Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RANZCOG 2024 - Antenatal > Multiple pregnancy > Flashcards

Multiple pregnancy Flashcards

1
Q

Discuss twin pregnancies
-Incidence in spontaneously conceived twins (3)
-Overall incidence of twins (1)
-Number of twin pregnancies due to fertility treatment (1)
-Rate of rise of multiple pregnancies (2)
-Reasons why multiple pregnancies are more common (2)

A
  1. Incidence in spontaneous pregnancy
    -1:90 for twins 1%
    -1:10 000 triplets 0.01%
    -1: 600 000 quads 0.001%
  2. Overall incidence of twins
    -1.3% in NZ
  3. Number of with pregnancies due to fertility treatment
    -14%
  4. Rise in multiple pregnancies
    -70% increase over last 30 years
    -Spontaneous twins account for a third of overall rise
  5. Reasons for multiple pregnancies
    -Older age of mothers
    -ART
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Discuss multiple pregnancies
-What does zygosity mean
-What does chronicity mean

A
  1. Zygosity: Number of fertilised eggs that pregnancy develops from
  2. Chronicity: Number of chorionic membranes / number of placenta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Discuss dizygotic twins
-Incidence (1)
-Development (1)
-USS findings (4)

A
  1. Incidence - 70%
  2. Development
    -Develop from two eggs and two sperm (non-identical)
  3. USS findings
    -Scan between 10-14 weeks
    -Lambda sign
    -2 separate placental masses
    -Thick septal edge
    -Different sexes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Discuss monozygotic twins
-Incidence of DCDA, MCDA, MCMA (3)
-Development of different types (4)
-USS findings (3)

A
  1. Incidence
    -DCDA - 30%
    -MCDA - 70%
    -MCMA - 1%
    -Conjoined
  2. Development
    DCDA - single egg and sperm - Splits day 1-3
    MCDA - single egg and sperm splits day 4-8
    MCMA - single egg and sperm Splits day 8-13
    Conjoined - single egg and sperm splits day 13-15
  3. USS findings
    -Single placental mass
    -Thin septum <1.8mm
    -A-A anastomoses
    -T sign
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Discuss maternal complications of multiple pregnancies (14)

A

-Miscarriage
-Hyperemesis
-Anaemia
-GDM 2 x risk
-Preterm birth - iatrogenic and spontaneous
-Hypertensive disease 4 x risk
-VTE
-APH - increased placental bed
-Polyhydramnios - TTTS
-Operative delivery
-PPH - larger placental bed, over distension
-PND
-Maternal mortality 2.5 x risk
-Obstetric cholestasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Discuss fetal complications of multiple pregnancies (8 groups)

A

Increased mortality. Increases with increased number
-5:1000 singleton, 12/1000 twins, 31/1000 triplets
-Increased with monochronicity esp. 20-30 weeks
Chromosomal abnormalities
-DC - 2 x overall risk each fetus same risk as singleton
-MC - same risk as singleton but both twins affected
Structural abnormalities
-DC same risk as singleton so 2 x risk
-MC 2-3 times risk due to uneven distribution of inner cell mass
Fetal growth restriction 2-3 x risk. More common in MC
PPROM
PTB - 60% of twins born before 37/40. 9% before 32/40
Long term disability - 4-8 x increased risk of CP
Infant feeding difficulties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the monochorionic specific fetal risks (4)

A

-Cord entanglement
-Selective IUGR
-TTTS
-TAPS
-TRAP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Discuss aneuploidy screening in multiple pregnancies
-Which screening tools can be used for twins
-Which screening tools can be used for triplets

A
  1. Twin pregnancy can use MSS1, MSS2, NIPT
  2. Triplets can use MSS1 only
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Discuss MSS1 in multiple pregnancies
-When should MSS1 be done
-Which multiple pregnancies is it validated for
-How are results given for DC and MZ
-What is the sensitivity and why is it impacted

A
  1. MSS1 do 11-13+6
  2. MSS1 can be used in all twin and triplet pregnancies
  3. Results
    DC - gives a chance score for each twin
    MC - gives an overall chance score for the pregnancy
    For MC twins use average of NT as it can differ
  4. Sensitivity
    -Same as for singleton pregnancies.
    -Sensitivity is reduced secondary to maternal serum biomarkers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Discuss NIPT for multiple pregnancies
-When should NIPT be done
-Which multiple pregnancies is it validated for
-Discuss sensitivity and specificity for MZ and DZ twins
-Discuss reasons for higher failure rate (4)

