Twins

Di-zigotic, di-choronic, di-amnotic twins

• 2 fertilizations
  
• 2 placentas
  
• 2 sacs
  
• * can be two different genders

Mono-zigotic, di-chorionic, di-amniotic twins

• 1 fertilization that splits (0-3 days in tubal phase)
  
• 2 Placenta
  
• 2 Sacs
  
• * could be identical twins

Mono-zigotic, mono-chorionic, di-amniotic twins

• 1 fertilization that splits (day 4-8 blastocyst phase)
  
• 1 Placeta
  
• 2 sacs
  
• *Could have twin-twin transfusion

Mono-zygotic, mono-chorionic, mono-amniotic twins

• 1 fertilization that splits (day 9-12 = non conjoined, greater than 12 days conjoined)
  
• 1 placenta
  
• 1 sac
  
• * Could be conjoined twins

Twin-Twin Transfusion

• Smaller baby does better
  
• Bigger baby does worse because of increased in bilirubin