What are the causes of recurrent pre-implantation pregnancy losses?
An embryo may not implant either because there is something wrong with the embryo itself that it cant implant, or there is something in the uterine environment that doesnt allow a normal embryo to implant. • Problems with the embryo The most common abnormality found in pre-implantation embryos is an abnormal chromosome complement. Data from preimplantation genetic diagnosis suggest that 30% to 90% of in vitro fertilized eggs depending on maternal age are chromosomally abnormal. Furthermore, it has been estimated that 75% of karyotypically normal pre-implantation embryos fail to implant. Other than chromosomal abnormalities, problems with the pregnancies can include abnormal genes or abnormal DNA contributing to their losses. While mutations in HLA G genes have been associated with post-implantation recurrent pregnancy loss, secretion of soluble HLA G protein by pre-implantation embryos has been used to predict implantation potential of in vitro fertilized eggs before embryo transfer in
