OB's perform them

• Some pregnancy tests, for short
• Thin innermost membranous sac enclosing the developing embryo in higher vertebrates (Amniota reptiles
• Prenatal procedures performed by OBs
• Birds
• Mammals)
• Tests done by OBs

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Amnios \Am"ni*os\, n. Same as Amnion . [1913 Webster] ||

WordNet Word definitions in WordNet
n. thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals) [syn: amnion , amniotic sac ]

Wiktionary Word definitions in Wiktionary
n. (context anatomy English) amnion