ULTRASOUND APPEARANCE OF CONJOINED TWINS

• Single placenta without amniotic membrane (monochorionic, monoamniotic).
• Inseparable fetal bodies and skin contours.
• No change in relative position of fetuses,
• Both fetal heads are persistently at the same level.
• Bibreech (more common) / bicephalic presentation (cephalic-breech presentation is the most common presentation for omphalopagus).
• Polyhydramnios (± 50%).
• Umbilical cord:
• Single umbilical cord with >3 vessels.
• Two cords that originate separately that may fuse closer to their insertion.
• Number of vessels range from one artery and one vein to four arteries and two veins.
• Two types of malformations in affected fetuses:
• Malformations of conjoined organs probably due to the impaired twinning process.
• Malformations in non-conjoined organs that may or may not be related to the twinning process.

ULTRASOUND

• Link to Ultrasound Appearance Of The Various Types Of Conjoined Twins

Craniopagus at 10 wks GA: · Monochorionic twins with one yolk sac. · Fetuses joined at cranium. · Intrauterine demise

Video clip of Craniopagus at 10.5 weeks GA