ACOG Guidelines at a Glance: Operative vaginal delivery
Dr. Lockwood is Senior Vice President, USF Health and Dean, Morsani College of Medicine, University of South Florida, Tampa, FL, and Editor in Chief of Contemporary OB/GYN.
Operative vaginal delivery: A lost art
When I was a resident I performed more than 250 operative vaginal deliveries, mostly with forceps, and many after rotation. I suspect many practitioners of my generation compiled similar numbers during their training. Well, times have changed. Whereas in 1990 slightly more than 9% of livebirths resulted from either forceps delivery (5.11%) or vacuum extraction (3.9%), by 2014 only 3.21% of livebirths resulted from operative vaginal delivery and forceps accounted for less than 20% of these births (0.57% of all live births).1
The latest ACOG Practice Bulletin on this subject serves as an excellent summary of the indications, prerequisites, advantages, and overall safety of this increasingly lost art.2
Operative vaginal delivery is indicated for both maternal and fetal reasons. The former include exhaustion and ineffectual pushing in the second stage of labor as well as various medical and obstetrical factors requiring an expedited second stage. