Intrapartum Care 2 Flashcards
What is the lie of the baby?
The way the long axis of the fetus is facing
What four terms can be used to describe a baby’s lie?
1) Cephalic - head down and bum towards the fundus of the uterus
2) Breech - bum of feet down with the head towards the fundus
3) Transverse - the baby is lying horizontally in the uterus
4) Oblique - the baby is on the diagonal
What is the presentation of the baby?
Which part of the fetus is at the pelvic brim
What three terms can be used to describe a baby’s presentation?
1) Face
2) Brow
3) Breech
What is the position of the baby? What is normal?
The way in which the presenting part is position in relation to the maternal pelvis
Normal = occipito-transverse at the pelvic brim rotating to the occipito-anterior at the pelvic floor
What is a malposition?
When the head coming first does not rotate from the occipito-transverse position to the occipito-anterior
Or it might rotate incorrectly and present occipito-posterior
What is the cause of breech presentation?
1) High ratio of amniotic fluid to fetal size allowing freer movement - eg <32 weeks or polyhydramnios
2) Extended legs prevent flexion and stop further turning
3) Multiple pregnancy
4) Something filling lower segment eg placenta praevia or fibroids
5) Fetal malformations preventing cephalic presentation eg hydrocephaly
What are the 3 types of breech presentation?
A - frank / extended breech
B - Complete / flexed breech, both knees flexed
C - Footling breech, either single or double with both hips extended. Occurs in very small babies
Which type of breech is most common?
A - frank / extended breech
What is face presentation associated with?
Anencephaly
What is a brow presentation?
Presenting with the supra-orbital ridges and the bridge of the nose
Usually palpable on VE
Which is the least favourable of the malpresentations?
Brow presentation
What is the management of breech presentation?
External cephalic version (ECV)
- Offered from 36wks in nulliparous women and 37wks in multiparous women (do not bother in placenta praevia as they will require CS anyway)
What is the method of ECV?
Listen to the fetal HR immediately before and after the procedure
Administer SC salbutamol or ritodrine as a tocolytic (uterine relaxant)
Disengage the breech from the pelvis, and pushing the head and breech in opposite directions, slowly rotate the baby through 180 degrees
Which breeches are more likely to turn in ECV?
Flexed breech (B) more likely to turn than extended breech (A)
What are the success rates of ECV?
30% for nulliparous
50% for multiparous
What are some risks of ECV? (6)
Pain Transient bradycardia Prolonged bradycardia Abruption (<1%) Emergency LSCS Materno-foetal haemorrhage (give anti-D if Rh-ve mother)
What factors are unfavourable for a vaginal breech delivery?
1) Inadequate pelvic diameters - requires >11cm AP and transverse
2) Foetal weight >3.5kg
3) Footling breech (C)
4) Other CI to vaginal birth eg placenta praevia, compromised foetus
5) Prev CS
6) Hyperextended fetal neck
What are some risks of vaginal breech delivery?
1) 3x inc risk of fetal hypoxia
2) Risk of head entrapment
3) Risk of intracranial damage
4) May lead to emergency CS
What is the management of a transverse lie?
<36 weeks = presentation is usually self correcting
> 37 weeks (multiparous) or >38wk (nulliparous) = admission to hospital for ECV attempts daily
If still transverse lie at term
- Stabilising induction
- Elective CS (usually safer, reduced risk of cord prolapse)
What is a stabilising induction?
ECV done in labour ward
Foetus’s head held over brim of pelvis and high membrane rupture performed
Amniotic fluid escapes and the head often sinks into the pelvis
How may a baby be malpositioned?
Occipito-posterior or occipito-transverse
What is the management of an occipito-transverse position?
Will not deliver spontaneously
Give epidural
Instrumental delivery with rotational forceps - Kielland’s straight forceps
- CI in foetal distress
IV symptometrine with head crowning as risk of PPH is inc
- Deliver placenta promptly after foetus born
Inc risk of perineal tears and injury to anal sphincter and rectal mucosa
Inc risk of foetal mortality (hypoxia and birth trauma) and morbidity (intracranial haemorrhage)
What are some complications of twin delivery?
PPH more common
Prolapse of umbilical cord more common
Mechanical collision of lead parts as they both enter pelvis (rare)
Delay in delivery of 2nd twin leads to higher mortality
What is the management of labour of twin delivery?
Plan for hospital delivery
Ensure first twin is longitudinal - both twins lie longitudinally 90% time, and the first twin is cephalic 90% time
Check for cord prolapse when membranes rupture - often early in labour
Progress is often uneventful
CTG
Epidural useful - allows any necessary manoeuvring of 2nd twin
When can syntometrine be given in twin delivery?
