Antepartum Care Flashcards
Describe the blood supply within the placenta
Maternal artery and maternal vein are established by 14 weeks
Maternal artery brings oxygenated blood into the placenta and pools in the intervillous space
Umbilical vein then takes oxygenated blood from the intervillous space to the foetus
2x Umbilical arteries take deoxygenated blood away from the foetus
How do molecules get from the maternal blood supply to the foetal blood supply?
There is no direct mixing but both blood supplies come into close contact across the placental membrane (v thin)
Allows diffusion!
What are the 5 functions of the placenta?
RENIE
Respiratory
Excretion of waste products
Nutrition (glucose, Fe, Folate)
Immunity - IgG can pass but IgM is too big
Endocrine - HcG then progesterone after 5 weeks to maintain the endometrium and Oestrogen to soften ligaments and muscles etc
Describe normal placentation
Ideal place to implant is the posterosuperior 2/3 of the uterus
Decidua basalis separates myometrium from the placenta
Fibrin layer separates endometrium from placenta
What is the function of the fibrin layer during placentation? What is the clinical significance of this?
Prevents implantation becoming too deep
Allows clean cleavage during the 3rd stage of labour
Disruption can lead to: morbidly adherent placenta +/- retained placenta PPH/SPH Placental abruption Vasa/placenta praevia
What are the 3 types of morbidly adherent placenta?
Placenta Accreta
Placenta Increta
Placenta Percreta
Increases in depth as you go down the list and increase in maternal morbidity
Describe the 3 types of MAP
Accreta = placental villi are attached to the myometrium
Increta = placental villi have invaded the myometrium
Percreta = placental villi pass through the myometrium into the serosa and maybe into other structures e.g. bladder
How does a morbidly adherent placenta normally present?
Painless, bright red PV bleeding
Hopefully diagnosed antenatally on USS
What are the modifiable risk factors for MAP?
Essentially anything that scars the uterus e.g.
Repeated caesareans
Repeated TOP
IVF
Endometrial ablation
When should MAP/retained placenta be suspected (if not already diagnosed)?
Suspect if the placenta HAS NOT been delivered within:
- 30 mins of baby in an actively managed labour
- 1 hour of baby in a physiological 3rd stage
What is the immediate management of MAP/retained placenta?
IV access, FBC, Cross match (should already have)
Physiological labour becomes active = oxytocin into umbilical vein +/- cord traction
Manage haemorrhage as and when
What is the definitive management of MAP/retained placenta?
Not removed within 30 mins =
theatre for Manual removal (scrape it with hand whilst putting pressure on uterus with other hand)
+ antibiotic prophylaxis
What are the maternal complications of MAP/retained placenta?
Some general surgical - bleeding/ VTE/ Injury to surrounding structures/ infection
Specific - emergency hysterectomy
What are the neonatal complications of MAP/retained placenta?
Stillbirth/death
Small for gestational age
Define antepartum haemorrhage
Bleeding from the genital tract during pregnancy
At or after 24 weeks gestation
Before the onset of labour
What are the dangerous placental causes of antepartum haemorrhage?
Placenta praevia
Placental abruption
Vasa praevia
What are the cervical causes of antepartum haemorrhage?
polyps
erosions
carcinoma
cervicitis
What are the non-dangerous placental causes of antepartum haemorrhage?
Circumvallate placenta (chorionic plate is too small so doubles back on foetal side)
Placental sinuses
What is placental abruption?
Premature separation of a normally located placenta from the uterine wall before delivery of the foetus
What is the pathophysiology of placental abruption thought to be?
Rupture of maternal vessels in basal layer of endometrium
Blood accumulates = splitting of placental attachment from basal layer
Foetal compromise happens quickly as placenta can’t do its job
What are the 2 types of placental abruption?
Concealed
Revealed
Describe a concealed placental abruption
Bleeding stays in uterus, usually retroplacentally
No PV bleed but can still lead to systemic shock!
Describe a revealed placental abruption
Bleeding can come down the side of the separation and out of cervix
Results in a PV bleed
What are the non-modifiable risk factors for placental abruption?
