What happens to most zygotes with serious chromosomal problems?

The answer is: They will not continue with pregnancy, if baby is born they rarely survive beyond early childhood.

Most of the zygote with serious chromosomal problem will be dead before labor. A big genetic problem will cause the baby unable to survive. Most of the abortion at the first trimester pregnancy is happen because of the chromosomal problem. If the baby survive till labor they will still have some health problems and most will not survive long.