Operative Vaginal Delivery
Operative vaginal delivery involves application of forceps or a vacuum extractor to the fetal head to assist during the 2nd stage of labor and facilitate delivery.
Indications for forceps delivery and vacuum extraction are essentially the same:
Prolonged 2nd stage of labor (from full cervical dilation until delivery of the fetus)
Suspicion of fetal compromise (eg, abnormal heart rate pattern)
Need to shorten the 2nd stage for maternal benefit—eg, if maternal cardiac dysfunction (eg, left-to-right shunting) or neurologic disorders (eg, spinal cord trauma) contraindicate pushing or maternal exhaustion prevents effective pushing
A prolonged 2nd stage is defined as follows:
Choice of device depends largely on user preference and operator experience and varies greatly. These procedures are used when the station of the fetal head is low (2 cm below the maternal ischial spines [station +2] or lower); then, minimal traction or rotation is required to deliver the head.
Before starting an operative vaginal delivery, the clinician should do the following:
Confirm complete cervical dilation
Confirm an engaged fetal vertex at station +2 or lower
Confirm rupture of membranes
Confirm that fetal position is compatible with operative vaginal delivery
Drain the maternal bladder
Clinically assess pelvic dimensions (clinical pelvimetry) to determine whether the pelvis is adequate
Also required are informed consent, adequate support and personnel, and adequate analgesia or anesthesia. Neonatal care providers should be alerted to the mode of delivery so they can be ready to treat any neonatal complications.
Contraindications include unengaged fetal head, unknown fetal position, and certain fetal disorders such as hemophilia. Vacuum extraction is typically considered contraindicated in preterm pregnancies of < 34 wk because risk of intraventricular hemorrhage is increased.
Major complications are maternal and fetal injuries and hemorrhage, particularly if the operator is inexperienced or if candidates are not appropriately chosen. Significant perineal trauma and neonatal bruising are more common with forceps delivery; shoulder dystocia, cephalohematoma, jaundice, and retinal bleeding are more common with vacuum-assisted delivery.