Underlying thrombophilia
Multiple pregnancy
Increased maternal age
Previous Hx Placental abruption
What are the modifiable risk factors for placental abruption? (4)
Past hx of PA
PWID/cocaine/smoking
Trauma
Pre-eclampsia/HTN
How would a placental abruption normally present?
PAINFUL, PV bleeding
(pain is sudden onset, constant and severe)
Woody hard abdomen
Later signs = maternal shock and foetal distress
Why does a woody hard abdomen occur in a placental abruption?
Bleeding causes irritation to the uterus
Irritation = contractions
Can lead to premature labour
What are the bedside tests to do for a placental abruption and why?
Do baseline obs to watch for signs of shock
Which blood tests should be done to manage a placental abruption? (6)
FBC - Hb
Cross match - in case a blood transfusion is needed
U&E - monitor kidney function in case haemorrhage = AKI. AND to check pre-eclampsia/HELLP
LFTs - exclude HELLP
Coagulation
Kleihauer - check rhesus status
What imaging can be done to manage a placental abruption?
USS to differentiate from placenta praevia
Foetal monitoring via CTG
What is the overall management for a placental abruption?
Admission and A→E
Get expert help
Conservative
Severe bleeding = put legs up
Catheterise
Medical
Severe = Fresh ABO Rh compatible or O Rh -ve blood
Surgical
Deliver if signs of foetal distress
IOL if at term
Define placenta praevia
When either the whole of the placenta or just a part is inserted into the lower segment of the uterus
Needs to still be low at 28 weeks as often implants lower but moves higher as the uterus grows
What is minor vs major placenta praevia?
Minor = placenta is in lower segment but does not cover the internal os
Major = placenta covers the internal os. Bad because a normal labour cannot occur
How does placenta praevia normally present?
PAINLESS, PV bleeding
Warning bleeds throughout pregnancy
What are the non-modifiable risk factors for placenta praevia?
Multiple pregnancy
Maternal age >40
What are the modifiable risk factors for placenta praevia?
Past hx of PP
Scarring of uterus e.g. IVF, TOP, previous caesarean
Fibroids
Are there any investigations to diagnose a placenta praevia?
YES
Should be diagnosed on USS antenatally (trans-vaginal) at 20 weeks
Acutely and if major bleeding is suspected, the same Ix should be done as for placental abruption
When should USS be repeated in a patient with diagnosed placenta praevia?
Minor - Repeat USS at 36 weeks
Major - Repeat USS at 32 and make a plan for delivery if still low
When should an elective caesarean be offered in a patient with known praevia?
38 weeks if major
Define vasa praevia
Foetal vessels run in membranes below the presenting foetal part
Unsupported by placental tissue or umbilical
Where do the vessels arise from in vasa praevia?
A velamentous umbilical cord
OR
An accessory placental lobe
What is a velamentous umbilical cord?
Cord inserts into foetal membranes rather than the centre of the placenta
How does vasa praevia normally present?
A triad!
Foetal bradycardia
PAINLESS pv bleeding
Membrane rupture
What are the non-modifiable risk factors for vasa praevia?
Accessory placental lobe
Velamentous umbilical cord
Multiple pregnancy
What are the modifiable risk factors for vasa praevia?
IVF pregnancy
What are the investigations for vasa praevia?
Investigate haemorrhage as per antepartum haemorrhage
Diagnose by TAS and TVS with doppler antenatally
How should a known vasa praevia be managed?
Elective c-section at 34-36 weeks if confirmed in 3rd trimester
+ ?prophylactic hospitalisation based on PROM risk factors
How should PROM or a spontaneous ROM be managed in a patient with vasa praevia?
Emergency c-section
Which 2 medical conditions should you not breastfeed if you have?
Galactosaemia
HIV
Give 6 [classes of] drugs that should be avoided in pregnancy
Trimethoprim NSAIDs ACEI Warfarin Anticonvulsants e.g. Valproate Vitamin A e.g. Retinoids
When would Erb’s palsy occur and how does it present?
