much greater quantities of 16 alpha-hydroxyoestrogens ( e.g . oestriol ) than of 16-deoxyoestrogens ( e.g . oestradiol-17 beta ) are formed in human pregnancy than might be expected from the relative availability to the placenta of the 16 alpha-hydroxy- and 16-deoxy-c19 precursors .
C0014912
oestradiol-17 beta
C0032961
pregnancy