Knee-heel length measurement in healthy preterm infants

Abstract

Aim-To examine the reproducibility of crown-heel length measurement; the precision and reproducibility of knee-heel length measurement; and the association between the two in healthy preterm infants. Methods-Paired crown-heel and kneeheel lengths were measured on 172 occasions by three observers in 43 preterm infants between 205 and 458 days of postconceptional age. Results-Crown-heel length (CHL) measurement was highly reproducible, with a coeYcient of variation (CV) of 0.41%. Knee-heel length (KHL) measurement was relatively precise (CV 0.78%), but less reproducible (intra-observer CV 1.77%, intra-observer CV 2.11%), especially in larger infants. The association between KHL and CHL was not consistent and varied with age. KHL was a poor predictor of CHL, with a 95% predictive interval of ± 27.5 mm. Conclusions-KHL was less reproducible than CHL, especially in larger infants, and a poor predictor of CHL. (Arch Dis Child Fetal Neonatal Ed 1999;81:F50-F55)

Growth in the neonatal period after repeat courses of antenatal corticosteroids: data from the ACTORDS randomised trial

“…Indeed, it is interesting to note that even careful use of a neonatometer for length measurement did not reveal changes in length growth that were only detected using the much more accurate, though technically more difficult, approach of knemometry 23. The difficulties of accurate length measurement in infants are well recognised27 and may explain why previous studies have not detected differences in length at birth after repeat antenatal corticosteroids even when weight and head circumference were reduced 12…”

Feeding issues in preterm infants

“…Knee-heel length, as determined by knemometry, has therefore been used to assess linear growth in preterm infants 78 Still, recent data suggest that the relation between knee-heel and crown-heel length is not consistent, and the former is less reproducible than the latter when linear growth is being assessed 9. Further studies are needed to examine this critical issue more closely.…”

Improving growth in preterm infants during initial hospital stay: principles into practice

“…Yet, it is difficult to measure CHL in a precise and reproducible fashion 53. Measurement of knee–heel length has, therefore, been advocated54 but has not been confirmed as an accurate/precise indicator of total linear growth 55. The focus, therefore, has been on body weight because it can be accurately and reproducibly measured.…”