A
  1. When should NIPT be done - After 10 weeks
  2. Which multiple pregnancies is it validated for - twins only
  3. Sensitivity and specificity
    -99% for both for MZ twins
    -Slightly less sensitive in DZ twins
  4. Reasons for higher failure rates in twins
    -Failure rate in singletons 2% failure in twins 6%
    -Low fetal fraction
    -Maternal obesity
    -Suboptimal sample collection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Discuss prenatal diagnosis
-What form of prenatal diagnosis should be used for DC twins and why
-What form of prenatal diagnostic test should be used for MZ twins and why
-What are the considerations for prenatal diagnostic testing

A
  1. What form of prenatal diagnosis for DC twins
    -CVS (11+2 - 13+6)
    -Can do KCL selective reduction and this is done better at early gestations
  2. What form of prenatal diagnosis for MC twins
    -Amniocentesis (15+)
    -Can’t do KCL for selective reduction. Must do cord occlusion. Better done later
  3. Considerations
    -Puts whole pregnancy at risk even if only one twin affected
    -KCL risk of loss of remaining twin = 15%
    -Cord occlusion risk of loss of remaining twin 13%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Discuss the implications of death of one twin
-Impact in MCDA (5)
-Impact if DCDA (6)

A
  1. Impact to MCDA twins
    -Risk of death of remaining twin - 40%
    -PTB 70%
    -Abnormal antenatal cranial imaging - 30%
    -Abnormal postnatal cranial imaging - 40%
    -Neurodevelopmental impairment - 30%
  2. Impact to DCDA twins
    -Risk of death of remaining twin - 15% (5-10%)
    -PTB - 50%
    -Abnormal antenatal cranial imaging - 15%
    -Abnormal postnatal cranial imaging - 20%
    -Neurodevelopmental impairment - 10%
    -Increased risk of CP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Discuss management of DC twins where one has died
-Causes (6)
-Monitoring (5)
-Reasons for delivery (2)
-Postnatal management (2)

A
  1. Causes
    -FGR - increased risk with discordance >30%
    -PET
    -Abruption, infection, anomalies, cord accidents
  2. Monitoring
    -Anti-D if RH negative
    -Weekly CTG
    -Fortnightly growth scans
  3. Reasons for delivery
    -Death of a DC twin is not a reason for delivery
    -Deliver if there is a condition affecting pregnancy as a whole - PET/DIC/ chorio
    -Delay delivery if possible till >34/40
    -Give steroids and MGSO4 as necessary
  4. Postnatal management
    -4-6 week postnatal MRI
    -Long term neurodevelopmental FU
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Discuss management when one MC twin dies in utero
-Incidence
-Causes
-Impact to surviving twin
-Management

A
  1. Incidence
    -Spontaneous demise in 1% of MC twins
  2. Causes
    -TTTS (50%), Selective FGR, Fetal anomalies, TRAP, cord entanglement
  3. Impact to surviving twin
    -Result in acute haemorrhage and anaemia in live twin
    -Can result in fetal heart failure
    -Can cause severe brain damage >25%
    -If occurs before 24/40 then high risk of second twin demise but less risk of brain damage
    -If occurs after 24/40 then less risk of second twin demise but increased risk of brain damage
  4. Management
    -Offer TOP if peri-viable
    -MRI 4-6/52 post fetal demise to assess fetal brain injury +/- feticide if intracranial pathology
    -Weekly USS with MCA-PSV
    -Weekly CTG
    -Aim delivery at 37/40
    -No point delivering early as damage already done unless acute concern for live twin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Discuss management of DCDA twins
-Antenatal (8)

A
  1. Antenatal management
    -Determine chronicity approx 14 weeks and do NT if desired
    -Consider LDA if additional risk factors for PET/IUGR
    -Aneuploidy screening MSS1/NIPT
    -OGTT for GDM
    -Monthly scans from 20/40
    -Check FBC at 20 - 24 weeks and 28 weeks
    -Manage FGR same as in singletons
    -Fe and folic acid supplementation for maternal anaemia
    -Educate around PTD and consider Cx length but no evidence for progresterone or Cerclage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Discuss management of monochorionic twins
-Antenatally
-Delivery mode
-Timing of delivery

