Do identical twins always share a placenta?

Do identical twins always share a placenta? Short answer - No. I saw people arguing over this in the comment section of a twin video, so I thought I'd explain the three main types of twin pregnancies:

MoMo Twins (Monochorionic Monoamniotic)

→ 1 placenta, 1 sac

→ Always identical

→ Rare. higher risk due to cord entanglement and TTTS (twin to twin transfusion syndrome)

MoDi Twins (Monochorionic Diamniotic)

→ 1 placenta, 2 sacs

→ Always identical

→ Most common for identicals

 DiDi Twins (Dichorionic Diamniotic)

→ 2 placentas, 2 sacs

→ Can be fraternal OR identical!

→ usually the egg splits very early (before day 4 after conception), even identical twins can be DiDi

So, if someone says “Two placentas? Must be fraternal,” it’s not always true

Save or share if you’re a birth worker, twin parent, or just love geeky pregnancy facts!