Damage to the upper brachial plexus most commonly from shoulder dystocia
adduction + internal rotation of arm + pronation of forearm (waiter’s tip)
Which screening tool is for postnatal depression?
Edinburgh scale
Define an amniotic fluid embolism
when fetal cells/ amniotic fluid enters the mothers bloodstream and stimulates a reaction which results in cyanosis, hypotension bronchospasm etc
Usually occurs during labour
When is the dating scan?
10-13+6 weeks
When is the Down’s syndrome + nuchal scan?
11-13+6 weeks
When is the foetal anomaly scan?
18 - 20+6 weeks
When should rhesus negative women be given anti-D?
28 weeks
34 weeks
Within first 72h of birth
Give 4 non-pharmacological methods of analgesia during labour
Education - about labour, breathing exercises
TENS - not in established labour
Water birth - not if high risk. Have to keep water below 37.5
A consistent and supportive birth partner!
How does inhaled nitrous oxide (entonox) work?
Inhibit NMDAr = Increases GABA activity = mild analgesia and anxiolytic but mainly dissociative about pain less
What are the benefits and disadvantages of using entonox?
+ves = cheap, fast, reversible. Doesn’t affect baby. Good for 1st stage as don’t push so protects perineum
-ves = CI if severe asthma or pneumothorax, ADRs = N&V, drowsy
What are the benefits and disadvantages of giving systemic opioids e.g. Pethidine, diamorphine during labour?
Not many benefits
-ves = limited analgesic effect, V emetic, significant Session e.g. mother = drowsy, N&V, pethidine is associated with fits, baby = short term RDS, drowsy)
What is epidural anaesthesia?
A catheter is inserted into the epidural space which allows continuous anaesthesia/can be topped up
Does not cross ligament flavour
Analgesic effect is at nerve roots leaving dura rather than on the whole spinal cord
What are the benefits and disadvantages of epidural anaesthesia?
+ves = can give regular top ups, good analgesia, can help Lower BP in pre-eclampsia, can do anywhere in spine (theoretically)
-ves = takes 30-45 mins to work, increases risk of operative delivery (so tears and PPH too), post puncture headache, hypotension
What is spinal anaesthesia?
A single injection of anaesthetic into the subarachnoid space so injected directly into the CSF and acts directly on the spinal cord
Do between L3-L5 to avoid conus medullar is (L1-L2) = avoid spinal cord injury
Get a complete motor and sensory block below the level of injection
What are the benefits and disadvantages of giving a spinal anaesthetic?
+ves - quick onset, for shorter procedures
-ves = can move up the SA space to brainstem = LOC, respiratory depression. Might wear off in procedure is prolonged, more profound hypotension
Are NSAIDs ok to use during pregnancy and the puerperium?
Not really - avoid before and after 30 weeks
BUT
ok to use if breastfeeding
Define a first degree tear
Superficial and do not involve the perineal muscle
Only requires suturing if the edges are well apposed to aid healing
Define a second degree tear
Perineal muscles are involved
repair to episiotomy level
Define a third degree tear
Damage involves the anal sphincter (vajanus)
a = circular fibres of external anal sphincter = >50% torn b = external anal sphincter thickness = >50% torn c = ex and int anal sphincters are >50% torn
Define a fourth degree tear
Anal/rectal mucosa is also involved
What is the aftercare of a fourth degree tear?
Abx prophylaxis (same with 3rd degree)
High fibre diet + lactulose for 10 days
Pelvic floor physio
Why would an episiotomy be carried out?
Enlarge the outlet e.g. baby coming too quick, operative delivery
prevention of 3rd degree tear
Which tissues are cut in an episiotomy?
vag epithelium + perineal skin
bulbocavernous muscle
superficial + deep transverse perineal muscles
? anal sphincters and elevator ani
What are the complications of an episiotomy and how can this be managed?
Pain - ice packs, salt packs, rectal diclofenac
Bleeding +/- haematoma
Infection
Damage to surrounding structures
What is lochia?
All the shit that comes out after having a baby
endometrial slough, red cells, white cells
1-3 days = red
then yellow
then white @ 10 days
How would endometritis present?
