Please note: This is a companion version & not the original book.Sample Book Insights: #1 The first few weeks after fertilization are a major hurdle for embryos, and many stop developing at some point during this time. Only about a third of fertilized embryos survive to become a baby.#2 The most common type of chromosomal abnormality is the addition of a copy of chromosome 21, which is what causes Down syndrome. However, sometimes a missing chromosome or more complex errors can also occur. An egg with the incorrect number of chromosomes is aneuploid.#3 The impact of chromosomal abnormalities on the chance of conceiving and carrying to term is especially apparent in the IVF context. If this factor is taken out of the equation, the pregnancy rates skyrocket.#4 Chromosomal screening is not a cure-all. It can reveal that none of the embryos created in an IVF cycle are chromosomally normal, which can result in no good embryo available to transfer.