Monoamniotic monochorionic twins are formed when division occurs: (Repeat)
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
<2 days
2-8 days
>8 days
>2 weeks