amniotic sac

(redirected from Birth sac)
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Related to Birth sac: yolk sac
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.amniotic sac - thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)amniotic sac - thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
amniote - any member of the Amniota
mammal, mammalian - any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk
fetal membrane - any membrane that functions for the protection or nourishment or respiration or excretion of a developing fetus
sac - a structure resembling a bag in an animal
References in periodicals archive ?
Emma Canning's daughters, Hannah and Sophie, were monoamniotic twins who shared the same birth sac and placenta.
Mr Canning said he felt like he had "won the lottery" when doctors delivered his daughters Hannah and Sophie who shared the same birth sac and placenta during pregnancy.
For Hannah and Sophie Canning shared the same birth sac and placenta - just one of 10 cases of "monoamniotic" twins in Britain each year.