A
  1. Antenatal management
    -Confirm chronicity before 14 weeks by USS
    -Consider Fe and folic acid supplement for maternal anaemia
    -Consider LDA if other risk factors
    -Offer screening MSS1/NIPT for aneuploidy. Discrepancy of NT and discordant CRL can be an early sign of TTTS
    -Monitor for PET with weekly BP and urinalysis
    -USS fortnightly from 16 weeks to evaluate for TTTS - look at fluid volume, bladder volume
    -Commenced UAPI and MCA PSV from 20 weeks or earlier if clinically indicated. Continue fortnightly until delivered
    -Detailed anatomy scan at 20 weeks. Increased anomaly rate
    -Advise women to report sudden increase in abdo girth or SOB. May be TTTS
    -Refer to MFM if concern for TTTS, TRAP, TAPS, sFGR
  2. Mode of delivery
    -Aim vaginal delivery if leading twin cephalic and no other complications in pregnancy
  3. Timing of delivery
    -36-37 weeks if no complications
17
Q

Discuss twin to twin transfusion syndrome
-Incidence (4)
-Pathophysiology (4)
-Contributing factors (3)
-Timing (2)
-Presentation (5)

A
  1. Incidence
    -15% of MCDA twins. Less in MCMA twins
    -Causes 17% of all perinatal deaths in twins
    -Causes 50% of deaths in MC twins
  2. Pathophysiology
    -TTTS includes TOPS (Classic TTTS) and TAPS
    -Deep placental AV / VA anastomoses of large vessels.
    -Results in large volume transfusion from one twin to another
    -Donor fetus is hypovolemic and hypo-perfused leading to oligouria and oligohydramnios
    -Recipient fetus is hypervolemic and hyperperfused leading to polyuria, polyhydramnios and cardiac failure and hydrops
  3. Contributing factors
    -Cord insertion
    -Relative share of placenta
    -Fetal growth discordance
  4. Timing of TTTS
    -Onset usually 20-30 weeks. Can be anytime even intrapartum
  5. Presentation
    -SOB, increased abdominal girth of mother
    -May see discordant CRL or NT at 14/40 but not predictive
    -Discordant DV and NT RR 21 for TTTS
    -Oligo and poly on USS
    -Discordant bladder volumes (suggests severe TTTS)
    -Cardiac dysfunction, hydrops in severe cases of TTTS
18
Q

Discuss twin to twin transfusion
-Staging (5)

A
  1. Staging - used Quintero staging. Based on USS finginds
    Stage I - DVP <2cm in donor sac, DVP >8cm in recipient sac (DVP >10cm after 20/40)
    Stage II - Fetal bladder in donor twin not visualised over 60mins of observation
    Stage III - Absent or reversed UAPI or reversed DV
    Stage IV - Fetal hydrops in one or both twins
    Stage V - Fetal demise of one or both twins
    NB: Growth discordance is not a feature in TTTS or staging
19
Q

Discuss management for TTTS
-General points (2)
-Management options (4)
-RANZCOG recommendations (5)

A
  1. General points (From RANZCOG guideline)
    -Manage in a tertiary setting
    -Offer referral to center with facilities for laser surgery
  2. Management options
    Expectant management
    -In mild or late onset (>26/40) TTTS can do expectant management.
    Intentional septostomy created monoamniotic - not used in practice as no benefit over amnioreduction
    Amnioreduction
    -Short term solution. Doesn’t fix underlying problem
    -May reduce risk of PTB and complications of polyhydramnios but increased risk of SROM, abruption, infection and can make laser more difficult.
    Laser photocoagulation
    -From 16-26 weeks
    -Interrupts anastomoses and functionally divides placenta into 2 regions.
    -Solomon technique reduces rates of TTTS and TAPS
  3. RANZCOG recommendations
    -Laser ablation is recommended for early onset severe TTTS
    -Early referral to appropriate centre is recommended when optimal treatment can be given before severe disease or short cx
    -Ongoing surveillance for TAPS post laser
    -Consider cord occlusion of one twin esp. if fetal anomalies
    -Can consider expectant management or amnioreduction in mild or late onset >26/40 TTTS
20
Q

Discuss outcomes for TTTS
-Without treatment (2)
-Rate of mortality in those treated at each stage
-Rate of neurological impairment in those treated

