<prompt> Which of the following statements concerning immunoglobulins is wrong:IgM does not cross placentaIgE increased in parasitic infectionIgM increased in primary responseFetal infection can be diagnosed by detection of IgG  <response>: Only IgG can cross placenta, other classes cannot cross placenta. Hence fetal infection cannot be diagnosed by IgG, IgM is the predominant antibody present in primary immune response. Levels of IgE are markedly raised in parasitic infections. 