What birthweight percentile is associated with optimal perinatal mortality and childhood education outcomes?

Birthweights between the 50th-93rd percentiles were most consistently associated with both low perinatal mortality and high reading and numeracy scores, suggesting that small for gestational age does not sufficiently capture the risks associated with variation in fetal growth. Our data indicate that the effect of birthweight percentile accounts for 1% of variation in perinatal and education outcomes.