Obstetrics Flashcards
How should a low risk woman be monitored during labour?
intermittent fetal heart rate auscultation with Doppler or Pinnard
once every 15 minutes for a whole minute
After a contraction
Listen for rate, accelerations and deceleration
When could continuous CTG monitoring be indicated during labour?
maternal pulse over 120 beats/minute on 2 occasions 30 minutes apart
temperature of 38°C or above on a single reading, or 37.5°C or above on 2 consecutive occasions 1 hour apart
suspected chorioamnionitis or sepsis
pain reported by the woman that differs from the pain normally associated with contractions
the presence of significant meconium (as defined in ongoing assessment)
fresh vaginal bleeding that develops in labour
severe hypertension: a single reading of either systolic blood pressure of 160 mmHg or more or diastolic blood pressure of 110 mmHg or more, measured between contractions
hypertension: either systolic blood pressure of 140 mmHg or more or diastolic blood pressure of 90 mmHg or more on 2 consecutive readings taken 30 minutes apart, measured between contractions
a reading of 2+ of protein on urinalysis and a single reading of either raised systolic blood pressure (140 mmHg or more) or raised diastolic blood pressure (90 mmHg or more)
confirmed delay in the first or second stage of labour
contractions that last longer than 60 seconds (hypertonus), or more than 5 contractions in 10 minutes (tachysystole)
oxytocin use.
When is someone ‘in labour’
> =4cm dilation
regular contractions
What is defined as delay in teh first stage of labour
less than 2cm dilation in 4 hours
wing in the progress of labour for multip
changes in the strength, duration and frequency of uterine contractions
What is defined as delay in the second stage of labour
For a nulliparous woman:
diagnose delay in the active second stage when it has lasted 2 hours
suspect delay if progress (in terms of rotation and/or descent of the presenting part) is inadequate after 1 hour of active second stage
For a multiparous woman:
diagnose delay in the active second stage when it has lasted 1 hour
suspect delay if progress (in terms of rotation and/or descent of the presenting part) is inadequate after 30 minutes of active second stage.
What do you look for when assessing a CTG trace?
baseline HR
variability
deceleration
acceleration
What would be reassuring, non-reassuring or abnormal for a baseline heart rate on a CTG
reassuring - = 110-160 bpm
non-reassuring - 100-109 or 161-180
abnormal = <100
What would be reassuring, non-reassuring or abnormal for variability on a CTG
reassuring - = 5-25
non-reassuring = less than 5 beats/minute for 30 to 50 minutes
more than 25 beats/minute for 15 to 25 minutes
abnormal = less than 5 beats/minute for more than 50 minutes
more than 25 beats/minute for more than 25 minutes
sinusoidal.
What would be reassuring for decelerations on a CTG
reassuring:
no decelerations
early decelerations
variable decelerations with no concerning characteristics (see below) for less than 90 minutes
What makes a CTG normal?
all reassuring features
What makes a CTG suspicious?
one non-reassuring feature, two reassuring
What makes a CTG pathological?
one abnormal or two non-reassuring
What should be done if a CTG is pathological?
exclude acute events - cord prolapse, placental abruption, uterine rupture
conservative measure - mobilise, IV fluids
senior review
digital fetal scalp stimulation
What is expected to happen to the fetal heart rate with fetal scalp stimulation
it is expected to increase! Shows that the baby is healthy
If fetal scalp stimulation does not increase the baseline fetal heart rate, what should be done
senior!!!
fetal blood sample
expediate delivery
How should a fetal blood sample be taken
woman lies in left laterla position
do not take during or immediately after a decerlation
What are the normal, borderline and abnormal parameters for fetal pH on fetal blood sampling
normal - >=7.25
borderline 7.21-7.24
abnormal <=7.20
What are the normal, borderline and abnormal parameters for fetal lactate on fetal blood sampling
normal - <=4.1
borderline 4.2-4.8
abnormal >=4.9
What should be done if a fetal blood sample is abnormal?
expediate delivery!
caesarean or instrumental delivery
What should be done if a fetal blood sample is normal?
If no accelerations in response to fetal scalp stimulation,
consider taking a second fetal blood sample no more than 1 hour later
if this is still indicated by the cardiotocograph trace.
What should be done if a fetal blood sample is borderline?
If no accelerations in response to fetal scalp stimulation,
consider taking a second fetal blood sample no more than 30 minutes later
if this is still indicated by the cardiotocograph trace.