Ensure it is not given inadvertently after 1st twin delivery - would compromise blood supply of 2nd twin
Can give with delivery of 2nd twin and continue oxytocin IV for another hour
How soon after twin 1 should twin 2 be born? Would should happening following 1st twin delivery?
Ideally within 60 minutes of the first
If uterus does not restart spontaneous contractions after 5 mins, use IV oxytocin
Rupture membranes of 2nd sac
Deliver placenta promptly - retained placenta and PPH are common
What 5 conditions must be met for an instrumental vaginal delivery?
1) Adequate analgesia
- Epidural or pudendal + field block
2) The fetal head should not be more than 1/5 palpable in the abdo
3) Full cervical dilatation
4) Presenting part at the ischial spines of below with accurate knowledge of the fetal head position (OA / OT / OP)
5) Empty bladder via catheter
What is a ventouse extraction?
aka vacuum extraction
Suction cup used to get purchase of fetal head, allowing traction to be applied
What are some indications for a ventouse extraction? (4)
1) Delay in 2nd stage - often with OP or OT presentation
2) Maternal exhaustion
3) Compound presentations (hand or foot lies alongside the head)
4) High head of twin 2
What are some contraindications for a ventous extraction? (3)
1) Malpositions - esp face presentation / breech
2) Prematurity (<36wks)
3) Maternal HIV / hep B
What are two types of forceps?
1) Non-rotational
2) Rotational
Describe non-rotational forceps and when they are used
Grip the head in whatever position it is in and allow traction
Only suitable when head is in OA position
Have a cephalic curvature for the head and a pelvic curve which follows the sacrum
Describe rotational forceps and when they are used
Have no pelvic curve and are straight handled to allow a malpositioned head (OT / OP) to be rotated to the OA position before applying traction
What biophysical signs may indicate fetal hypoxia?
Tachy / bradycardia
Loss of baseline variability
Late decels
What biochemical signs may indicate fetal hypoxia?
pH <7.15 on FBS
How is the risk of a perineal tear minimised during a forceps delivery?
Episiotomy (mediolateral recommended)
However it may extend
What may cause urinary retention following a forceps delivery?
Thought to be due to oedema at bladder neck
What is the classic approach of CS and when may it be performed?
Classic approach = vertical incision through upper segment
Performed if lower segment unapproachable because of fibroids, or baby in transverse lie or very small baby (24-28wks)
What are some benefits of LSCS vs classic approach? (3)
Fewer post-op complications
Healing of scar better
Lower risk of rupture in future pregnancies
What analgesia is usually used during a CS?
Spinal block
GA in emergency (if insufficient time to do a spinal block)
What precautions are taken prior to a CS?
Haemorrhage:
- Group and save with rapid access to 2 units
- All labour wards must have 2 units of O-negative available at all times
Infection:
- Prophylactic abx (usually cephalosporin)
What is shoulder dystocia?
Occurs when shoulders do not spontaneously deliver after the head
Anterior shoulder becomes trapped behind or above the pubic symphysis whereas the posterior shoulder may be in the hollow of the sacrum
What are some risk factors for shoulder dystocia? (7)
1) Prev should dystrocia
2) Prev baby >4.5kg
3) Big baby clinically or on USS (abdo circumference >95th centile)
4) Maternal DM (more likely to have big baby)
5) Obese mother (BMI >30)
6) Secondary arrest in labour augmented by syntocinon
7) Prolonged 2nd stage of labour
What are some signs of shoulder shoulder dystocia? (3)
1) Fetal chin pulls back against perineum
2) No external rotation of head (restitution)
3) Anterior shoulder fails to deliver with contraction
What is the management of shoulder dystocia?
Senior help
Change maternal position = McRobert’s manoeuvre
Episiotomy (right medio-lateral)
Manually rotate shoulders
Delivery the posterior arm
Symphysiotomy
What maternal positions can be tried when managing shoulder dystocia?
1) McRobert’s manoeuvre = flatten bed, retract the woman’s knees onto her chest as far as possible and apply gentle traction to the fetus - this straightens the sacrum and maximises pelvic diameter
2) Place woman on all fours
3) Return to supine and place external pressure just above the pubic symphysis
Try each of these manoeuvres once for 30s each
What is a symphysiotomy?
An incision of the fibro cartilage through the symphysis pubis
Performed in labour to enlarge the transverse diameter of the pelvis
What are some fetal complications of shoulder dystocia? (4)
1) Erb’s palsy = brachial plexus injury
2) Cerebral palsy from hypoxia
3) Fractured humerus / clavicle
4) Neonatal death
What is considered to be an antepartum haemorrhage?
