The role of decidual NK cells in pregnancies with impaired vascular remodelling

- DNK cells isolated from pregnancies with high or normal uterine artery resistance indices.
- Normal-RI dNK regulate trophoblast invasion and spiral artery remodelling.
- High-RI dNK are less able to regulate trophoblast invasion and remodelling.
- Normal-RI and high-RI dNK differ in their receptor expression and production of secreted factors.

The pathologies of the dangerous pregnancy complications pre-eclampsia (PE) and fetal growth restriction (FGR) are established in the first trimester of human pregnancy yet we know little of how this happens. Finely tuned interactions between maternal and placental cells are essential for pregnancy to progress without complications; however, the precise nature of this cross-talk and how it can go wrong are crucial questions that remain to be answered. This review summarises recent studies examining the role played by natural killer cells in regulating normal placentation and remodelling. Their involvement when it is impaired in PE/FGR pregnancies will additionally be discussed.