to study the steroid concentration in human amniotic fluid in early stages of pregnancy between 6-10 weeks , progesterone ( p4 ) , 17 alpha-oh-progesterone ( 17p4 ) , estrone ( e1 ) , estradiol ( e2 ) and estriol ( e3 ) levels in amniotic fluid ( af ) , maternal vein ( mv ) and chorionic tissue ( ch ) were measured by ria .
C0033308
progesterone
C0020387
17