OBJECTIVETo study the relationship between the growth rate of the corpus callosum and neurological motor development in premature infants.

METHODSFifty infants whose gestational ages were less than 34 weeks and who were admitted to the neonatal intensive care unit from March 2007 to August 2007 were enrolled. From 0 to 6 weeks of postnatal age, the sagittal midline cranial sonography via anterior fontanel was performed, once weekly. The length and the morphology of the corpus callosum were measured. The 52-neuromotor examinations were performed at 3 months of corrected gestational age.

RESULTSThe mean length of the corpus callosum was 39.16 mm at birth. The mean growth rate of the corpus callosum during the first 6 weeks of life was 1.05 mm/week. Fourteen infants showed abnormal neuromotor development and 36 had normal-neuromotor function at 3 months of corrected gestational age. A decreased growth rate of the corpus callosum was observed in the abnormal nervimotion group between 2 and 3 weeks (0.68 mm/week vs 1.17 mm/week) and between 4 and 5 weeks (0.86 mm/week vs 1.12 mm/week) after birth compared with that in normal nervimotion group (p<0.05). The total growth rate of the corpus callosum from 2 to 6 weeks after birth in the abnormal nervimotion group was also lower than that in the normal nervimotion group (0.91 mm/week vs 1.15 mm/week; p<0.01).

CONCLUSIONSA neuromotor delay at 3 months of corrected gestational age may be associated with the decreased growth rate of the corpus callosum between 2 and 6 weeks of life in premature infants.