For the mother, the final phase of labor still lies ahead. Empty of the child, the uterus retracts and grows smaller. It rests briefly, and in a few minutes’ time it begins its contractions again. The inside surface to which the placenta is attached diminishes markedly in area. The placenta, unable to contract, buckles and then tears free in the uterine cavity. The uterus continues to contract and expels the free placenta down into the vagina. This normally occurs without aid; usually a few minutes after delivery, sometimes before the third stage. The force of the uterine contractions drives the placenta partially out of the vagina and it is then delivered by the attending physician. It may be examined carefully for completeness, as placental material retained in the uterus could cause immediate or late hemorrhage if it should remain undetected.