Abnormal labour Flashcards
What is PPROM (as opposed to PROM) and how is it diagnosed?
-Premature pre-labour rupture of membranes ie <37 weeks
DIAGNOSIS
-Pooling of amniotic fluid seen on sterile speculum
–NB do not perform vaginal examination due to infection risk
-AMNISURE= placental alpha-microglobulin-1 test
What is the probability of spontaneous labour in PPROM vs SROM at term?
PPROM = 80% within 7 days
SROM at term = 90% within 48h
How should PPROM be managed?
Aim is to bide time to delay delivery
-Prophylactic steroids to help with foetal lung maturity (betamethasone 12mg IM, 2 doses 24h apart)
-Antibiotics (erythromycin 250mg QDS for 10 days)
-Intrapartum antibiotic prophylaxis (IAP) should be given during delivery (IM 1.5g Ben-pen)
-Induce labour:
–around 34w if signs of infection
–around 37w if no signs
unless maternal / foetal distress implied
What are the complications of a PPROM before foetal viability?
Absence of amniotic fluid causes the following problems:
-Pulmonary hypoplasie due to reduced ability to ‘practice’ breathing
-Infection risk
-Limb problems due to inability to move
-GI problems - normally foetus ingests fluid and excretes it to keep the oesophagus patent and kidneys functioning
How is breech presentation defined?
-Foetal position in utero oriented so the buttocks are delivered first
-Can be:
–Frank / extended (65%)
–Complete / flexed (10%)
–Incomplete / footling (25%) (pre-term + highest risk)
How should a breech presentation be managed?
1.External cephalic version (ECV)
2. C-section (reduced morbidity and mortality for breeched babies compared to VD)
3. Planned vaginal delivery
(Moxibustion = acupuncture alternative)
What risk factors are there for breech presentation?
-Uterine malformations
-Fibroids
-Placenta praevia
-Polyhydramnios / oligohydramnios
-Foetal abnormality
-Prematurity
What risks are associated with breech presentation?
-Cord prolapse (position creates a less effective ‘plug’ on cervix)
-Difficulty delivering head
-Foetal hypoxia
-Increased foetal morbidity and mortality
What does ECV involve?
-Applying gentle pressure to the abdomen to turn the foetus
-Done at 36-37 weeks (if <36 weeks most will turn spontaneously)
-Tocolytics given to relax uterine muscles, allowing movement
-CTG monitoring pre- and post-procedure
-Success rate = 50%, 5% chance of moving again once successfully rotated
What risks are associated with ECV?
-Foetal distress
-Cord entanglement
-Transient foetal bradycardia
-Pain
-Foeto-maternal haemorrhage (give Anti-D in Rh- patients)
-Placental abruption
What are some contra-indications for ECV in breech presentations?
ABSOLUTE
-Placenta praevia
-Uterine malformations
-Ruptured membranes
-Abnormal CTG
-Multiple pregnancies
RELATIVE
-Previous CS
-Active labour
-Pre-eclampsia
-Oligohydramnios
-Foetal abnormalities
-Hyperextension of foetal head
-Maternal cardiac disease
What is the main factor in determining pregnancy outcome in twins / higher order pregnancies?
-Chorionicity
= whether twins share a placenta or not
What are the 4 types of chorionicity / amnioticity and what do they mean?
Dichorionic / Diamniotic = 2 placentas + 2 sacs (DCDA)
Monochorionic / Diamniotic = 1 placenta + 2 sacs (MCDA)
Monochorionic / Monoamniotic = 1 placenta + 1 sac (MCMA)
Conjoined twins
When are the different cleavage times for pregnancies of different chorionicities?
DCDA = days 1-3
MCDA = days 4-8
MCMA = days 8-13
Conjoined = days 13-15
NB all dizygotic twins are DCDA, monozygotic twins can be any
What do T and lamda signs denote on USS of twin pregnancies?
-Lamda sign = DCDA
-T = MCDA
What maternal complications does a multiple pregnancy carry?
-Hyperemesis gravidarum
-Anaemia
-GDM + G-HTN
-Placenta praevia
-Miscarriage
-Preterm labour and delivery
-Pre-eclampsia
-Antepartum haemorrhage
-Postpartum haemorrhage
-Postnatal depression
What foetal complications does a multiple pregnancy carry?
-Polyhydramnios
-Prematurity
-Malpresentation
-Cord prolapse
-Placental abruption
-Chromosomal / congenital abnormalities (2-3 times higher for monozygotic twins)
-IUGR
-Intrauterine death
What is twin-twin transfusion syndrome?
