{"id":1397,"date":"2020-01-21T15:18:58","date_gmt":"2020-01-21T15:18:58","guid":{"rendered":"https:\/\/staging.theduff.co.uk\/?p=1397"},"modified":"2020-10-01T15:43:09","modified_gmt":"2020-10-01T15:43:09","slug":"zygote-embryo-blastocyst-foetus-ivf","status":"publish","type":"post","link":"https:\/\/theduff.co.uk\/zygote-embryo-blastocyst-foetus-ivf\/","title":{"rendered":"What’s the difference between<\/strong> a zygote, embryo, blastocyst and foetus?"},"content":{"rendered":"\n

NEWBORN, BABY, TODDLER, CHILD, TWEENAGER, TEENAGER, YOUNG ADULT, ADULT, MIDDLE-AGED, NO SPRING CHICKEN, ELDERLY…<\/strong> we love to give different names to humans as they get older and develop in some way. And it\u2019s no different for pre<\/em>-newborn stages, either. <\/p>\n\n\n\n

Here\u2019s what you need to know:<\/p>\n\n\n\n

Fertilisation<\/strong><\/h2>\n\n\n\n
\"Fertilised<\/figure><\/div>\n\n\n\n

When an egg is fertilised by sperm in the fallopian tube (or petri dish), it becomes a zygote<\/strong>. The zygote is a single cell that contains all 46 of the chromosomes needed to become a fully fledged human. A zygote is pretty much the first stage of human life. <\/p>\n\n\n\n

\"Zygote\"<\/figure><\/div>\n\n\n\n

(If you want to learn about pre-zygote terminology \u2013 like egg, oocyte, etc. \u2013 read this<\/a>.)<\/p>\n\n\n\n

24 hours after fertilisation<\/strong><\/h2>\n\n\n\n

The new cell divides in two for the first time and it\u2019s no longer called a zygote. Now it\u2019s an embryo<\/strong> (and you thought your twenties went by too quickly\u2026). It continues its journey through the fallopian tube towards the uterus, and divides in two yet again.<\/p>\n\n\n\n

\"Two-cell<\/figure><\/div>\n\n\n\n

Days 3\u20134 after fertilisation<\/strong><\/h2>\n\n\n\n

Providing you have a high-quality embryo, the cells of the embryo keep dividing in two every day as it travels through the fallopian tube \u2013 and for the first three or four of those days it\u2019s called a morula. <\/strong>So it\u2019s both an embryo and a morula \u2013 in the same way that a teenager is both a teenager and a pain in the butt.<\/p>\n\n\n\n

\"Morula\"<\/figure><\/div>\n\n\n\n
\"\"<\/figure><\/div>\n\n\n\n

<\/p>\n\n\n