Bleeding from the genital tract after 24 weeks of pregnancy
Before 24 weeks = threatened miscarriage
What is primary and secondary postpartum haemorrhage?
Primary = bleeding >500ml from genital tract in the 24hrs post delivery
Secondary = excessive bleeding from genital tract any time between 24hours and 6 weeks post delivery
What are some causes of primary PPH?
4 x Ts
Tone - uterine atony
Trauma - genital tract trauma
Tissue - retained products of conception
Thrombin - abnormal clotting
What is a placental abruption?
When part / all of the placenta separates from the uterine wall before delivery of the fetus, after 24wks gestation
What are some risk factors of placental abruption? (12)
1) Prev abruption
2) Pre-eclampsia
3) IUGR
4) Non-cephalic presentations
5) Polyhydraminous
6) Advanced maternal age
7) Multi-parity
8) Low BMI
9) Intrauterine infection
10) Abdo trauma
11) Smoking / drug misuse (cocaine and amphetamines)
12) PROM
How may a placental abruption present?
1) Painful bleeding - pain due to blood behind the placenta and in the myometrium. Blood often dark
2) Degree of vaginal bleeding not always consistent with severity of blood loss as not all blood will escape from the uterus
3) Tachycardia indicates severe blood loss - may have maternal collapse
4) Uterus often tender and contracting - labour normally ensues
- In severe cases the uterus may feel very hard and the fetus is difficult to palpate
How is placental abruption usually diagnosed?
Clinical diagnosis
USS is mostly done to rule out placenta praevia
What investigation is done if woman is Rhesus negative and has a placental abruption?
Kleihauer test - detects foetal blood cells in maternal circulation
What is the management of delivery in a placental abruption?
Stabilise mother first
If fetal distress on CTG = urgent CS
If no fetal distress but gestation is >37 weeks = IOL by ARM. Continuous fetal monitoring and CS if fetal distress ensues
If fetus is dead, coagulopathy is likely = blood products given and IOL
If there is no fetal distress, the pregnancy is preterm and the degree of abruption appears to be ‘minor’ = give steroids and monitor on antenatal ward
- Requires serial USS for fetal growth
How is primary PPH classified?
Blood loss >500ml for NVD or >1000ml for CS
Minor = 500 - 1000ml Major = >1000ml
(Moderate = 1000 - 2000ml, severe = >2000ml)
What are the risk factors for uterine atony?
Maternal factors - 40+ years, BMI >35, Asian
Uterine over-distention - multiple pregnancy, polyhydramnios, foetal macrosomia
Muscle fatigue - induction, prolonged labour
Placental problems - placenta praevia, placental abruption, previous PPH
Obstetric medications - anaesthetics, magnesium sulphate, nifedipine, terbutaline
What can affect tissue leading to PPH?
1) Retained products - lower areas of uterus contract, so placenta is trapped and cannot be delivered
2) Partly separated placenta
3) Placenta praevia / placenta accreta / placental abruption
What can lead to trauma causing PPH?
1) Genital tract trauma - tears of uterus, cervix, vagina pr perineum (approx 20%)
2) Increased risk with instrumentation and shoulder dystocia
What can affect thrombin causing PPH?
1) Clotting disorders
2) Maternal infection / pre-eclampsia with DIC
3) Warfarin / LMWH
How can PPH be prevented?
Uterotonic drugs eg oxytocin in the 3rd stage of labour reduces the incidence of PPH by 60%
What is the management of PPH caused by uterine atony?
Bimanual compression to stimulate uterine contraction - insert hand into vagina and form fist inside the anterior fornix to compress anterior uterine wall whilst other hand applies pressure on abdomen at posterior aspect of the uterus
Use uterotonic drugs to increase uterine myometrial contraction e.g. syntocinon, ergometrine, carboprost, misoprostol
Surgical
- Intrauterine balloon tamponade
- Haemostatic suture around uterus
- Bilateral uterine or internal iliac artery ligation
- Hysterectomy
What investigations should be done for secondary PPH?
HVS and endocervical swab to check for infection
FBC (and cross match in severe cases)
Pelvic USS - good at excluding retained placental tissue but differentiation of blood clot vs retained placental tissue is poor
What is the management for secondary PPH?
Antibiotics + Uterotonics = mainstay of treatment
If bleeding is heavy - ERPC (Evacuation of retained products of conception)
What is an endocrine complication of PPH?
Sheehan syndrome
What is the pathophysiology of sheehan syndrome?
Blood loss during a PPH can mean there is not enough blood remaining to supply the pituitary gland adequately (which has high oxygen demand due to lactotrophins which have increased in size and are releasing prolacint o stimulate lactation in post-partum period)
It therefore starts to become ischaemic and necrosed
= Death of lactorophs (cells in pituitary gland which produce prolactin), as well as cells producing many types of hormones
What collection of symptoms are seen in sheehan syndrome?