What is fetal distress
compromise of fetus due to inadequate oxygen or nutrient supply due to uteroplacental insufficiency
What are the pathophysiological reasons for fetal distress
uteroplacental vascular disease decreased uterine perfusion intrauterine sepsis decreased fetal reserves cord compression
What are the risk factors for fetal distress
history of Stillbirth. Intrauterine growth restriction (IUGR). Oligohydramnios or polyhydramnios. Multiple pregnancy. Rhesus sensitisation. Hypertension. Obesity. Smoking. Diabetes and other chronic diseases. Pre-eclampsia or pregnancy-induced hypertension. Decreased fetal movements. Recurrent antepartum haemorrhage. Post-term pregnancy. Maternal age over 35 years, and particularly over 40,
What are the features of fetal distress
decreased fetal movements
slowing or stop of growth of serial symphysis fundal height
abnormal USS parameters - IUGR, macrosomia
doppler USS abnormality <34w
abnormal antenatal or intrapartum CTG
fetal scalp sampling - raised lactate, acidic pH
meconium stained liquor
How is suspected fetal distress managed?
antenatal - induction/c-section/defer delivery. weight up risks of preterm delivery
during delivery - expediate delivery within 30 minutes if risk to life.
how is HTN during pregnancy defined?
diastolic >=90 mmHg or on two occasions more than 4 hours apart,
and/or
diastolic >110 mmHg
What are the parameters for mild, moderate and severe HTN in pregnancy
mild: >=140/90
moderate >= 150/100
severe >= 160/110
what is chronic hypertension in pregnancy
present at <20 weeks
As blood pressure tends to fall during the first and second trimesters, a woman with a high blood pressure before weeks’ gestation can be assumed to have pre-existing hypertension.
what is gestational HTN
new HTN at >20 weeks
WITHOUT proteinuria
Define pre-eclampsia
> 20 weeks gestation
+ HTN
+ proteinuria - >300mg in 24hrs or >30 mg/mmol in a urinary protein/creatinine sample
Define eclampsia
seizures/convulsions on top of a background of pre-eclampsia
What does HELLP stand for?
haemolysis, elevated liver enzymes, low platelets
What puts a woman at high risk of pre-eclampsia
one of: hypertensive disease during a previous pregnancy. CKD Autoimmune disease Type 1 or type 2 diabetes. Chronic hypertension. Thrombophilia.
two of: first pregnancy. >= 40 years Pregnancy interval of more than 10 years. BMI >= 35 Family history of pre-eclampsia. Multiple pregnancy.
How are women at high risk of pre-eclampsia managed
75mg aspirin from 12 weeks until birth
dipstick urine and check BP at each visit
give info on symptoms of pre-clampsia and who to contact if they develop
What is the pathophysiology of pre-eclampsia
placental insufficiency due to incomplete remodelling of the spiral arteries
leads to high resistance low flow uteroplacental circulation
leads to maternal inflammatory response and maternal vascular endothelial dysfunction
causes hyper permeability, thrombophilia and hypertension (compensation for poor uteroplacental flow)
What are the symptoms of pre-eclampsia
asymptomatic! headache - severe frontal visual problems - blurring, double vision, halos, flashing lights breathing difficulties - due to pulmonary oedema epigastric/RUQ pain vomiting reduced fetal movements oedema
Why do women get epigastric/RUQ pain in pre-eclampsia
due to hepatic capsule distension or infarction
What defines severe pre-eclampsia
BP > 160/110 + proteinuria > 0.5 g/ day
or
BP > 140/90 mmHg + proteinuria + symptoms.
When should a woman be admitted to hospital with pre-eclampsia
Raised BP (≥ 140/90 mm Hg) with proteinuria ≥+1.
Systolic BP ≥160 mm Hg.
Diastolic BP ≥100 mm Hg.
Any clinical symptoms or signs of pre-eclampsia.
What are the maternal complications of pre-eclampsia or eclampsia
haemorrhagic stroke ARDS pulmonary oedema HELLP AKI DIC death
increased risk of HTN in future
What are the fetal complications of pre-eclampsia
prematurity IUGR intrauterine death placental abruption IRDS
What investigations need to be done in suspected pre-eclampsia
urine dip, BP
FBC, U+E, LFT, clotting
24 hour urine protein, P:Cr ratio
ultrasound assessment of fetal growth and the volume of amniotic fluid, and Doppler velocimetry of umbilical arteries.
