This letter responds to questions regarding the statistical analysis performed on the INTERGROWTH data.

Lancet Diabetes Endocrinol: Villar J, Altman DG, Victora CG, Bhutta ZA, Ohuma EO, Kennedy SH; International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st). Fetal growth and ethnic variation--authors' reply. Lancet Diabetes Endocrinol. 2014 Oct;2(10):774-5.