These signs appear within minutes after newborn delivery, and the median time ranges from 4 to 12 minutes (Combs, 1991; Frolova, 2016; Shinar, 2016b). Once the placenta has detached from the uterine wall, the mother may be asked to bear down, and the intraabdominal pressure often expels the placenta into the vagina. These eforts may fail or may not be possible because of analgesia. After ensuring that the uterus is contracted irmly, the umbilical cord is kept slightly taut but is not pulled. Pressure is exerted by a hand wrapped around the fundus to propel the detached placenta into the vagina (Fig. 27-10). Concurrently, the heel of the hand exerts downward pressure between the symphysis pubis and the uterine fundus. This also aids inversion prevention. Once the placenta passes through the introitus, pressure on the uterus is relieved. The placenta is then gently lifted away. Care is taken to prevent placental membranes from being torn of and left behind. If the membranes begin to tear, they are grasped with a clamp and removed by gentle teasing (Fig. 27-11).
FIGURE 27-10 Expression of placenta. Note that the hand is not trying to push the fundus of the uterus through the birth canal! As the placenta leaves the uterus and enters the vagina, the uterus is elevated by the hand on the abdomen while the cord is held in position. The mother can aid in the delivery of the placenta by bearing down. As the placenta reaches the perineum, the cord is lifted, which in turn lifts the placenta out of the vagina.
FIGURE 27-11 Membranes that were somewhat adhered to the uterine lining are separated by gentle traction with ring forceps.
• Management of the Third Stage
Practices within the third stage of labor may be broadly considered as either expectant or active management. Expectant management involves waiting for placental separation signs and allowing the placenta to deliver either spontaneously or aided by nipple stimulation or gravity (World Health Organization, 2012). In contrast, active management of third-stage labor consists of early cord clamping, controlled cord traction during placental delivery, and immediate administration of prophylactic oxytocin. The goal of this triad is to limit postpartum hemorrhage (Begley, 2015; Jangsten, 2011; Westhof, 2013).
As noted earlier, delayed cord clamping does not increase postpartum hemorrhage rates, and thus early clamping is a less important component of this trio. Similarly, cord traction may also be less critical (Deneux-haraux, 2013; Du, 2014; Giilmezoglu, 2012). Uterine massage following placental delivery is recommended by many, but not all, to prevent postpartum hemorrhage. We support this with the caveat that evidence for this practice is not strong (Abdel-Aleem, 2010).
Therefore, utero tonics play an essential role to decrease postpartum blood loss. Choices include oxytocin (Pitocin), misoprostol (Cytotec), carboprost (Hemabate), and the ergots, namely ergonovine (Ergotrate) and methylergonovine (Methergine). In addition, a combination agent of oxytocin and ergonovine (Syntometrine) is used outside the United States. Also in other countries, carbetocin (Duratocin), a long-acting oxytocin analogue, is available and efective for hemorrhage prevention during cesarean delivery (Attilakos, 2010; Su, 2012). Of these, the World Health Organization (2012) recommends oxytocin as a first-line agent. Ergot-based drugs and misoprostol are alternatives in settings that lack oxytocin.