CT/MRI head if any focal neurology or coma
How should a women with pre-eclampsia be monitored and treated?
mild: BP QDS. FBC, U+Es, LFTs twice a week
moderate: BP QDS. FBC, U+Es, LFTs three times a week, labetalol
severe, BP >QDS, labetalol, FBC, U+Es, LFTs three times a week
What needs to be monitored in a woman with pre-eclampsia
BP protein in urine FBC U+E LFT clotting USS fetus CTG
Which antihypertensives are used in pre-eclampsia
labetalol - first line
nifedipine
methyl-dopa
What class of drug is labetalol? What are the side effects?
Beta-blocker.
Postural hypotension, fatigue, headache, nausea and vomiting, epigastric pain.
What class of drug is nifedipine? What are the side effects?
Calcium channel blocker.
Peripheral oedema, dizziness, flushing, headache, constipation.
What class of drug is methyl-dopa? What are the side effects?
Alpha-agonist.
Drowsiness, headache, oedema, GI disturbances, dry mouth, postural hypotension, bradycardia, hepatotoxicity.
What is the target BP in treatment of pre-eclampsia
<150/100
What is the definitive management of pre-eclampsia
delivery of the placenta
how is the third stage of labour managed in pre-eclampsia? What should not be used?
give syntocinon
syntometrine and ergometrine should not be used as they increase BP
When are women no longer at risk of developing eclampsia?
five days after delivery
What are the features of eclampsia
generalised tonic-clonic seizure
lasts 60-75 seconds
in presence of pre-eclampsia
What are the risks to the fetus during eclampsia
fetal distress
fetal bradycardia
What is the differntial diagnosis for a seizure occuring in pregnancy
eclampsia hypoglycaemia epilepsy stroke - haemorrhagic or ischaemic meningitis head trauma
What are the five principles in the management of eclampsia and what do they involve?
- resuscitation - A to E, lie in left lateral position
- stop seizures - use magnesium sulphate. continue for 24 hours after delivery. CTG MONITORING
- BP control - IV labetalol or hydralazine. CTG MONITORING
- delivery - only when BP, seizures and hypoxia in mum are stabilised, no matter the level of fetal distess. Mum needs to be in HDU for at least 24 hours after delivery
- fluid balance - be careful to prevent pulmonary oedema or AKI
How should a mother be cared for post delivery if pre-eclampsia was present
BP QDS and ask about any symptoms of pre-eclampsia
FBC, U+E, LFTs 72 hours after birth
discharge to community midwives when BP <150/100
reduce antihypertensives when BP <130/80
monitor BP in community
BP and urine dip at 6 weeks
How is PPH defined?
loss of >500ml of blood after delivery
What is teh difference between primary and secondary PPH
primary = within 24 hours of delivery secondary = >24 hours to 6 weeks after delivery
What is the difference between minor primary PPH and major primary PPH
minor = <1000ml major = >1000ml
What are the four broad causes of primary PPH
trauma
tone
tissue
thrombin
What types of trauma can cause primary PPH
damage to the reproductive tract during delivery
forceps/ventouse
episiotomy
C section
What problem with tone can cause primary PPH
uterine atony
= failure to contract adequately due to lack of tone
What are the risk factors for uterine atony
maternal:
>40y
BMI >35
asian
uterine overdistension:
multiple pregnancy
polyhydraminos
fetal macrosomia
labour:
induction
prolonged
placental:
praevia
prev PPH
placental abruption
What problem with tissue can cause primary PPH
retained placental tissue
prevents the uterus contracting
What are the features of a women with primary PPH
bleeding!
dizziness, palpitations, SOB
increased RR, increased HR, low BP, increased cap refill
What might you look for on examination of a women with primary PPH
abdomen - ?uterine rupture
speculum - sites of local trauma
placenta - any parts missing
What are the four main principles of management of primary PPH
communication
resuscitation
monitoring
stop bleeding!
