Genes within uterine gland cells shed light on potential causes of infertility

Even in the best-case scenario, when fertility clinics transfer chromosomally normal embryos into a would-be mother's uterus, the procedure only leads to a live birth half of the time. Some embryo transfers result in a pregnancy, and then miscarriage; but in 30 to 35% of cases, the embryo doesn't even implant in the uterus.