Innervation of the placenta and uterus: Competition between cytotrophoblasts and nerves?

In normal pregnancy, invasion of the uterus by trophoblasts is followed by dramatic elimination of the rich uterine innervation present in the non-pregnant state, and by remodeling of maternal spiral arteries. In general, the healthy survival of vascular smooth muscle requires innervation, but whether denervation plays a role in stripping of vascular smooth muscle from spiral arteries in normal pregnancy has not been explored. We propose that the temporal and spatial association of trophoblast invasion with denervation in pregnancy may involve competitive interaction between the invading trophoblast and persisting neurons. We suggest feasible experiments to explore the possible effects of such trophoblast-nerve competition on spiral artery remodeling.