acardius
noun
acar·dius
(ˈ)ā-ˈkärd-ē-əs 
: one of a pair of twin fetuses that develops without a heart and receives its blood supply from its twin through vascular connections on the placenta
… due to the parasitic relationship of the acardius, there is a high risk of mortality (50-75%) in the donor twin …—
Ona Marie Faye-Peterson et al., Handbook of Placental Pathology
Ona Marie Faye-Peterson et al., Handbook of Placental PathologyCite this Entry
“Acardius.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/acardius. Accessed 4 Nov. 2025.
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