Serum immunoglobulin levels in the course of normal gestation in Nigerian women.

The three major immunoglobulin (IgG, IgA and IgM) concentrations were measured in 118 Nigerian women during normal pregnancy. IgG was found to decline progressively throughout gestation with a very highly significant decrease between the first and second trimester (0.01 greater than P greater than 0.005) and between the second and third trimesters (P = 0.01). The mean concentrations of IgM were significantly lower in sera from first-trimester pregnant women than those of age-matched non-pregnant control subjects (P less than 0.001), and there was a further significant decrease between second and third trimester groups (0.005 greater than P greater than 0.001). No statistical difference was observed for IgA levels throughout normal pregnancy. The significance of these results is discussed in relation to other observations elsewhere.