Vasa praevia after IVF: should there be guidelines? Report of two cases and literature review.

The paper gives an illustration and reminder of the risk of problems with placentation resulting from IVF and embryo transfer. Reported here is one neonatal death related to vasa praevia when the condition was not diagnosed antenatally and a neonatal survival when vasa praevia was detected antenatally. A search of the English literature was performed using PubMed for 'vasa praevia and in vitro fertilization'. There were four articles that directly addressed this relationship. Case reports of IVF-embryo transfer pregnancies with vasa praevia and also studies that look at the incidence of vasa praevia in such pregnancies are included in this report. Hence, since vasa praevia is thought to be caused by a disturbed orientation of the blastocyst at implantation, it is probably related to the IVF-embryo transfer procedure. Screening of all IVF-embryo transfer pregnancies with transvaginal sonography and colour Doppler to rule out vasa praevia is recommended in the second trimester.