 In IVF pregnancies, incidences as high as one in 300 have been reported.The reasons for this association are not clear, but disturbed orientation of the blastocyst at implantation, vanishing embryos and the increased frequency of placental morphological variations in IVF pregnancies have all been postulated.It is recommended that women with vasa previa should deliver through elective cesarean prior to rupture of the membranes.