What aspects of communication need to be considered when managing primary PPH
SENIOR HELP
contact senior obstetrics, senior midwife, anaesthetist
contact blood bank
MAJOT HAEMORRHAGE PROTOCOL
What aspects of resuscitation need to be done when managing primary PPH
A-E 2x 14G cannulae crystalloid - 2 litres warmed Hartmann's until blood arrives o neg or cross matched blood recombinant factor VIIa
What aspects of monitoring need to be done when managing primary PPH
minor:
BP and pulse every 15 mins
FBC, G+S, coag
major:
continuous monitoring
FBC, G+S, coag, crossmatch four units, U+E, LFTs
?arterial line and ITU
What can be done to stop primary PPH due to uterine atony
bimanual compression
syntocinon/oxytocin 5 units IV slowly
ergometrine (unless HTN)
misoprostol
balloon tamponade haemostatic brace suturing, ligation uterine arteries ligation internal iliacs selective embolisation hysterectomy
What can be done to stop primary PPH due to trauma
repair laceration
repair uterine rupture
What can be done to stop primary PPH due to retianed placenta
manual removal of placenta
IV oxytocinon after removal
prophylactic Abx
How can primary PPH be prevented?
active management of the third stage of labour
5-10 units of IM oxytocin if vaginal delivery
5 units IV oxytocin if c section
What are some causes of secondary PPH
endometritis
retained placental tissue
abnormal involution of the placental site - inadequate closure and sloughing of spiral arteries
trophoblastic disease
What are the features of endometritis
PV bleed fever pain offensive lochia dyspareunia dysuria malaise suprapubic tenderness tender adnexae
What are the features of retained placental tissue
PV bleed
pain
elevated fundus - feels boggy
What investigations need to be done in secondary PPH
FBC U+E CRP coag G+S
blood culture, high vaginal swabs
USS - for placental tissue
How should secondary PPH be managed
?sepsis needs admission
antibiotics - piperacillin and tazobactam if severe, coamoxiclav or metronidazole if less severe
if retained placental tissue, contact obstetrician for curretage
What is an antepartum haemorrhage
PV bleed from >24 weeks gestation up to when the second stage of labour is completed
What could cause an antepartum haemorrhage
placenta praevia
placental abruption
vasa praevia trauma domestic violence uterine rupture infection eg, candida, chlamydia, BV marginal placental bleed local lesions - ectropion, polyps
What is vasa praevia
fetal blood vessels run near the internal cervical os in the fetal membranes
ROM leads to rupture of the umbilical cord vessels
leads to PV bleed and fetal compromise
What happens in placental abruption
rupture of the maternal vessels within basal layer of endometrium
blood accumulates and splits placental attachment from basal layer
part or all of the placenta separates from the wall of the uterus prematurely
detached portion of placenta is unable to function
leads to fetal compromise
What is the difference between revealed and concealed placental abruption
revealed = bleeding tracks down and drains through cervix. PV bleed
concealed - blood remains within the uterus. clot forms retroplacentally. can still causes systemic shock!
What are the risk factors for placental abruption
*previous placental abruption pre eclampsia HTN abnormal fetal lie polyhydraminos abdominal trauma - RTA, DV, ECV smoking drugs bleeding in first trimester thrombopilia multiple pregnancy
What are the key features of placental abruption
PV BLEED! constantly painful uterus woody, hard uterus on palpation painful on palpation of uterus shock fetal distress
What investigations should be done in antepartum haemorrhage
CTG
FBC U+E LFT clotting G+S cross match 4 units
Kleihauer test
USS
What is the Kleihauer test?
blood test to determine the amount of feto-maternal haemorrhage and therefore the dose of anti-D needed
What is the management of placental abruption
A - AIRWAY
B - high flow o2
C two large bore cannulae, bloods warmed crystalloid fluids until blood arrives cross matched blood ?FFP, cryoprecpitate
Decide on delivery!
C section if maternal compromise or fetal distress
ROM and vaginal delivery if fetal death occurs
if bleeding settles, delivery is not imminent. Can give steroids for fetal surfactant
What is placenta praevia
placenta fully or partially attached to the lower uterine segment
What is the difference between minor and major placenta praevia
minor - low lying but does not cover internal os
major - lies over the internal os
What are the risk factors for placenta praevia
previous C section high parity >40 multiple prgnancy prev placenta praevia endometritis prev curettage - miscarriage/termination
What are the features of placenta praevia
painless PV bleed - ranges from spotting to major haemorrhage
not tender on palpation
How is minor placenta praevia managed?
may be able to deilver vaginally
if <2cm distance from the os, c section recommended
How is major placenta praevia managed?
c section at 38 weeks
no penetrative sex
no vaginal or speculum examinations
admission from 34 weeks as such high risk of haemorrhage in vaginal birth
can stay at home if live nearby and have constant companion must come into hospital immediately if pain, contractions or bleeding
What is placenta accreta? What are the risk factors? and what problems does it cause?
placenta is morbidly attached ot uterine wall
risk factors: praevia, prev c section
increased risk of retained placenta and PPH
What is uterine rupture?
full thickness disruption of the uterine muscles and overlying serosa
What is the difference between incomplete and complete uterine rupture
incomplete - peritoneum overlying uterus still intact. uterine contents remain within uterus
complete = peritoneum is torn. uterine contents enter abdominal cavity!
