel lacerations Ureteral injury
What are the post operative complications of CS?
Endometritis Wound infections Pulmonary embolism VTE UTI
What are the long term effects of cs?
Higher risk of uterine rupture
Placenta previa - scar tissue means placenta may adhere in the wrong place
Placenta accreta - placenta won’t come off uterus
Antepartum stillbirth
What can cause pre labour rupture of membranes?
Idiopathic Infection Polyhydramnios Multiple pregnancy Mal presentations
What are the clinical features of chorioamnionitis?
Fetal tachycardia Maternal tachycardia Maternal pyrexia Rising leucocyte count Rising CRP Irritable or tender uterus
How long does it take to deliver a placenta before it is considered retained?
A placenta is retained if it is not delivered within 30 mins of baby if third stage is actively managed
One hour if it is passively managed
May require manual removal of placenta in theatre
What is active management of the third stage?
Syntometrine or oxytocin
Controlled cord traction
What is placenta accreta, increta and percreta?
Placenta is not separated from the myometrium
Placenta accreta- placental villi attached to myometrium
Placenta increta - villi invade myometrium
Placenta percreta - villi pass through myometrium and involve other viscera
What is primary post partum haemorrhage
Blood loss of 500ml or more from the genital tract occurring within 24 hours of delivery
What is secondary post partum haemorrhage?
Excessive loss occurring between 24 hours and six weeks after delivery
What are the causes of primary PPH?
Uterine atony - failure of uterus to contract after delivery - often due to twins, polyhydramnios, high parity, retained products
Genital tract trauma
Coagulation disorders
Abnormal placental site - placenta previa, accreta
What are the antenatal risk factors for PPH?
Previous PPH Previous retained placenta Para four or more APH Over distension of the uterus Maternal age and bmi
What is a transverse or oblique lie?
When the axis of the foetus is across the axis of the uterus
Common before term, but occurs in 1% after 37 weeks
What is unstable lie?
When the lie is changing, usually several times a day, and may be transverse or longitudinal, and cephalic or breech presentation
What are the causes and associations of abnormal foetal lie?
Multiparity (lax uterus) Polyhydramnios Uterine abnormalities eg. Fibroids Placenta previa and obstructions to pelvis Foetal abnormalities Multiple pregnancy
What are the risks of abnormal lie?
Obstructed labour and potential uterine rupture
Membrane rupture risks cord prolapse, as with normal longitudinal lie, the presenting part prevents descent if the cord through the cervix
How is unstable lie managed?
Admit to hospital from 37 weeks so that CS can be carried out if labour starts
Lie may stabilise
If lie does not stabilise, a CS is performed at 41 weeks
If lie is stable but not longitudinal, a CS should be considered at 39 weeks
What is the medical management of PPH due to atomic uterus?
Empty bladder Oxytocin - ergetrine Massage uterus through abdominal wall Carboprost for further bleeding B- lunch suture - to compress uterus Hysterectomy as last resort
What are the indications for elective section?
Previous CLASSIC section
Failed ECV
Placenta previa
Multiple pregs if first twin is not cephalic
Reducing risk of transmission of infection - eg HIV and herpes outbreak
Which forceps are rotational, and which have a fixed curve!
Kiellands - rotational
Neville Barnes - fixed cephalic curve
