Management of Monochorionic Twin Pregnancy GTG

Question 1

What % of twins are Monochorionic?

Answer 1

30%

Question 2

How common is TTTS in MCDA twins?

Answer 2

15%

Question 3

Stage 1TTTS

What is the name of the scoring system?

Answer 3

Discordance in amniotic fluid
Donor Oligo, DVP <2cm
Recipient Poly DVP >8cm if before 20/40, >20 if after 20/40

Quintero system

Question 4

Stage 2 TTTS

Answer 4

Donor twin: Bladder not visible due to anuria

Question 5

Stage 3 TTTS

Answer 5

Doppler studies are abnormal in either twin
Donor: Umbilical arterial doppler velocity
Recipents: Venous doppler velocity

Question 6

Stage 4 TTTS

Answer 6

Ascites, pericardial effusion, scalp oedema ot overt hydros in recipient

Question 7

Stage 5 TTTS

Answer 7

One or both babies died

Question 8

How common is TAPs in MCDA

Answer 8

2% uncomplicated MCDA

13% MCDA after laser treatment

Question 9

What is TAPs?

Answer 9

Donor: Signs of fetal anaemia, increased MCA PSV >1.5 median
Recipient: Polycythaemia, MCA PSV <1.0 median

Without - oligo/poly

Question 10

How common is growth discordance of >20%?

Answer 10

10-15% of MCDA Twins

Question 11

What us stage 1 sGR (selective growth restriction)

Answer 11

Growth discordance but +ve diastolic velocities in both fetal umbilical arteries

Question 12

What us stage 2 sGR (selective growth restriction)

Answer 12

Growth discordance with absent or reversed end-diastolic velocities AREDV in 1 or both foetus

Question 13

What us stage 3 sGR (selective growth restriction)

Answer 13

Growth discordance with cyclical umbilical artery diastolic waveforms

Question 14

How common is TRAP sequence in MCDA twins

Answer 14

1%

Question 15

Was is TRAP sequence?

Answer 15

Acradiac twin being perfused by the anatomically normal twin through large artery-artery anastomnasis on placenta

Question 16

How common is sGR in presence of TTTS?

Answer 16

50%

Question 17

When should USS be performed to assess number of placenta?

Answer 17

11-13+6 (CRL 45-84mm)

Question 18

Rate of fetal loss before 24. weeks in MCDA and DCDA twins?

Answer 18

MCDA 14%
DCDA 2.6%

Question 19

Risk of false +ve combined screening with MCDA twins?

Answer 19

10% false +ve
90% sensitivity

(singleton 2.5%, DCDA twins 5%)

Question 20

Sensitivity and false +ve for quadruple test MCDA

Answer 20

80% sensitive
3% false +ve

Question 21

How often should MCDA twins be scanned?

Answer 21

Every 2 weeks from 16 weeks until delivery

Question 22

What symptoms can the mother experience in TTTS?

Answer 22

Sudden increase in abdominal size, breathlessness

Question 23

A discordance of how much is associated with increased risk of perinatal mortality?

Answer 23

> 20%

Question 24

What treatment can be offered for TTS?

Answer 24

Amnioreduction or selective laser ablation

Question 25

If TTS before 26 offered?

Answer 25

Fetoscopic laser abaltion normally offered at severe stage 1 or stage 2

Question 26

Following Fetoscopic laser abaltion how often should USS be performed?

Answer 26

Weekly USS and serial UAPI, MCA PSV and ductus enosis doppler velocity

After 2 weeks, then 2 weekly

Question 27

How often can recurrence TTS occur?

Answer 27

15% of Tx by fetoscopic laser abaltion, Solomon technique reduces chance

Question 28

When should MCDA twin with TTS be delivered?

Answer 28

34-36 weeks
Consider steroids, usually by CS

Question 29

If early onset sGR, what should be considered?

Answer 29

Selective reduction

Question 30

When should Type 1 sGR be delivered?

Answer 30

Deliver by 34-36 weeks

Question 31

When should Type 2-3 sGR be delivered?

Answer 31

Planned delivery by 32 weeks

Question 32

If death of one twin in MCDA, what is the risk of death to surviving twin?

Answer 32

15%

Question 33

If death of one twin in MCDA, what is the risk of neurological abnormality to surviving twin?

Answer 33

26%

Question 34

What test should be requested in event of death of 1 twin?

Answer 34

Fetal MRI 4 weeks after co-twin demise to detect neurological morbidity

Question 35

What test assess fetal anaemia?

Answer 35

Fetal MCA PSV using dopplers

Question 36

What % of MCDA twins will delivery before 37 weeks?

Answer 36

60%

Question 37

When is elective delivery of MCDA twin if no other indication for earlier delivery?

Answer 37

36/40

Question 38

How much more likely is stillbirth in MCDA Vs DCDA

Answer 38

7 times

Question 39

When should MCMA twins be delivered?

Answer 39

32-34 weeks
Risk cord entanglement

Question 40

For selective reduction for MC twins, can selective fetocide be offered?

Answer 40

No - as placental anastomeses, offer intramural/umbilical cord abaltion