The effect of malarial chemoprophylaxis on immunoglobulin levels of pregnant Nigerian women and the newborn.

Immunoglobulins G, M and A were estimated at various stages of gestation in a group of 60 Nigerian primigravidae who were given malarial chemoprophylaxis throughout pregnancy. Immunoglobulin levels were also determined in paired maternal and cord sera of the same women at the time of delivery. Corresponding values for the malarial fluorescent antibody titres were also obtained. There was a fall in both the IgG levels and the fluorescent antibody titres with increasing gestation. The mean IgG and malarial fluorescent antibody titres were generally lower than those previously reported in Nigerian women not on malarial chemoprophylaxis. The mean cord IgG in this study was lower than the mean paired maternal IgG value. This agrees with reported studies in the African population but differs from those reported in Caucasians. The cord IgG values were correlated to the paired maternal IgG levels and those were found to be correlated with the corresponding malarial antibody titres. The factors that influence the fetomaternal IgG gradient are discussed. It is concluded that the newborn of mothers on prolonged malarial chemoprophylaxis may have a lowered acquired immunity to malaria.