Do you know how a short period of hypoxia at birth could affect a child?

Minimal effect: Short periods of low oxygen at birth are not likely to have long term effects. As baby transitions into the first hour or two of life, they come from an environment (womb) where their o2 level was low by adult standards (70's) and modern devices often show quick drops below 50 during birth for brief periods. Those likely to show problems will often have a seizure ~24hrs reflecting injury.