Table 7.
Variance components analysis for fetal, newborn infant, and childhood skeletal growth from the cohort of the INTERGROWTH-21st Project
| Variance | Fetal ultrasound measures16, % |
Size at birth16 (newborn infant lengtha), % | Infancy/childhood, % |
||
|---|---|---|---|---|---|
| 1st-trimester fetal crown-rump lengtha | 2nd- and 3rd-trimester fetal head circumference | Preterm infant length22 | Present study lengthb |
||
| Among study sites | 1.9 | 2.6 | 3.5 | 0.2 | 5.5 |
| Among individuals within a site | — | 18.6 | — | 57.1 | 42.9 |
| Residual | 98.1 | 78.8 | 96.5 | 42.7 | 51.6 |
Villar et al. Validation of the INTERGROWTH-21st fetal growth standards. Am J Obstet Gynecol 2018.
a
Variance between individuals for these measures could not be estimated, given the cross-sectional nature of the data
b
Includes length measurements at birth, 1 and 2 years, controlled for age and sex.