Completar frases CEDES19/20 - NAT6 - Unit3 Act3Versión en línea Complete the text about pregnancy with the missing words. por Javier David Panadero 1 foetus uterus placenta zygote amniotic embryo A fertilised ovum is called a . This is the first stage in pregnancy . It travels to the where the cells continue to divide and multiply until they become an . Then , it fixes itself to the lining of the uterus . After nine weeks the organs have started to develop and the embryo becomes a , which is protected by fluid and receives nutrients and oxygen through the . Pregnancy lasts about 280 days .