A gravid woman may present in any stage of labor. Those with regular forceful contractions and the urge to push are in active labor (2nd stage) and may be near delivery. This stage begins when the cervix is fully dilated, which allows for the gradual descent of the fetal head toward the vaginal outlet. As the head approaches the perineum, the labia begin to separate with each contraction and recede once the contraction subsides. Crowning refers to separation of the labia by the head that does not recede at the end of the contraction. The appearance of crowning heralds imminent vaginal delivery. At this point, transfer from the ED is not advised and preparations for delivery should begin immediately.
Management and Disposition
Immediately obtain maternal intravenous access, begin continuous fetal monitoring, and prepare equipment for impending delivery and neonatal resuscitation (eg, suction, oxygen, warming light). Notify both obstetric and pediatric consultants of imminent ED delivery. Obtain important relevant history including gestational age, number of previous pregnancies, a diagnosis of twin/multiple gestations, prenatal care, and any problems with the pregnancy to date.
Most commonly, the fetus is facing toward the mother’s back. Extension of the fetal head occurs as it exits the vagina. During delivery of the head, support the maternal perineum with your hand and a clean, dry cloth to slow rapid fetal descent. This can reduce birth trauma to the mother. If needed, assist delivery of the fetal head by applying gentle pressure upward on the chin through the perineum (modified Ritgen maneuver) while simultaneously elevating the scalp to support head extension.
Once the head has been delivered, the occiput promptly rotates toward a left or right lateral position. At this stage, sweep the infant’s neck checking for a nuchal cord (umbilical cord wrapped around the fetal neck). A nuchal cord can disrupt uterine blood flow during contractions, possibly leading to fetal distress represented on tocometry by variable decelerations (Fig. 10.54). If a nuchal cord is identified, slip it over the infant’s head. If the cord is wrapped too tightly to be reduced and impedes delivery, it can be clamped and ligated on the perineum, followed by the immediate delivery of the shoulders and body.
Crowning. Descent of the fetal head with separation of the labia is known as crowning and heralds imminent vertex delivery. (Photo contributor: William Leininger, MD.)
If thick meconium is present, use a mechanical suction catheter for deep suctioning of the posterior pharynx and glottic region prior to delivery of the infant’s shoulders. Aspiration of thick meconium can lead to pneumonitis and hypoxia in the neonate. Inform consultants of the presence of any meconium detected.