Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Difference in standardised test score (z score) and difference in IQ in conscription intelligence test by gestational age at birth compared with 40 gestational weeks among full brothers (same mother and father). Analysis is adjusted for relative birth weight, malformations, parental age, parental educational level, number of older siblings, and shared family factors
