Who gives a crap what ancient Roman's thought? It is a dead language, their definitions are pointless and meaningless. A baby is an infant/a newborn, a fetus therefor is not a baby.
I'm a nurse and have to clarify the definitions thrown around. First stage is the fertilized egg. The fertilized egg, called a
zygote, divides repeatedly as it moves down the fallopian tube to the uterus. First, the zygote becomes a solid ball of cells. Then it becomes a hollow ball of cells called a blastocyst.
Inside the uterus, the blastocyst implants in the wall of the uterus, where it develops into an
embryo attached to a placenta and surrounded by fluid-filled membranes.
The next stage in development is the
embryo At this time, the embryo elongates, first suggesting a human shape. Shortly thereafter, the area that will become the brain and spinal cord (neural tube) begins to develop. The heart and major blood vessels begin to develop earlier—by about day 16. The heart begins to pump fluid through blood vessels by day 20, and the first red blood cells appear the next day. Blood vessels continue to develop in the embryo and placenta.
Almost all organs are completely formed by about 10 weeks after fertilization (which equals 12 weeks of pregnancy). The exceptions are the brain and spinal cord, which continue to form and develop throughout pregnancy. Most malformations (birth defects) occur during the period when organs are forming.
At the end of the 8th week after fertilization (10 weeks of pregnancy), the embryo is considered a
fetus By about 24 weeks: The fetus has some chance of survival outside the uterus. Six month of pregnancy.
The third difference between an embryo or fetus and a newborn baby is their place of residence.
Embryos and fetuses live inside the womb, and newborn babies live outside the womb.