Umbilical cord length: clinical significance.

Umbilical cord length in 35,779 neonates was analyzed to determine values after mid-gestation and to see if abnormal values have clinical significance. Growth slowed after twenty-eighth week of gestation but did not stop before term. Cord length had a positive correlation with maternal height, pregravid weight, pregnancy weight gain, socioeconomic status, and the fetus being male. Short cords were associated with subsequent psychomotor abnormalities, but taken alone their predictive value was low because the normal range of cord lengths is large. Short cords were much better predictors of subsequent impairments when they were combined with other neonatal predictors. Short cords doubled or tripled the predictive values of low Apgar scores and several other neonatal abnormalities for subsequent low IQ values and neurologic abnormalities.