The Italian Society of Fertility and Sterility and Reproductive Medicine (SIFES-MR) has issued new guidelines on 28 IVF add-ons, outlining which may help in certain situations, which lack evidence, and which should be limited to research.
NK cells
Researchers in a 2023 study review the use of 27 IVF add-ons and provide recommendations by ESHRE, with only several that are recommended or could be considered for the general infertility population.
This post covers the variety of reasons embryos can fail to implant or miscarry, including as a result of advanced maternal age, chromosomal translocations, lifestyle, endometritis, the microbiota, immunological issues, endometrial receptivity, the clinic, and more. Note that this is not a complete list, and will be updated periodically.
NK or natural killer cells play an important (and controversial) role in IVF. Most evidence suggests that there is no link to NK cell levels and pregnancy outcomes, and that immunotherapies that target NK cells in IVF show no benefit. Although there may be a certain group of patients that benefit. We’ll also discuss how uterine NK cells can support pregnancy, with information on their KIR receptors and HLA-C on the embryo, and how this can lead to embryo “rejection.” Finally, we’ll look at the overall problems with NK cell testing.