Lack of prolactin = agalactorrhoea
Lack of FSH and LH = amenorrhoea
Lack of TSH = low BP, cold intolerance and weight gain
How is sheehan syndrome diagnosed?
Low hormone levels in blood
MRIs and CTs can show structural changes in pituitary gland which can shrink
- Sella turcica = pituitary ring sign
What is a uterine inversion?
When the fundus of the uterus inverts into the uterine cavity
It usually occurs due to some kind of traction on the placenta (incorrectly managed third stage)
More likely in grand multips
How may a uterine inversion present?
Pain
Haemorrhage
Shock - vasovagal, pale, clammy, bradycardic, hypotensive
Mass in the intriotus - may be able to see on examination
What is the management of a uterine inversion?
The shock will reverse itself when the uterus is re-aligned = this should be a priority
Start with a brief manual attempt to push the fundus back up via the vagina
If this is not possible, GA should be given and the fundus should be reverted by pumping several litres of warm saline into the vagina past a clenched fist in the intriotus
What is the most common cause of severe sepsis resulting from a mid-trimester rupture of membranes?
Strep A
What is one of the leading cause of sepsis in the post-natal period?
Retained products of conception
How is an amniotic fluid embolus often diagnosed?
Usually a diagnosis of exclusion or made on post mortem
When is an amniotic fluid embolus most likely to occur?
Just after ARM
How may an amniotic fluid embolus present?
Collapse
DIC
Unaccountable bleeding
What is the management of an amniotic fluid embolus?
Early transfer to ITU for renal and inotropic support
Senior help
Correct any clotting problems
What two groups of women are most at risk for a uterine rupture?
1) VBAC
2) Multiparous women who are on uterine stimulants
How may a uterine rupture present?
1) Fresh vaginal bleeding
2) Haematuria
3) Fetal distress
4) Constant, sever pain that may even break through an epidural
5) Shock
6) Cessation of contractions
What is the management of a uterine rupture?
1) ABCDE
2) IV access and resuscitation
3) Immediate laparotomy to salvage baby and repair damage / possible hysterectomy
What is a cord prolapse?
When the cord is present before the presenting part
Occurs when the membranes rupture and the presenting part does not fill the pelvic well
The umbilical cord may be carried by the flow of amniotic fluid
The cord could remain in the vagina or prolapse out of the introitus
What are some complications of cord prolapse?
1) Insults on the cord can lead to reduction in fetal blood flow and fetal death
2) Cord can spasm due to colder environment affecting fetal blood flow
3) Cord can be mechanically compressed between presenting part and bony pelvis
How is a cord prolapse diagnosed?
Sudden change in fetal heart rate or rhythm (eg variable decels) soon after membrane rupture
Or loops of cord appear at the vulva / palpated on VE
How is cord prolapse managed?
Immediate delivery:
- CS if <9cm dilated
- Ventouse if >9cm dilated and favourable cephalic presentation
- Ventouse or forceps if fully dilated
If immediate delivery not possible:
- Keep cord warm and moist (place back into vagina) and avoid compression between presenting part and pelvis
Insert a foley catheter can be used to put 500ml into maternal bladder = acts as a cushion to prevent cord compression
Give tocolytic to reduce contractions - terbutaline 0.25mg slow IV
What is the HELPERR mneumonic for management of shoulder dystocia?
H - immediately call for help
E - episiotomy (evaluate if necessary)
L - legs (McRobert’s manoeuvre)
P - pressure on suprapubic region
E - enter (woodscrew and reverse woodscrew manoeuvres)
R - remove posterior arm
R - roll into hands and knees and repeat manoeuvres
What are the classification of perineal tears?
1st degree - injury to the perineal skin only
2nd degree - tear involving perineal muscles but not anal sphincter
3rd degree - tear involving anal sphincter complex
3a) <50% external anal sphincter
3b) >50% external anal sphincter
3c) Internal anal sphincter also affected
4th degree - involving anal sphincter and anal epithelium
NB any uncertainty as to the degree of tearing, it is safer to categorise it as a higher degree
What is an episiotomy?
A surgical incision made in the perineum to facilitate delivery
When is an episiotomy usually performed?
Forceps to help avoid perineal tears
Shoulder dystocia
How is an episiotomy usually performed?
Usually done at 45 degrees to from the posterior fourchette - eg right mediolateral
What is the benefit and disadvantage of a right mediolateral episiotomy?
Benefit - reduces risk of severe perineal tear (50% relative risk reduction for every 6 degrees away from the perineal midline)
But associated increased blood loss
