Investigating fetal growth restriction and perinatal risks in appropriate for gestational age infants: using cohort and within-sibling analyses. - Cnattingius, S; Kramer, MS; Norman, M; Ludvigsson, JF; Fang, F; Lu, D; Kramer, M S; Ludvigsson, J F (BJOG: An International Journal of Obstetrics & Gynaecology, 2019)