R/standard_igb.R
igb_zscore2value.RdConvert birth measurements to INTERGROWTH z-scores/centiles (generic)
igb_centile2value(gagebrth, p = 50, var = "lencm", sex = "Female") igb_zscore2value(gagebrth, z = 0, var = "lencm", sex = "Female")
| gagebrth | gestational age at birth in days |
|---|---|
| p | centile(s) to convert (must be between 0 and 100) |
| var | the name of the measurement to convert ("lencm", "wtkg", "hcircm", "wlr") |
| sex | "Male" or "Female" |
| z | z-score(s) to convert |
For gestational ages between 24 and 33 weeks, the INTERGROWTH very early preterm standard is used.
International standards for newborn weight, length, and head circumference by gestational age and sex: the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project Villar, José et al. The Lancet, Volume 384, Issue 9946, 857-868
INTERGROWTH-21st very preterm size at birth reference charts. Lancet 2016 doi.org/10.1016/S0140-6736(16) 00384-6. Villar, José et al.
# get 99th centile for Male birth weights across some gestational ages igb_centile2value(232:300, 99, var = "wtkg", sex = "Male")#> [1] 3.095594 3.134276 3.172468 3.210176 3.247402 3.284150 3.320425 3.356229 #> [9] 3.391566 3.426440 3.460857 3.494817 3.528324 3.561383 3.593996 3.626168 #> [17] 3.657900 3.689198 3.720065 3.750502 3.780513 3.810103 3.839274 3.868027 #> [25] 3.896370 3.924301 3.951826 3.978946 4.005666 4.031988 4.057915 4.083450 #> [33] 4.108594 4.133353 4.157728 4.181721 4.205336 4.228576 4.251442 4.273939 #> [41] 4.296067 4.317829 4.339230 4.360270 4.380952 4.401281 4.421255 4.440879 #> [49] 4.460156 4.479087 4.497674 4.515922 4.533831 4.551403 4.568641 4.585547 #> [57] 4.602125 4.618375 4.634299 4.649901 4.665183 4.680145 4.694791 4.709122 #> [65] 4.723141 4.736849 4.750250 4.763343 4.776132