Mammalian labor: variations on a theme by amniota

In this month’s issue of Endocrinology, Wada et al report on the “Role of vascular endothelial growth factor (VEGF) in maintenance of pregnancy in mice.” It’s a beautifully written report of a carefully performed series of experiments that strongly implicate a fall in the corpus luteum production of VEGF in the onset of labor in mice. However, the most intriguing and insightful aspect is the focus within the title on pregnancy maintenance.