EFFECTS OF FEMALE SEX-HORMONES IN WHOLE-EMBRYO CULTURE

Much work has been done in vivo on the effects of sex steroids on the developing foetus. Many genital anomalies have been reported; defects of other organ systems have been suggested. Synthetic oestrogens are c onsidered to be developmental toxicants in vivo, while natural oestrog ens are thought to present little or no risk. A small selection of hor mones (17 beta-oestradiol, 17 alpha-ethynyloestradiol, diethylstilboes trol and progesterone) was tested using the rat whole embryo culture t echnique to see whether this difference could also be confirmed in vit ro. Dysmorphogenic embryotoxic effects were evident with both natural and synthetic oestrogens, but at much higher concentrations than would be expected to circulate in humans after therapeutic use.