Immunoglobuliu M (IgM) levels were measured in 198 cord blood samples
from 192 apparently normal pregnancies from 24 weeks of gestation to t
erm. Simple linear regression analysis yielded a standard curve for Ig
M development during pregnancy shelving a 0.5 mg/dl increase in IgM pe
r week of gestation. This curve allows the comparison of fetal IgM lev
els from pregnancies considered to be at risk for intrauterine infecti
on.