Extended INTERGROWTH-21^st Newborn Size Standards GAMLSS coefficients

A set of nested lists containing mu, sigma, nu and tau values across gestational ages for either sex, for the extended INTERGROWTH-21^st weight/length/head circumference-for-gestational age standards in newborns. The lists are ordered by acronym, then sex.

Source

Mu/sigma/nu/tau values were provided by Dr Eric Ohuma.

Note

The mu and sigma coefficients have been extrapolated by Simon Parker (with guidance from Eric Ohuma) to include a wider range of gestational ages, and should be applied carefully by researchers. More detail on the extrapolation process is available in an article on the package website.

References

Villar J, Cheikh Ismail L, Victora CG, Ohuma EO, Bertino E, Altman DG, et al. International standards for newborn weight, length, and head circumference by gestational age and sex: the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project. Lancet 2014, 384(9946):857-68. doi:10.1016/S0140-6736(14)60932-6

Villar J, Giuliani F, Fenton TR, Ohuma EO, Ismail LC, Kennedy SH et al. INTERGROWTH-21st very preterm size at birth reference charts. Lancet 2016, 387(10021):844-45. doi:10.1016/S0140-6736(16)00384-6

Villar J, Puglia FA, Fenton TR, Ismal LC, Staines-Urias E, Giuliani F, et al. Body composition at birth and its relationship with neonatal anthropometric ratios: the newborn body composition study of the INTERGROWTH-21st project. Pediatric Research 2017, 82:305-316. doi:10.1038/pr.2017.52

Examples

names(gigs::ig_nbs_ext_coeffs)
#> [1] "wfga"  "lfga"  "hcfga"
head(gigs::ig_nbs_ext_coeffs$wfga$male)
#>   gest_days       mu     sigma       nu      tau
#> 1       231 1.905973 0.4027349 1.095261 17.05299
#> 2       232 1.945933 0.4024603 1.095261 17.05299
#> 3       233 1.985389 0.4021894 1.095261 17.05299
#> 4       234 2.024345 0.4019221 1.095261 17.05299
#> 5       235 2.062806 0.4016584 1.095261 17.05299
#> 6       236 2.100775 0.4013983 1.095261 17.05299