The proposed mechanisms associated with risk factors which may contribute to Small for Gestational Age (SGA) and preterm births were explored in this presentation. Katz presents data from the Child Health Epidemiology Reference Group (CHERG). The following risk factors for SGA/preterm were highlighted in this presentation: height, body mass index (BMI) and weight gain during pregnancy, maternal age and parity, as well as time between births. Maternal short stature is strongly associated with both preterm and SGA births. There are statistically significant associations between low BMI/low weight gain and foetal growth restriction. Women younger than 18 years of age and nulliparous had a higher risk of SGA and preterm births than women aged 18–35 years old who had given birth only once or twice. There is an increased risk of both SGA and preterm births to mothers who have less than 18 months between births.