Intellectual and psychological performance in males born small for gestational age

All male singletons born without congenital malformations in Sweden between 1973 and 1978 and conscripted between January 1991 and January 1997 (n = 254426) were studied. Intellectual and psychological performance was tested at conscription. Males born small for gestational age (SGA) had lower results on both intellectual and psychological performance testing. Among males born SGA, low mean scores in both tests were constantly more common in those without catch-up growth than in those with catch-up growth. In conclusion, being born SGA is associated with an increased risk of subnormal intellectual and psychological performance. Catch-up growth is associated with a reduced risk of subnormal performance in males born SGA.