What are the risk factors for uterine rupture
anything that makes the uterus weaker!
prev c section prev uterine urgery induction obstruction of labour multiple pregnancy multiparity
What are the features of uterine ruptire
PV bleed abdominal pain - sudden, severe, persists between contractions shoulder tip pain regression of presenting part palpable fetal parts in abdominal cavity shock fetal distress
What is the management of uterine rupture
A - AIRWAY
B - high flow o2
C two large bore cannulae, bloods up to 2L warmed crystalloid fluids until blood arrives cross matched blood - 4 units ?FFP, cryoprecpitate
Decide on delivery!
C section
repair or hysterectomy of uterus
What are the complications of uterine rupture
post operative infection amniotic embolus pituitary failure - Sheehan's syndrome ureter damage DIC
what questions are important to ask when taking a history in antepartum haemorrhage
how much blood? red/brown mucus? post coital? abdominal pain? fetal movements
RISK FACTORS
What should be examined in antepartum haemorrhage
signs of shock
abdo - tender, woody, contractions, fetal parts
speculum (if praevia ruled out) - dilation, rupture of membranes, clots
Describe the different categories of C section
1 Immediate threat to the life of the woman or fetus
2 Maternal or fetal compromise that is not immediately life-threatening
3 No maternal or fetal compromise but needs early delivery
4 Elective – delivery timed to suit woman or staff
Give some indications for a c section
Breech presentation (at term)
Other malpresentations – e.g. unstable lie (a presentation that fluctuates from oblique, cephalic, transverse etc.), transverse lie or oblique lie.
Twin pregnancy – when the first twin is not a cephalic presentation.
Maternal medical conditions (e.g. cardiomyopathy) – where labour would be dangerous for the mother.
Fetal compromise – where it is thought the fetus would not cope with labour.
Transmissible disease (e.g. poorly controlled HIV).
Primary genital herpes (herpes simplex virus) in the third trimester – as there has been no time for the development and transmission of maternal antibodies to HSV to cross the placenta and protect the baby.
Placenta praevia
Maternal diabetes with a baby estimated to have a fetal weight >4.5 kg.
Previous major shoulder dystocia.
Previous 3rd/4th perineal tear where the patient is symptomatic
Maternal request – after a multidisciplinary approach including counselling by a specialist midwife.
When are elective c sections normally planned for?
after 39 weeks gestation
reduces risk of TTN - respiratory distress in newborn
What management needs to take place prior to a c section
FBC
G+S
H2-receptor antagonist (risk of Mendelson’s syndrome - aspiration of gastric contents into the lunG, leading to a chemical pneumonitis. This is because of pressure applied by the gravid uterus on the gastric contents)
Calculate VTE risk and prescribe Anti-thromboembolic stockings +/- LMWH as appropriate.
How is the woman prepared for a c section in the operating theatre
left lateral tilt of 15° – to reduce the risk of supine hypotension due to aortocaval compression.
indwelling Foley’s catheter is inserted when the anaesthetic is ready - to drain the bladder and to reduce the risk of bladder injury during the procedure.
Give the steps in the c section procedure
Skin incision - Pfannenstiel or Joel-Cohen
Sharp or blunt dissection into the abdomen is made through several layers:
The skin,
Camper’s fascia (superficial fatty layer of subcutaneous tissue)
Scarpa’s fascia, (deep membranous layer of subcutaneous tissue)
Rectus sheath, (anterior and posterior leaves laterally, that merge medially)
Rectus muscle,
Abdominal peritoneum (parietal)
to reveal the gravid uterus.
The visceral peritoneum covering the lower segment of the uterus is then incised and pushed down to reflect the bladder, which is retracted by the Doyen retractor.
Uterine incision is made on the lower uterine segment beneath the line of peritoneal reflection. This is a transverse curvilinear incision which is digitally extended.
The baby is then delivered cephalic/breech with fundal pressure from the assistant.
Oxytocin 5iu is given intravenously by the anaesthetist to aid delivery of the placenta by controlled cord traction by the surgeon.
