It was only in recent centuries physicians learned of the progress of the fetus within the womb and the duration of each stage as well as the discovery of the three surrounding amniotic sacks of fluid.
Kwakungenxa kuphela emakhulwini amuva odokotela bafunda ngentuthuko umbungu ngaphakathi esibelethweni kanye isikhathi ngasinye sigaba kanye kokutholakala abathathu ezungezile amasaka fluid uketshezi.