Maternal pyrexia
Offensive lochia
Lower abdominal pain
Pain on bimanual
How is endometritis managed?
IV abx
What is lactational amenorrhoea?
No periods whilst breastfeeding
Disruption of frequency and amplitude of gonadotrophin surges = no ovulation
Under which circumstances can lactational amenorrhoea be an effective method of contraception?
Fully breastfeeding day and night
<6 months postpartum
amenorrhoeic
= 98% effective
When is the average 1st menstruation after having a baby if mother is breastfeeding?
28.4 weeks
When can the POP be started after childbirth?
Any time really
If started after 21 days then need additional methods for 2 days
When can the COCP be started after childbirth?
At 3 weeks IF NOT BREASTFEEDING
DONT USE IF BREASTFEEDING UNTIL AFTER 6 MONTHS although can be used at 6 weeks if other methods aren’t acceptable
When can emergency contraception be started after childbirth?
Any time - don’t need the 21 day thing
When can the depot be given after childbirth?
After 6 weeks if breastfeeding
Can be given 5 days or straight away if bottle feeding (depending on type)
When can the implant be put in after childbirth?
6 weeks if breastfeeding
21-28 days if bottle feeding
When can the IUD be put in after childbirth?
Either within first 48hr postpartum OR 4 weeks post partum
To reduce risk of uterine perforation at insertion
What is the triad seen with an amniotic fluid embolism?
Coagulopathy
Hypoxia
Hypotension
Give 4 non-pharmacological methods of pain management during labour
- Education about labour and breathing exercises
- Transcutaneous Electrical Stimulation (not if established labour)
- Water birth - temp <37.5 and not if high risk/opiates given in past 2 hours
- Position - side or squatting as back can squash lumbosacral plexus
Actually, a supportive partner has the most evidence
Give 2 medical methods of pain management during labour
Inhaled nitrous oxide (inhibits NMDAR so increases GABA - anxiolytic and dissociative)
Systemic opioids - pethidine and diamorphine
What are the positives and negatives of entonox?
+ves
- fast, reversible, cheap
- doesn’t affect baby and good in first stage as protects perineum
- ves
- CI = severe asthma and pneumothorax
- ADR = n&v and drowsy
What are the limitations of using systemic opioids during labour?
- Not much analgesic effect and makes mam drowsy
- Crosses placenta so have to give 4 hours before birth so it is cleared but hard to know when this will be - RDS in neonate
- V emetic so have to give anti-emetic too
- Pethidine also associated with seizures
Give 2 regional anaesthesia management options for pain during labour
Epidural - catheter into epidural space which allows continuous anaesthesia and can be topped up. Has effects on nerve roots leaving dura
Spinal - Single injection into subarachnoid space so directly into CSF. This means has a direct effect on spinal cord
What is the anatomical difference between an epidural and a spinal anaesthetic
Spinal crosses ligamentum flavosum to get into the subarachnoid space
Spinal has to be done between L3-L5 to avoid the conus medullaris (L1-L2)
Spinal = complete motor and sensory block below level wherea epidural is just sensory?
What are the benefits and limitations of an epidural?
+ves
- Regular top ups
- Good anaglesia
- Can help reduce BP esp with pre-eclampsia
- ves
- 30-45 mins to work
- Increased risk of operative delivery (and tears and PPH)
- Post puncture headache
- Hypotension
What are the benefits and limitations of a spinal?
+ves
- Faster onset and offset so good for shorter procedures
- ves
- Can move up SA space to the brainstem = resp compression
- might wear off if procedure is prolonged
- More profound hypotension
What are the definitions of primary PPH and secondary PPH?
Bleeding after 24 weeks!
Primary = within 24 Hours of delivery Secondary = within 24hrs - 12 weeks post delivery
What is the definition of a minor and major PPH?
minor = 500-1000mls blood loss + no clinical shock Major = 1000+mls + clinical shock
Vaginal delivery!!
What are the 4 categories of causes of PPH?