-Occurs in monochorionic pregnancies
-One foetus dominates over the other, creating an imbalance in placental blood flow to each foetus
-Donor = smaller, fails to thrive, higher risk of intrauterine death
-Recipient = fluid overload, heart failure, more risks postnatally, polyhydramnios, cardiac hypertrophy
-Trocar procedure divides blood vessels to manage this
What additional antenatal care is needed for multiple pregnancies?
-Higher dose folic acid (5mg)
-Aspirin 75mg
-Detailed anatomy and cardiac scans
-Regular growth scans (4-weekly if DCDA, 2-weekly if MC)
-Regular BP and urine checks (pre-eclampsia)
-OGTT at 28 weeks
When and how should twins be delivered?
-DCDA = 37-38 weeks
-MCDA = 36 weeks
-MCMA = 32-34 weeks by CS
-If presenting twin is cephalic –> vaginal delivery
-If presenting twin is breech / transverse –> CS
How is delayed labour diagnosed (1st stage)?
Primigravida = dilatation of <2cm in 4h
Multigravida = dilatation of <2cm in 4h or slowing of progress
What are the 3Ps that influence progress in labour?
POWER - uterine contraction
PASSENGER - foetal position, foetal size
PASSAGE - parity, pelvis
How is slow progress managed in the 1st stage of labour?
-ARM
-Syntocinon infusion
-C-section if all else fails
What does the partogram show?
A pictorial record of labour, showing:
-Cervical dilatation and descent of head
-Frequency of contractions
-Foetal HR
-Colour of liquor
-Maternal obs
-Any drugs / fluids given
When is instrumental delivery indicated?
-Slow progress in 2nd stage of labour
-Maternal exhaustion
-To avoid raising ICP
-To avoid raising BP
-Presumed foetal compromise
When can instrumental delivery be considered?
-Once fully dilated
-Membranes must be ruptured
-Cephalic presentation
-Engaged part must not be abdominally palpable
What are the different methods of instruments used in assisted vaginal delivery?
-Vacuum extraction / Ventouse
–Baby must be in correct position, takes 3-4 contractions, difficult to get a good seal
–Risk of cephalohaematoma
-Traction forceps
–Baby must be in correct position, takes 1-2 contractions
–Risk of facial nerve palsy, facial paralysis, bruising
-Rotational forceps
–Risks as above
What maternal risks are associated with instrumental delivery?
-Postpartum haemorrhage
-Pain
-Perineal trauma / need for episiotomy
–Anal sphincter tears
-Incontinence
-Psychological distress
-Obturator or femoral nerve injury
What is shoulder dystocia and what risks are associated with it?
-Occurs when anterior shoulder becomes stuck behind the pubic bone during vaginal delivery (once head is out)
RISKS
-Postpartum haemorrhage
-Perineal tears
Foetus:
-Hypoxia
-Brachial plexus injury
-Intracranial haemorrhage
-Cervical spine injury
-Death
What risk factors make shoulder dystocia more likely?
-Hx of shoulder dystocia
-Lack of progress in 1st/2nd stage of labour
-Foetal macrosomia
-High maternal BMI
-Diabetes
-Prolonged labour
What management options are there to correct shoulder dystocia?
PALE SISTER (order of interventions)
Prepare
Assistance
Legs (McRoberts)
Episiotomy
Suprapubic pressure
Internal Rotation
Screw (reverse Wood’s)
Try recovering posterior arm first
Extreme measures eg break pubic bone, CS
Repair + record
-McRobert’s manoeuvre = flex and externally rotate hips to stretch symphysis and open pelvic outlet
What are the 2 types of C-section?
-Lower segment (99%)
-Classic (longitudinal incision in upper segment of uterus)
What indications are there for a CS?
-Cephalopelvic disproportion (CPD)
-Placenta praevia grades 3-4
-Pre-eclampsia
-Post-maturity
-IUGR
-Foetal distress in labour / prolapsed cord
-Failure to progress in labour
-Malpresentations
-Placental abruption (but if IUD then deliver vaginally)
-Vaginal infection eg active herpes
-Cervical cancer
What risks does CS pose to the mother?
SERIOUS
-Emergency hysterectomy
-Need for further surgery / ICU admission
-VTE
-Bladder / ureteric injury
-Death (v rare)
FREQUENT
-Persistent wound / abdominal discomfort
-Increased risk of future CSs when VBAC admitted
-Haemorrhage
-Infection
What risks does CS pose for future pregnancies?
-Increased risk of uterine rupture
-Increased risk of antepartum stillbirth
-Increased risk of placenta praevia and accreta
What is a transverse lie?
-Back of foetus is across the opening of the cervix
How long do you have before hypoxic injury occurs in shoulder dystocia?
-5 mins