The uterine cavity is ensured empty, then closed with two layers. The rectus sheath is then closed and then the skin (either with continuous/interrupted sutures or staples).
Give the layers that need to be cut through in order to reach the uterus
The skin,
Camper’s fascia (superficial fatty layer of subcutaneous tissue)
Scarpa’s fascia, (deep membranous layer of subcutaneous tissue)
Rectus sheath, (anterior and posterior leaves laterally, that merge medially)
Rectus muscle,
Abdominal peritoneum (parietal)
visceral peritoneum
What does a primary c section reduce the risk of (when compared to VB)
perineal trauma and pain, urinary and anal incontinence, uterovaginal prolapse, late stillbirth early neonatal infection
What are the immediate risks of c section
Major Postpartum haemorrhage Wound haematoma (increased in patient with large BMI/diabetes/immunosupressed) Intra-abdominal haemorrhage Bladder/bowel trauma (more common in patients who have had previous abdominal surgery)
Neonatal:
transient tachypnoea of the newborn
fetal lacerations (1-2% risk, higher with previous membrane rupture)
What are the intermediate risks of c section
Infection:
urinary tract infection
endometritis
respiratory (higher risk if general aneasthetic used)
Venous thromboembolism
What are the late risks of c section
Urinary tract trauma (fistula)
Subfertility (there is a delay in conceiving compared to women who have had vaginal deliveries)
Regret and other negative psychological sequelae
Rupture/dehiscence of scar at next labour (VBAC)
Placenta praevia/accrete
Caesarean scar ectopic pregnancy
What are the benefits and risks of VBAC compared to planned elective repeat c section
benefits:
shorter recovery
less risk maternal dearh
less risk resp problems in neonate
risks: uterine rupture, anal sphinchter injury HIE to neonate still birth
What do guidelines say needs to be done in VBAC to ensure a safe delivery
deliver in a hospital setting with facilities for emergency caesarean and advanced neonatal resuscitation.
There should be continuous CTG monitoring.
Avoid induction where possible and be cautious with augmentation (increased risk of uterine scar rupture)
Any decisions about both induction and augmentation require input from a senior obstetrician.
After 39 weeks an elective repeat caesarean is recommended delivery method.
What methods of induction are appropriate in VBAC
using mechanical techniques (e.g. amniotomy)
better than induction with prostaglandins.
What are the absolute contraindications to a VBAC
classical caesarean scar,
previous uterine rupture
and any other contraindications for vaginal birth that apply to the clinical scenario (for example placenta praevia).
What are relative contraindications to a VBAC
complex uterine scars
>2 prior lower segment Caesarean sections.
How many minutes should a category 1 c section be delivered within
the baby should be born within 30 minutes
How many minutes should a category 2 c section be delivered within
not a universally accepted time,
usual audit standards are between 60-75 minutes.
What can initiate labour?
show - cervical plug falls out
ROM
Describe the first stage of labour.
talk about the contractions, dilation and effacement
early/latent: irregular contractions 0-3cm dilation, 30% effacement every 5-30mins last for 30 seconds THEN regular contractions 3-6cm dilation, 80% effacement every 3-5mins last for >=1 minute
active: intense contractions 6-10 cm dilation, 100% effacement every 0.5-2mins last for 60-90 seconds ROM if not already
Describe the second stage of labour
cardinal movements!
descent engagement flexion internal rotation extension delivery of head restitution - external rotation expulsion - ant shoulder, posterior shoulder, rest of body
What is the fetal station
the relationship of the presenting part to the ischial spines. At 0 (the level of the ischial spines), the fetus is engaged.
What is the lie of the fetus
the relationship between the long axis of the fetus and the mother
Describe the difference between longitudinal, transverse and oblique lie
longitudinal - head or bottom down. vertical
transverse - horizontal
oblique - at an angle. neither horizontal or vertical
What is the presentation of a fetus
fetal part that first enters the maternal pelvis.
What is the most common fetal presentation
Cephalic vertex
What different kinds of fetal presentation are there
cephalic breech shoulder face brow
What is the position of a fetus
position of the fetal head as it exits the birth canal.
What are the types of fetal position. Which is best?
occipito-anterior position (the fetal occiput facing anteriorly, anterior fontanelle felt posteriorly) – this is ideal for birth
occipito-posterio
occipito-transverse.
