Late decelerations are one of the precarious decelerations among the three types of fetal heart rate decelerations during labor. They are caused by decreased blood flow to the placenta and can signify an impending fetal acidemia. Definition Late deceleration is defined as a visually apparent, gradual decrease in the fetal heart rate typically following the uterine contraction. The gradual decrease is defined as, from onset to nadir taking 30 seconds or more.  A late deceleration typically follows a uterine contraction meaning, the onset, nadir and the return of the deceleration will follow the onset, peak and the return of a uterine contraction.[1]  Typically, late decelerations are shallow, with slow onset and gradual return to normal baseline. The usual cause of the late deceleration is uteroplacental insufficiency.