The role of uterine natural killer cells in recurrent pregnancy loss and possible treatment options

This narrative review summarizes the current knowledge on the role of uterine natural killer (uNK) cells in recurrent pregnancy loss and possible treatment options. Recurrent pregnancy loss involves 2 or more consecutive miscarriages, affecting around 3% of couples attempting conception. Despite extensive investigation, causes often remain elusive. Uterine natural killer cells, critical in early gestation and implantation, may hold answers for treatment options. Properly designed and powered clinical trials are needed to provide more answers on the effect of treatment options in relation to uNK cells.