Twin Pregnancy😍

Summary of Contraindications in Twins

• Methylergometrine

• Vaginal delivery is C/I if
• 1st twin not cephalic
• MCMA
• Conjoint

• IPV - if previous CS

• Cerclage is C/I

Dizygotic Twins

• Dichorionic diamniotic (DCDA): Most common

• Better prognosis

• Incidence Factors:
• Geographical distribution
• Maternal family H/O twinning
• ↑ Maternal age & parity
• IVF & ovulation induction (Clomiphene citrate, hMG)

Monozygotic Twins

• Same: Sex, karyotype, HLA type, blood group

• Different: Fingerprints

• Incidence: 1 in 250 pregnancies (constant globally)

• Type based on division:

Timing (Days) (Add 4)	Twin Type
<4 days (Morula)	DCDA (Dichorionic Diamniotic) / Dizygotic Twins
4-8 days (Blastocyst)	MCDA (Monochorionic Diamniotic) ↳ most common
9-12 days	MCMA (Monochorionic Monoamniotic)
>12 days	Conjoint Twins M/C: Paraphagus > Thoracopagus L/C: Rachipagus > Craniophagus



IOC for chorionicity

• USG
• Done at 10-14 weeks POA

DCDA vs MCDA vs MCMA

 

 

• If D Present → Membrane present
• 2 D → Thick membrane
• 1 D → Thinner membrane

Fetal complications not seen in Twin Pregnancy

• Macrosomia

• Post term

• Monochorionic Diamniotic:
• T sign is present.
• Mnemonic: Modi → Motti → T sign

• Dichorionic Diamniotic:
• Lambda sign / Twin peak sign is present.
• Membrane is thick.
• Mnemonic:
• Laddu → Lambda → DD
• Twin peak → twins → di di

• Dichorionic Monoamniotic Pregnancy cannot exist.
• Mnemonic: Chorion → Ch → Hc → House; Amnion → room

Complications of Twin Pregnancy

Complications specific to monochorionic twins

• TTTS (Twin to Twin Transfusion Syndrome)
• Deep arterio-venous anastomoses

• TAPS (Twin Anemia Polycythemia Sequence)
• Donor → Anemia
• Recipient → Polycythaemia

• TRAP (Twin Reversed Arterial Perfusion)
• Arterio-arterial anastomosis

• Selective IUGR

• Single fetal demise

Complications specific to monoamniotic twins

• Conjoint twins

• Cord entanglement

TTTS

• Occurs due to deep arterio-venous anastomoses

Criteria for diagnosis of TTTS

• MCDA

• USG
• Donor twin: Oligohydramnios
• Recipient twin: Polyhydramnios

Complications of TTTS

Quintero Staging for TTTS

• Liquor → Bladder → Doppler → hydrops
• Stage 1: Oligohydramnios & Polyhydramnios
• Stage 2-: Absent UB in donor
• Stage 3: Anemia
• Abnormal Doppler study
• PSV of MCA:
• Donor twin: ≥ 1.5 mom
• Recipient twin: >0.8 mom
• Stage 4: Hydrops fetalis
• Stage 5: Fetal death

• Prognosis: Depends on recipient twin.

Management of TTTS

• < 28 weeks:
• In utero laser ablation of deep arterio-venous anastomoses

• ≥ 28 weeks:
• Serial amnioreduction (Larger twin)

TRAP

Pathophysiology

• Aberrant arterio-arterial anastomosis between:
• Normal heart (Twin A - Donor)
• Acardiac (Twin B - Recipient)

• Deoxygenated blood supplied to acardiac twin via umbilical artery

Outcome in Acardiac Twin

• Acardiac acephalus: Only lower part developed

• Acardiac amorphous: Amorphous mass (No parts developed)

Delivery in Twins

Cesarean Section Indications

• MCMA

• Conjoint twins

• TTTS, TRAPS

Vaginal Delivery Indications

• DCDA

• MCDA

• Note: Depends on presentation of 1st twin

DCDA & MCDA Specifics

• If 1st child not cephalic → CS

• If both twins cephalic:
• Vaginal delivery for both.
• Post 1st twin delivery:
• Do not give Inj. methylergometrine.
• Mnemonic: Methyl kidathath are? → Rich people, tension people, cardiac patients, twins ne

• If 1st cephalic & 2nd breech:
• 1st: Vaginal delivery
• 2nd: Assisted breech delivery

• If 1st cephalic & 2nd transverse lie:
• 1st: Vaginal delivery
• 2nd: Internal podalic version (IPV)
• Converts transverse lie to breech
• Followed by breech extraction.

Internal Podalic Version (IPV)

• Only indication: 
• 1st twin cephalic
• 2nd twin transverse lie

• Done in: OT

• Done under: General anaesthesia.

• Contraindication (C/I): Previous history of C-section.

VBAC (Vaginal Birth After Cesarean)

• Not C/I in twins.

• C/I if: 
• Previous history of C-section AND
• 2nd twin transverse lie
• since IPV is C/I in C-section

Active Management of Third Stage of Labour (AMTSL) in Twin Delivery

• Inj. Methergine: C/I.

• Inj. Oxytocin: Given.

• Common Fetal Complication
• Prematurity / preterm labour

• Cerclage
• C/I.

• Progesterone
• Not useful.

Special Features of Twin Pregnancy

Hellin's Rule

• If incidence of twins in a country is 1 in 80:
• Incidence of triplets: 1 in 80^2
• Incidence of quadruplets: 1 in 80^3

Superfecundation vs. Superfetation