Monoamniotic twins are identical or semi-identical twins that share the same amniotic sac within their mother's uterus.[1] Monoamniotic twins are always monochorionic and are usually termed Monoamniotic-Monochorionic ("MoMo" or "Mono Mono") twins.[1][2] They share the placenta, but have two separate umbilical cords. Monoamniotic twins develop when an embryo does not split until after formation of the amniotic sac,[1] at about 9–13 days after fertilization.[3] Monoamniotic triplets or other monoamniotic multiples[4] are possible, but extremely rare.[1] Other obscure possibilities include multiples sets where monoamniotic twins are part of a larger gestation such as triplets, quadruplets, or more.
- ^ a b c d "Monoamniotic Twins". Pregnancy info.net. Retrieved July 9, 2009.
- ^ "Mono Mono Twins". Twin Pregnancy and Beyond.
- ^ Shulman LS, van Vugt JM (2006). Prenatal medicine. Washington, DC: Taylor & Francis. p. 447. ISBN 0-8247-2844-0.
- ^ MoMo Twins; Monochorionic Monoamniotic Twins Archived 2016-04-08 at the Wayback Machine By Pamela Prindle Fierro, About.com. Retrieved on July 9, 2009