<prompt> In utero infecion leads to which immunoglobulin?IgGIgAIgMIgD  <response>: IgM antibodies do not pass across the human placenta .Demonstrating IgM antibodies in a patients serum indicates recent infection, or in a neonates serum indicates intrauterine infection. Ref: Ananthanarayan Panikers textbook of microbiology 9th edition pg:99 