A
  1. Outcomes without treatment
    -90% mortality
    -50% neurological impairment in survivors
  2. With treatment - chance of one twin surviving
    Stage I - 91%
    Stage 2 - 88%
    Stage 3 - 67%
    Stage 4 - 50%
  3. Rate of neurological impairment - 12%
21
Q

Discuss TAPS - Twin anaemia polycythaemia sequence
-Pathophysiology (4)
-Incidence (2)
-Timing (1)
-Presentation (2)
-Management

A
  1. Pathophysiology
    -AV anastomoses of small vessels <1mm that are superficial in the placenta
    -Results in smaller volume transfusions
    -Can result from laser therapy for TTTS (10%)
    -Results in polycythemia for recipient and anaemia for donor
  2. Incidence
    -3-5% MC twins
    -10% after laser therapy for TTTS
  3. Timing
    -Usually occurs late in third trimester
  4. Presentation
    -Screen for anaemia with MCA PSV dopplers - >1.5MoM in donor and < 0.8 in recipient.
    -Screen in high risk groups - post laser therapy, sFGR, AbN UAPI, unexplained isolated polyhydramnios
  5. Management
    -Individualised management
22
Q

Discuss acute feto-fetal transfusion syndrome
-Pathophysiology (3)
-Outcomes (3)
-Management (3)

A
  1. Pathophysiology
    -Results from drop in heart rate or blood pressure in one twin leading to a sudden massive loss of blood from the acute donor twin
    -Similar to when one twin dies in MC twins
    -Recipient twin doesn’t necessarily demise
  2. Outcomes
    -Risk of death to donor twin 50%
    -Risk of death to recipient twin 15%
    -Risk of brain injury to recipient twin 20-30%
  3. Management
    -Delivery of surviving twin not indicated as damage done
    -MRI 4-6 weeks post event
    -Refer MFM
23
Q

Discuss selective growth restriction
-Definition (2)
-Incidence (2)
-Timing (1)
-Causes (3)

A
  1. Definition
    One twin has EFW <10th centile and there is >25% discordance between twins
    Categorised further based on diastolic flow - important for prognosis
  2. Incidence
    -10-15% of monochorionic twins
    -50% of those with TTTS
  3. Causes
    -Uneven sharing of placental territory
    -Varying cord insertions
    -Inter fetal anastamoses
24
Q

Discuss Classification of selective fetal growth restriction in twins.
-Classification types
-Delivery timing for each type
-Clinical features for each type
-RANZCOG recommendations on delivery timing (1)

A

GRATACOS classification - based on diastolic flow
Type I - Positive EDF in both twins
-Deliver >34/40
-90% survival
Type II - Persistent absent or reversed EDF
-High risk deterioration and IUD of FGR twin
-Deliver 29/40
Type III - Intermittent absent or reversed EDF
-Low risk hypoxia to FGR twin
-10-15% risk of unexpected IUD of FGR
-Aim delivery 32/40
2. RANZCOG recommendations
-Management strategies poorly defined and get expert advice +/- transfer to tertiary service

25
Q

Discuss twin reversed arterial perfusion (TRAP)
-Definition
-Incidence
-Cause
-Prognosis

A
  1. Definition
    -Acardiac twin perfused due to placental anastomoses with other twin acting as a pump
  2. Incidence
    -1% of monochorionic twins
  3. Causes
    -Death of one twin early in pregnancy
    -Reversed flow through cord to acardiac twin by pump twin via large AA anastomoses
    -Perfuses lower body of acardiac twin
  4. Prognosis
    -Untreated mortality 50%
    -Fetal cardiac failure from high output, hydrops, IUFD
26
Q

Discuss management of TRAP
-Diagnosis (1)
-Management (3)

A
  1. Diagnosis
    -Dopplers
  2. Management
    -Ref MFM
    -Treatment not required is no evidence of compromise to pump twin
    -Could consider cord occlusion or laser treatment
27
Q

Discuss monochorionic monoamnionic twins
-Incidence (1)
-Survival rate (1)
-Risks in pregnancy (2)
-Delivery mode and timing (1)

A
  1. Incidence
    1% of all twin pregnancies
  2. Survival rate
    60%
  3. Risks in pregnancy
    -Same risk but worse in MCMA twins + cord entanglement
  4. Delivery timing and mode
    -CS at 32-34 weeks
28
Q

