Regardless of the limit chosen, any group of SGA fetuses or babies include those that are physiologically / constitutionally small, and those that are pathologically small, i.e. growth restricted. Customising the standard adjusts for constitutional variation, improves identification of pathological smallness (FGR), and reduces false positive diagnoses. 1 4 5
1. Clausson B, Gardosi J, Francis A, Cnattingius S. Perinatal outcome in SGA births defined by customised versus population-based birthweight standards.
Br J Obstet Gynaecol. 2001;108(8):830–834. https://doi.org/10.1111/j.1471-0528.2001.00205.x
4. Figueras F, Figueras J, Meler E, et al. Customized birthweight standards accurately predict perinatal morbidity.
Arch Dis Child Fetal Neonatal Ed 2007;92:F277-80 https://fn.bmj.com/content/92/4/F277
5. McCowan LM, Harding JE, Stewart AW. Customized birthweight centiles predict SGA pregnancies with perinatal morbidity.
BJOG 2005;112:1026-33 https://doi.org/10.1111/j.1471-0528.2005.00656.x