How is fetal position assessed?
vaginal examination during labour
What are the risk factors for fetal malpresentation
prematurity multiple pregnancy uterine abnormalities fetal abnormalities placenta praevia primparity
What can lead to a occipito-posterior position of the fetus
flat sacrum
poorly flexed head
weak uterine contractions
What investigations should be done in suspected malpresentation
USS to confirm and identify uterine or fetal abnormalities
What are the potential management options in fetal malpresentation
ECV
c section
vaginal delivery - high risk
How successful is ECV
50% in primips
60% in multips
What are the complications of ECV
fetal distress
RPOM
antepartum haemorrhage
placental abruption
Give the contraindications for ECV
recent APH
ruptured membranes
uterine abnormalities
prev C section
How is a shoulder presentation managed at delivery
C section
How is a brow presentation managed at delivery
C section
How is a face presentation managed at delivery
if chin anterior, vaginal delivery is possible. but it will be long and c section may still be required
if chin posterior, c section
How is a transverse presentation managed at delivery
C section
How is a occipitoposterior position managed at delivery
it will be a long labour - give adequate pain relief
may require forceps or c section
How is a occipitotransvese presentation managed at delivery
vaginal delivery - needs rotation with Kielland’s manoeuvre or ventouse
can end up with c section
What is breech?
fetus presents ‘bottom-down’ in the uterus.
Describe the different kinds of breech presentation
frank - hips flexed, knees extended. most common
complete - fully flexed legs
incomplete/footling - one or both thighs extended
What are the risk factors for breech presentation
Maternal: Multiparity - lax uterus Uterine malformations (e.g. septate uterus) Fibroids Placenta praevia smoking diabetes prev breech
Fetal: Prematurity Macrosomia Polyhydramnios (raised amniotic fluid index) Twin pregnancy (or higher order) Abnormality (e.g. anencephaly)
Give some differentials for breech presentation
oblique
transverse
unstable lie - more common in poyhydraminos, multiparity
When is breech presentation considered a problem?
beyond 32 weeks
before then, fetus will commonly turn
How can breech presentation be identified?
Subcostal tenderness.
Ballottable head in the fundal area.
Softer irregular mass in the pelvis.
Fetal heartbeat loudest above the umbilicus.
On VE in labour, the sacrum, anus or foot can be palpated through the fornix.
When is ECV given in breech
primip - after 36 weeks
multip - after 37 weeks
Why is a C section recommened for breech compared to a vaginal breech delivery
reduced risk of perinatal death and early neonatal morbidity
When is vaginal breech delivery considered unfavourable
placenta praevia contracted pelvis footling breech <2000g or >3800g hyperextended fetal neck in labour no suitably trained clinician available prev c section
What are the potential complications of a breech presentation
cord prolapse!!! fetal head entrapment PROM birth asphyxia - due to delay in delivery intracranial haemorrhage cervical spine injuries DDH
What is the difference between monozygotic and dizygotic twins
mono - one ovum fertilized, splits
di - two ovum fertilized. each have their own amnion, chorion and placenta
What is the result if an embryo splits at 3 days to form twins
two placenta, two chorions, two amnions
What is the result if an embryo splits at 4-7 days to form twins
one placenta. one chorion, two amnions
What is the result if an embryo splits at 8-12 days to form twins
one placenta. one chorion, one amnion
What is the result if an embryo splits at 13d days to form twins
conjoined twins
What is the risk of having monochorionic twins
twin to twin transfusion syndrome
reduced blood supply and therefore growth restriction for one twin
How is TTTS managed
laser surgeryof intertwin vascular placental anastamoses if <26w
septostomy
amnioreduction
selective feticide
What are the risk factors for multiple pragnancy
prev multiple pregnancy maternal FH of multiple pregnancy increasing maternal age race - high in west african assisted conception
How are multiple pregnancies discovered
on USS! hyperemesis exaggerated pregnancy-related symptoms. uterus palpated abdominally earlier than 12 weeks of gestation. large-for-dates uterine size, higher than expected weight gain, more than two fetal poles on palpation two or more fetal heart rates heard on auscultation.
What antenatal management needs to be considered for multiple pregnancies
obstetrician!!
USS - at least fortnightly. check fetal weights for any sing of IUGR
monitor FBC - increased risk of anaemia
BP - increased risk of pre-eclampsia. give aspirin if high
How is the delivery of multiple pregnancies managed
suggest delivery at:
35w if triplets
36 weeks if monochorionic twins
37w if dichorionic twins
G+S on admission as complications more likely
trial vaginal delivery if first twin cephalic
c section if not
Who needs referral to a tertiary centre specialist unit for antenatal care in a multiple pregnancy
Monochorionic monoamniotic twin or triplet pregnancies.
