Cord IgM levels in placentas with villitis of unknown etiology

Villitis of unknown etiology (VUE) is the largest category of the placental villitides and its incidence varies in different countries. The possibility that a higher incidence of intrauterine infection could explain the high frequency of VUE in developing countries led us to determine the incidence of raised IgM levels (a non-specific monitor to intrauterine infections) in cord serum of placentas with VUE. Eighty-six placentas were studied. Of these 67 were from infants with adequate weight for their gestational age (AGA) and 19 from infants small for their gestational age (SGA). IgM level in the cord serum was measured on radial immunodiffusion plates. VUE was found in 36 placentas (41.8%) and it predominated in the SGA group. Raised IgM levels were found in only 13.8% of the placentas with VUE. In spite of our frequency of VUE being high, our incidence of raised IgM levels in placentas with VUE was low and similar to that reported by authors who have low incidence of VUE in their series. We conclude that determination of cord IgM did not help significantly in the investigation of the cause of the high frequency of VUE in our series.