During embryo implantation, it interacts with and regulates the endometrium, and endometrial fluid secreted by the uterus nurtures the embryo. Such fluid contains particles of maternal microRNA, short molecular chains that affect the activation of certain genes in growing embryo. Perhaps this may be a reason why IVF babies are often alike their mothers, even though they weren't born out of oocytes carring their DNA.
You can take a peek at the study via this link