Question

When is an embryo called a foetus?

Answer 1

During each normal menstrual cycle, one ovum is released from one of the ovaries, about 14 days after the last menstrual period. Release of an egg is called ovulation. The egg is moved towards the end of one of the fallopian tubes. If the sperm penetrates into the egg, fertilization occurs.

Complete answer:
Once a month, an egg is released from an ovary into the fallopian tube. After sexual intercourse, the sperm moves from the vagina through the cervix and uterus to the fallopian tubes, where one sperm fertilizes the egg. The fertilized egg divides repeatedly as it moves down the fallopian tube to the uterus.
First, the zygote becomes a solid group/mass of cells. Then it becomes a hollow ball or mass of cells known as blastocyst. Then the cells divide and divide.
The next stage in development is formation of the embryo, which develops within the amniotic sac in the uterus only.
At the end of the 8th week after fertilization around 10 weeks of pregnancy, the embryo is considered now a foetus. During this stage, the structures/organs that have already formed will grow and develop further to make a complete baby.

An embryo is termed a foetus around the beginning in the 11th week of pregnancy, which in another way is the 9th week of development after fertilization of the egg with the sperm.

Note:
The developing baby has already gone through few changes in the very first few weeks of pregnancy. Generally, A zygote is a single-celled organism resulting from a fertilized egg.
The baby will be called an embryo from conception until the eighth week of development and After the eighth week, the baby will be called a fetus until it's born.