Can you tell by looking if baby has downs?

Many can/not always: Ds has a remarkably consistent set of physical features that a knowledgeable person will recognize in a newborn or older child. Yet in 3+ decades, I have seen a 21 trisomy that appeared more like a dwarf & 13 trisomy & an occasional ds kid with features so mild you would not suspect it.Physicians need to tell parents when they suspect such an issue, but testing is imperative to confirm it.