• Somatomedin (SM) levels were measured by porcine cartilage bioassay, and growth hormone (GH) levels by radioimmunoassay in 52 full-term umbilical cord plasma samples and 28 maternal plasma samples. The SM levels in cord plasmas was 0.50 ± 0.19 units/ml (mean ± SD) compared to an adult standard plasma pool of 1.0 units/ml. The cord GH levels were 41.7 ± 36 mμg/ml. The low relative value of SM in the cord plasma is consistent with that found during early childhood, and may reflect a lower level of requirement. The high neonatal GH levels are hypothesized to be a compensatory increase to overcome factors suppressing SM production in fetal life.
(Am J Dis Child 131:1249-1251, 1977)
Hintz RL, Seeds JM, Johnsonbaugh RE. Somatomedin and Growth Hormone in the Newborn. Am J Dis Child. 1977;131(11):1249-1251. doi:10.1001/archpedi.1977.02120240067013