Management of Monochorionic Twin Pregnancy GTG Flashcards
What % of twins are Monochorionic?
30%
How common is TTTS in MCDA twins?
15%
Stage 1TTTS
What is the name of the scoring system?
Discordance in amniotic fluid
Donor Oligo, DVP <2cm
Recipient Poly DVP >8cm if before 20/40, >20 if after 20/40
Quintero system
Stage 2 TTTS
Donor twin: Bladder not visible due to anuria
Stage 3 TTTS
Doppler studies are abnormal in either twin
Donor: Umbilical arterial doppler velocity
Recipents: Venous doppler velocity
Stage 4 TTTS
Ascites, pericardial effusion, scalp oedema ot overt hydros in recipient
Stage 5 TTTS
One or both babies died
How common is TAPs in MCDA
2% uncomplicated MCDA
13% MCDA after laser treatment
What is TAPs?
Donor: Signs of fetal anaemia, increased MCA PSV >1.5 median
Recipient: Polycythaemia, MCA PSV <1.0 median
Without - oligo/poly
How common is growth discordance of >20%?
10-15% of MCDA Twins
What us stage 1 sGR (selective growth restriction)
Growth discordance but +ve diastolic velocities in both fetal umbilical arteries
What us stage 2 sGR (selective growth restriction)
Growth discordance with absent or reversed end-diastolic velocities AREDV in 1 or both foetus
What us stage 3 sGR (selective growth restriction)
Growth discordance with cyclical umbilical artery diastolic waveforms
How common is TRAP sequence in MCDA twins
1%
Was is TRAP sequence?
Acradiac twin being perfused by the anatomically normal twin through large artery-artery anastomnasis on placenta
How common is sGR in presence of TTTS?
50%
When should USS be performed to assess number of placenta?
11-13+6 (CRL 45-84mm)
Rate of fetal loss before 24. weeks in MCDA and DCDA twins?
MCDA 14%
DCDA 2.6%
Risk of false +ve combined screening with MCDA twins?
10% false +ve
90% sensitivity
(singleton 2.5%, DCDA twins 5%)
Sensitivity and false +ve for quadruple test MCDA
80% sensitive
3% false +ve
How often should MCDA twins be scanned?
Every 2 weeks from 16 weeks until delivery
What symptoms can the mother experience in TTTS?
Sudden increase in abdominal size, breathlessness
A discordance of how much is associated with increased risk of perinatal mortality?
> 20%
What treatment can be offered for TTS?
Amnioreduction or selective laser ablation
If TTS before 26 offered?
Fetoscopic laser abaltion normally offered at severe stage 1 or stage 2
Following Fetoscopic laser abaltion how often should USS be performed?
Weekly USS and serial UAPI, MCA PSV and ductus enosis doppler velocity
After 2 weeks, then 2 weekly
How often can recurrence TTS occur?
15% of Tx by fetoscopic laser abaltion, Solomon technique reduces chance
When should MCDA twin with TTS be delivered?
34-36 weeks
Consider steroids, usually by CS
If early onset sGR, what should be considered?
Selective reduction
When should Type 1 sGR be delivered?
Deliver by 34-36 weeks
When should Type 2-3 sGR be delivered?
Planned delivery by 32 weeks
If death of one twin in MCDA, what is the risk of death to surviving twin?
15%
If death of one twin in MCDA, what is the risk of neurological abnormality to surviving twin?
26%
What test should be requested in event of death of 1 twin?
Fetal MRI 4 weeks after co-twin demise to detect neurological morbidity
What test assess fetal anaemia?
Fetal MCA PSV using dopplers
What % of MCDA twins will delivery before 37 weeks?
60%
When is elective delivery of MCDA twin if no other indication for earlier delivery?
36/40
How much more likely is stillbirth in MCDA Vs DCDA
7 times
When should MCMA twins be delivered?
32-34 weeks
Risk cord entanglement
For selective reduction for MC twins, can selective fetocide be offered?
No - as placental anastomeses, offer intramural/umbilical cord abaltion
