Twin pregnancy

Question 1

AN mx

Answer 1

M risk - GDM/PIH/PET/IOL/CS/PPH/PND/BF difficulties
F risk - congenital anom/sIUGR/TTTS/PTL/PTB

Mx
- MDI - Obs/MW/Diet
- Early OGTT
- Aneuploidy screening - cFTS vs NIPT
- Tertiary morph scan
- MC G/S q2wkly 16/40
- DC G/S q4wkly 24/40
- ANC q2wkly
- +/- LDA+/- Ca +/- Fe
- MOD - vaginal > CS
- Timing
DCDA 38/40
MCDA 37/40
MCMA 32/40

Question 2

Labour mx (including description of any maneuvers - presumably IPV)

Scenario 1 - twins in PTL

Scenario 2 - DCDA in SOL 37/40, uncomplicated AN course

Answer 2

PTB is a risk of twin pregnancy
Hx/Exam/Ix - confirm, ?reversible cause of TPL, anticipate/prep PTB
MDI is required - Paed/anaesthetic

• Hx - freq/duration/?PPROM/?APH/FM, urinary/bowel, RFs for TPL/PTL
• Exam - palp contraction +/- VE
• Ix - RTS +/- CTG/Bloods/urine
• T1 presentation/growth discordance -> guide MOD

If not in fully established labour
- Admission - tocolytic steroid loading +/- MgSo4 loading +/- antibiotics + analgesia
- Paed rv and formal G/S

If in fully established labour

1st stage
- IV Abx + MgSo4
- CEFM - FSE for T1
- Discuss risks of IPV, instrumental birth
- Pain relief options - epidural
- Discuss MOD preference - V > CS
- Discuss risks (emCS for 2nd twin)
- Identify CI to VD - (e.g. T1 breech, growth discordance >20% w larger T2 or >500g)
- MDI - paeds/anaesthetic

2nd stage
- Double clamp after birth of T1
- RTS to check position of T2 after birth - stabilize position +/- IPV
- Synt in room for 2nd twin for augmentation for hypotonic uterus
- Aim inter-twin delivery interval <30min
- OT/Neonates on standby
- IPV for delivery if T2 breech
(reach into uterus and grab fetal foot aiming to keep MI, delivery to vaginal introitus and follow with other foot, amniotomy once engaged, routine breech delivery with MSV or forceps for aftercoming head)

3rd stage
- anticipate PPH

Question 3

Fetal anomaly screen advice

Scenario 1 - new twin preg of 6 weeks
Scenario 2 - 43yo, IVF, DCDA

Answer 3

Aneuploidy options
- CFTS (include scan) 11-13+6 - preferred, provide individual risk, less accurate,
- NIPT - sensitivity as good as singleton albeit need validation, high failure rate, expensive, don’t provide individual risk,
- MSST - not recommended

Morphological abn options
- twin preg -> x2 risk of congenital abn -> tertiary center

Question 4

Mx of DCDA preg
with discordant growth/GDM

Answer 4

• discordance is >20% diff (as margin of error is 20%) or one twin is <10%
• Targeted Hx - AN course to date
• Aneuploidy/Morph - ? anomalies
• MDI - MFM, Obs Med, Paeds, DNE
• anatomy (?congen) vs doppler (? plac)
• 2 weekly scans - track growth
• weekly CTG/AFI/Doppler
• Screen for PET as (e.g. dipstick0
• optimize co-existing morb e.g. GDM
• modify RFs - smoking, nutrition
• timing of delivery = balance of rescuing IUGR fetus vs preterm delivery of normally grown fetus
• MOD of delivery CS if Twin B is 20% larger or >500g heavier
• Postpartum - LMO 6/52 OGTT

Question 5

Mx of early demise of 1 twin in preg
~12/40 or 15/40

Answer 5

Risks of co-twin demise
- agonal hypotension/TRAP (MC)
- death of co-twin
- reduction in BW
- growth restriction
- preterm birth

Management
- Tertiary center/MFM referral
- ?vascular flow to exclude TRAP
- USS+/MRB brain dmg (ventriculomeg)
- MCA surveillance (anaemia->IUT)
- Growth surveillance
? IUGR for surviving twin
? growth of demised twin (?TRAP)
- Consider IOL from 37/40 -> MOD obs indication
- Option for termination preg