From the photo [1] of the grandparents, they appear to be in their early fifties, so they are not elderly, frail or incapable of raising this baby. In Chinese culture, grandparents often take care of the children until the teenage years while the parents are working long hours, so there will be no Western-style stigma of having grandparents care for the child. I think it's a caring decision that they made to have the baby instead of destroying the embryo.

[1] http://www.scmp.com/news/china/society/article/2141048/baby-...