Discuss timing of delivery for uncomplicated twins
-DCDA
-MCDA
-MCMA
-Triplets

A
  1. DCDA - 37 - 38/40
  2. MCDA - 36-37/40
  3. MCMA - 32/40
  4. Triplets 35-36/40
29
Q

Discuss risk of still birth
-Beyond 39/40 in DCDA
-Beyond 32/40 in MCDA
-How should pregnancies be managed if women decline planned delivery

A

1.IUD in DCDA twins >39/40 = 1:70
2.IUD in MCDA twins >32/40 = 1:23
3. If declining delivery should undergo:
-Weekly LV and dopplers and CTG
-Fortnightly growth

30
Q

Discuss mode of delivery of twins
-Factors for vaginal delivery (6)
-Factors for CS (6)

A
  1. Factors for VB in twins
    -Diamniotic twins
    -Leading twin cephalic
    -Forward flow of UAPI
    -More than 32/40
    -No obstetric contraindication to labour
    -Second twin is not >25% larger than leading twin
  2. Factors for CS in twins
    -Monoamniotic
    -Conjoined twins
    -Absent or reversed EDF
    -Leading twin breech
    -Higher multiples
    -Any other obstetric complication
31
Q

Discuss intrapartum care for twin delivery
1. General points (4)
2. Monitoring (3)
3. Analgesia (4)

A
  1. General points
    -IV access
    -Experienced obstetrician, anaesthetics, paeds, MW
    -Access to CS OT
    -Cross matched blood
  2. Monitoring
    -Continuous CTG. Can use FSC for first twin
    -Confirm presentation on arrival
    -If Twin 2 has CTG concerns before twin 1 born then offer section if VB not achievable in 20 mins
  3. Analgesia
    -Recommend epidural
    -Improves chance of vaginal birth
    -Enables quick recourse to CS
    -Enables IPV
32
Q

Discuss management of the second stage of twin delivery (6 points)

A
  1. Following delivery of first twin USS for presentation of second
  2. If second twin not cephalic: ECV if oblique, IPV to breech is transverse (IPV more successful 95% vs 40%)
  3. Consider oxytocin following delivery of first twin. Better outcomes with active managment
  4. Only ARM if required once PP in pelvis and engaged
  5. Delay cord clamping unless TAPS
  6. Active management of third stage
  7. Aim interval delivery of 30-60 mins. No hard fast rule but decrease in pH with increased duration of intertwin birth interval
33
Q

Discuss complications of twin delivery
-Retained second twin
-CS of second twin
-Locked twins

A
  1. Retained second twin - delivery >30mins post first twin
    -Results in second twin compromise as uteroplacental unit disrupted
  2. CS for second twin
    - occurs 5% of the time
    -Due to fetal distress, malposition, cord prolapse
  3. Locked twins
    -1:1000 twin deliveries
    -Head of leading breech locks with head of second twin which is cephalic
34
Q

Discuss the ELCS vs VB for twins RCT
-Aim (1)
-Study design (3)
-Primary outcomes (1)
-Secondary outcomes

A
  1. Aim:
    -To determine whether planned ELCS results in less adverse perinatal outcomes for twin delivery cf VB
  2. Study design
    -RCT in 25 countries
    -Women with twin pregnancies with leading first twin cephalic
    -Excluded MCMA twins, twins with contraindication to VB, twins with fetal anomaly, where twin B was substantially bigger than twin A
  3. Primary outcome
    -Composite measure of fetal and neonatal (d28) death or serious neonatal morbidity
  4. Secondary outcomes
    -Composite measure of maternal mortality and morbidity
35
Q

Discuss the ELCS vs VB for twins RCT
-Number included in the study (2)
-Results of primary outcome (3)
-Results of the secondary outcome (1)

A
  1. Number included in the study
    ~2800 women and 5600 fetuses
  2. Results of primary outcome
    -90% CS in ELCS group 43% in VB group
    -No difference in composite outcome between groups
    -No difference in subgroup analysis and composite measure so CS is not better in any subgroup e.g. very preterm, MCDA twins etc
    -Planned CS did not reduce the risk of worse outcomes for the second twin
  3. Results of the secondary outcome
    -No difference in the maternal composite outcome

RANZCOG 2024 - Antenatal (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions