This is not a surprise at all and it is definitely due to maturity and readiness. There is no way to push when a child becomes "ready to learn". He has always been behind developmentally.
We had our triplets through egg donation and surrogacy and two of the triplets inherited a genetic metabolic disorder.
They are weaker but it does not affect IQ or learning ability.

I guess if both affected boys needed to be delayed it would be less of a problem. In pre school they advanced each of the triplets forward into the next age group when they were ready individually and they NEVER advanced at the same time. We have been raising them as three individuals that happen to share a birthday and try not to refer to them as a unit but as individuals.

My main concern is on a social level how to handle this IF this happens. It is still too early and no final decision has been made but I want to be ready. We cannot push him forward just for social reasons that would lead to other social issues if he cannot keep up in class. Our eldest singleton is 8 1/2, he is in 3rd grade with ADHD and is one of the youngest boys in the class. We pushed him forward and have seen him struggle every year. We do not want to do that to this son.

We are looking for some realisitic support from families that understand multiple issues and how to handle this emotional issue if it comes to fruition in August. We want to be prepared to help prepare the kids.

Jay dad to BBB born 1-2-03 at 32 1/2 weeks
and singleton boy born 7-10-00
all through gestaional surrogacy and egg donation.