The previously published version of this Article contained an error in Fig. 1 where the "HR low" and "HR high" labels were swapped.Furthermore, in Table 1 of this Article, the fifth row in the centre column contained a typographical error where the study population birth weight incorrectly read "2050 (1 450-2 650)", rather than "2050 (1450-2650)".These errors have now been corrected in both the PDF and HTML versions of the Article.