What about the impact of IVF on the definition of triplets or twins. For examplce, let say a women with the use of IVF creates ten viable embryos. During the first round of implantantion she gives birth to one baby. Then years later, she goes for another round of IVF using some of the frozen embryos from the intial fertization and gives birth to another baby. Well, technically, these babies were conceived at the same time but they were born years apart.
Are they twins/triplets, etc? Or is this definition strictly for those siblings who are BORN at the same time as opposed to being CONCEIVED at the same time.