<prompt> Monoamniotic monochorionic twins are formed when division occurs: Repeat2 days2-8 days8 days2 weeks  <response>: Ans: C 8 days Ref: Dutta Textbook of Obstetrics 5th ed pg 200 Explanation: Dizygotic Twins 80 fraternal, binocular fertilization of 2 ova by 2 sperms during single ovarian cycle Monozygotic twins 20 identical, uniovular Twinning may occur at different periods after Fertilisation Division within 72 hrs --Diamniotie Diehorionic 30 - DAD Division 4-8 days Diamniotic Monochorionic 66 - DAM Division 8 days--Monoaniniotic Monochorionic 3 - MAM Division 2 weeks--conjoined twins 1 Siamese twins Thoracopagus Pyophagus Craniophagus Ischiophagus Remember: DAD - DAM - MAM 