Monochorionic diamniotic or Dichorionic diamniotic triplet pregnancies.
Asymmetrical fetal growth.
Fetal anomaly.
Death of one fetus.
Twin-twin transfusion syndrome (TTTS).
What are the risks to the mother in multiple pregnancy
miscarriage anaemia pre-eclampsia APH PPH hyperemesis polyhydraminos death - 2.5 increased risk
What are the risks to the fetus in multiple pregnancy
stillbirth prem neonatal mortality and morbidity TTTS umbilicial cord entanglement IUGR congenital abnormalities
Which women are at increased risk of NTDs and therfore should take high dose folic acid
Either partner has an NTD, they have had a previous pregnancy affected by an NTD, or they have a family history of an NTD.
The woman is taking anti–epileptic medication.
coeliac disease or other malabsorption state,
diabetes mellitus,
sickle cell anaemia,
thalassaemia.
BMI >30
What are the key symptoms of obstetric cholestasis
in the third trimester
Intense pruritus ± excoriation, affecting any part of the body but particularly the palms and soles. Worse at night.
Pale stool, dark urine, jaundice.
Malaise and fatigue.
What are the risk factors for obstetric cholestasis
Past history of obstetric cholestasis. Family history of obstetric cholestasis - eg, mother. Multiple pregnancy. Presence of gallstones. Hepatitis C.
What blood results are found in obstetric cholestasis
abnormal LFTs
particularly AST and ALT elevation
Name some other causes of abnormal LFTs in pregnancy
gallstones, hepatitis, Epstein-Barr virus, cytomegalovirus, medications, autoimmune process hyperemesis pre-eclampsia HELLP fatty liver of pregnancy
What investigations need to be done if there are abnormal LFTs in pregnancy
urine dip, BP
hepatitis antibodies, virology screen, anti-smooth muscle and antimitochondrial antibodies
liver USS
How is obstetric cholestasis managed?
monitor LFTs weekly
ursodeoxycholic acid - facilitates bile flow through the liver
induction of labour at 37 weeks
What are the risks of obstetric cholestasis
Stillbirth Premature delivery Fetal distress. Meconium aspiration. Vitamin K deficiency in mother and fetus
How is cord prolapse managed
Displace the presenting part by putting a hand in the vagina; push it back up (towards mother’s head) during contractions.
Knee-to-chest position so that her bottom is higher than her head.
Infuse 500mL saline into bladder via an IVI giving set taped to a catheter
Tocolysis (terbutaline 0.25mg sc) reduces contractions and helps bradycardia
Delivery!!!
What is shoulder dystocia
a delivery requiring additional obstetric manoeuvres to release the shoulders after gentle downward traction has failed
What are the risk factors for shoulder dystocia
Large/postmature fetus (but most babies >4800g do not develop it and 48% that do weigh <4000g), maternal BMI >30kg/m2
• Induced or oxytocin augmented labours
• Prolonged 1st or 2nd stage or secondary arrest
• Assisted vaginal delivery
• Previous shoulder dystocia (1–16%). Most occur in women with no risk factors.
• Diabetes mellitus.
How is shoulder dystocia managed
- Help: extra midwives, labour ward coordinator, senior obstetrician, neonatologist, anaesthetist and a scribe for timing of manoeuvres.
- Episiotomy: to give space for internal manoeuvres.
- Legs: place in McRoberts (hyperflexed lithotomy) position. It is successful in 90%. Abduct, rotate outwards, and flex maternal femora so each thigh touches the abdomen (1 assistant to hold each leg). This straightens the sacrum relative to the lumbar spine and rotates the symphysis superiorly helping the impacted shoulder to enter the pelvis without manipulating the fetus.
- Suprapubic pressure with flat of hand laterally in the direction baby is facing, and towards mother’s sacrum, continuously or with a rocking motion. Apply steady traction to the fetal head. This aims to displace the anterior shoulder allowing it to enter the pelvis.
- Enter the pelvis for internal manoeuvres; these aim to rotate the fetal shoulders to the oblique diameter. If this fails, rotation by 180° so posterior shoulder now lies anteriorly may work, as may delivery of the posterior arm.
- Roll the mother on to all fours if these fail.
- Check the baby for damage, eg Erb’s palsy or fractured clavicle.
- Beware PPH or 3rd/4th degree vaginal tears in the mother.
