If delivery of the head is already well on its way, the attending physician should prepare for the delivery after a stat call to obstetric and pediatrician staff. Ideally, the patient should be on the delivery table in the lithotomy position. If the patient is on a bed or stretcher, her legs should be supported. As time allows, the perineum may then be prepared by washing with mild soap and water and swabbing with povidone-iodine or chlorhexidine topical solution. Drapes should be placed over the patient, and the birth attendant should use gowns, masks, and gloves. The mother should be informed, assured, and instructed to enhance maternal cooperation to accomplish a controlled delivery. If the fetus is dead, there is no risk of further fetal trauma, and focus is totally on the mother.

After delivery of the head, the occiput promptly turns toward one of the maternal thighs, so that the head assumes a transverse position. The successive movements of restitution and external rotation indicate that the bisacromial diameter (transverse diameter of the thorax) has rotated into the anteroposterior diameter of the pelvis. The anterior shoulder should then be delivered by gentle downward traction in concert with maternal expulsive efforts. Traction should be exerted only in the direction of the long axis of the infant, because, if applied obliquely, it causes bending of the neck and excessive stretching of the brachial plexus. The posterior shoulder is then delivered by upward traction. Some practitioners, including the author, prefer to deliver the anterior shoulder prior to its external rotation (head-and-shoulder delivery) to avoid potential shoulder dystocia. The rest of the body almost always follows the shoulders without difficulty. A point of practical concern is the need to maintain control of the newly born infant such that inadvertent dropping does not occur.

To minimize the likelihood of aspiration of amniotic fluid debris, meconium, and blood that might occur once the thorax is delivered and the infant can inspire, the face is quickly wiped and the nares and mouth are aspirated (Fig. 12.2). A soft rubber ear syringe or its equivalent, inserted with care, is suitable for this purpose.

After delivery of the head and anterior shoulder, check for a nuchal cord by passing a finger around the fetal neck. A nuchal cord occurs in about 25% of cases and ordinarily does no harm. If a cord is felt, it should be drawn down between the fingers and, if loose enough, slipped over the infant’s head. If it is applied too tightly to the neck to be slipped over the head, it should be cut between two clamps only after delivery of the anterior shoulder and the infant should be delivered promptly.

The timing of cord clamping should be dictated by convenience, and cord clamping is usually performed immediately after delivery of infant. The cord is clamped after thoroughly clearing the infant’s airway, which usually takes about 30 seconds. The infant is not elevated above the introitus at vaginal delivery. The umbilical cord is cut between two clamps placed 4 or 5 cm from the fetal abdomen. Later, an umbilical cord clamp is applied 2 or 3 cm from the fetal abdomen. A segment of the umbilical cord is saved for blood gas analysis.

The placenta should be allowed to separate spontaneously. Immediately after delivery of the infant, the height of the uterine fundus and its consistency are ascertained. As long as the uterus remains firm and there is no unusual bleeding, the usual practice is to watch carefully for any of the following signs of placental separation.

These signs usually appear within 5 minutes. The mother may be asked to bear down, and the intra-abdominal pressure so produced may be adequate to expel the placenta. If these efforts fail, the attendant, again having made certain that the uterus is contracted firmly, lifts the fundus cephalad with the abdominal hand, keeping the umbilical cord slightly taut (Brandt-Andrews method). Aggressive traction on the cord risks uterine inversion, tearing of the cord, or disruption of the placenta, which can result in severe vaginal bleeding (2,3). As the placenta passes through the introitus, pressure on the uterus is stopped. The placenta is then gently lifted away from the introitus. Care is taken to prevent the membranes from being torn off and left behind. If the membranes start to tear, they are grasped with a ring forceps and removed by gentle traction. After removal of the placenta, the uterus should be massaged gently to promote contraction. The placenta, membranes, and umbilical cord should be examined for
abnormalities of cord insertion, confirmation of a three-vessel cord, and completeness of removal of placenta and membranes.

After delivery of the placenta, the primary mechanism by which hemostasis is achieved at the placental site is by a well-contracted myometrium. Oxytocin (Pitocin, Syntocinon, etc.), ergonovine maleate (Ergotrate), methylergonovine maleate (Methergine), and misoprostol (Cytotec) are used in various ways in the conduct of the third stage of labor, principally to stimulate myometrial contractions and thereby reduce the blood loss (Table 12.2).

Oxytocin, ergonovine, methylergonovine, and misoprostol are all used widely in the conduct of the normal third stage of labor, but the timing of their administration differs at various institutions. Oxytocin, and especially ergonovine, given before delivery of the placenta will decrease blood loss somewhat. However, the use of oxytocin, and especially ergonovine or methylergonovine, before delivery of the placenta may entrap an undiagnosed, and therefore undelivered, second twin. This may prove injurious, if not fatal, to the entrapped fetus. In most cases following uncomplicated vaginal delivery, the third stage of labor can be conducted with reasonably little blood loss.