IgG-subclass concentrations in cord sera from premature, full term and small-for-dates babies

IgG-subclass concentrations were determined in cord sera from 47 premature, 59 full-term, and 29 small-for-dates babies of varying gestational age. In permature and full term babies the relative percentages of all four subclasses were in the range for normal adult values. However, in small-for-dates babies significantly lowered IgG1-levels were found.