Furthermore, circulating SPINT1 concentrations at 24–34 weeks’ gestation was also correlated with uterine artery Doppler velocities (Fig. 3f) and placental surface area (Fig. 3g) measured by ultrasound at 22–24 weeks, that is, ultrasound findings from the mid-trimester (suggesting the early development of placental insufficiency) which preceded blood sampling by several weeks. Here, SPINT1 is linked to placental insufficiency.