TONE - uterine atony
TISSUES - retained products/MAP
TRAUMA - to genital tract
THROMBIN - coagulopathy (pre-eclampsia, abruption, anti-phospholipid, liver disease), Heparin use
What are the antenatal risk factors for PPH?
NM = >35, uterine abnormality, low lying placenta
M = High BMI, previous PPH, para 4+
What are the intrapartum risk factors for PPH?
Modifiable - IOL + oxytocin, prolonged stages, CS/VOD
What are 4 complications of PPH?
Direct blood loss (hypovolaemic, DIC)
FLuid overload when replaced/acute transfusion reaction
ARDS
Sheehans Syndrome - hypo perfusion to pituitary (amenorrhoea, Addisons, hypothyroid)
How does PPH lead to DIC?
depletion of: fibrinogen, platelets, coagulation factors
Endothelial injury = coagulation at site of injury = activates cascade = widespread organ injury
Easy bleeding at other sites
Paradoxical as have thrombosis and bleeding at same time
Which blood tests should be done in PPH?
Clotting - APTT and PT are both prolonged, D-Dimer is increased
Others for baseline
What is the A to E management of PPH?
Left lateral tilt
A B - high flow O2 C - 2x grey cannula, 1L NaCl over 15 mins. RhD-ve, O-ve blood, FFP, Cryoprecipitate, Cell salvage D E - Catheter
What is the medical management of uterine atony?
Pharmacological = tranexamic acid, Oxytocin (No HTN), Ergometrine
What is the non-pharmacological management of uterine atony?
Uterine massage/bimanual compression
Balloon
Brace Suture
Hysterectomy (if can’t stop bleeding)
What is the definition of shoulder dystocia?
Delivery requiring additional obstetric manoeuvres to release the shoulders after gentle downward traction has failed
Anterior shoulder becomes impacted against pubic symphysis due to failed internal rotation
What are the antenatal and intrapartum risk factors for shoulder dystocia?
Antenatal = macrosomia, previous Hx, BMI >30, post dates, DM
Intrapartum = IOL/oxytocin, prolonged 2nd stage, failure to progress, intstrumental deliver
What is the management of shoulder dystocia?
HELPER A
Help and extra midwives, senior obstetrician, neonatologist, anaesthetist
Episiotomy
Legs - McRoberts Manoeuvre
Pressure (suprapubic)
Enter pelvis for internal manoeuvres :( :(
Roll mother to all fours
Anticipate PPH
What are the maternal and foetal complications of shoulder dystocia?
Maternal = PPH, uterine rupture, 3rd-4th degree tear
Foetal = Death, hypoxia (+neuro injury), Erb’s Palsy (C5 and C6!)
WHAT IS Erb’s palsy?
Injury to C5 and C6 nerves
Can’t abduct or externally rotate
Define cord prolapse
Cord protrudes below the presenting part AFTER rupture of membranes
It is an emergency because it compresses the cord = foetal asphyxia
See cord + foetal bradycardia/decelerations according to contractions
What is the management of cord prolapse?
Tell everyone on labour ward
Keep cord in vag but don’t handle too much due to vasospasm
Fill bladder with 500ml saline = obstructs
Tocolytics
Deliver ASAP
What are the normal and abnormal findings on CTG? How do you confirm foetal distress?
Good variability between 5-10bpm = normal
Non-variable, non-reactive, decelerations = abnormal
Confirm by foetal scalp blood sampling for acid base status every hour
What are the causes of suspected foetal compromise?
Power - uterine hyper stimulation, maternal hypotension, maternal infection
Passenger - IUGR
Passage
What is the management of the foetal heart rate dipping below 100bpm?
3 mins = call for help
6 mins = theatre and delivery
What is the chance of having a VBAC?
70-75%
Lower threshold to have c-section if have previous scarring or foetal compromise
What are the risks of having a VBAC?
1 in 200 = scar rupture
2 in 1000 = foetal death during labour but this is the same as in first labour
Foetal death risk in having a planned caesarean = 1 in 1000
Risk of emergency c-section in which case risk of scar rupture is 5 in 1000
