Researchers led by Sarah Robertson at University of Adelaide are looking into the role played by white blood cells called macrophages in early pregnancy, according to a report published in the Journal of Clinical Investigation.
The team utilized a mouse model in which macrophages could be depleted immediately after embryo implantation. They found that without macrophages, embryos were unable to implant in the uterus. The failure to implant was thought to be caused by reduced levels of certain hormones, such as progesterone and vascular endothelial growth factors. Pregnancy could be completely restored by either the addition of macrophages or through administration of progesterone. These findings shed light on a new function of macrophages, as well as a potentially correctable cause of infertility.