Peripheral nerve maturation in English, West Indian and Turkish newborn infants.

The ulnar and posterior tibial conduction velocities were measured in a group of normal full-term English, West Indian and Turkish infants. The English infants had a faster mean ulnar nerve conduction velocity than the West Indian and Turkish infants, but when the sex of the infants was taken into account only the male West Indian infant was found to have slower mean velocities. By three months of age the velocities were similar between the West Indian and English infants. This study emphasises the importance of taking account of the sex of infants in any developmental study.