The little heart begins to beat – with each beat becoming more regular as the days go by. This week, the embryo looks a lot more like a tadpole (including the little tail) than a human, but this will change soon. Some of the baby’s cells are developing in the neural tube, which will eventually become its spinal cord and brain. An incorrectly formed neural tube can result in a complication called spina bifida, where the spinal medulla doesn’t close completely – which highlights the importance of taking folic acid every day to fight this type of congenital disability.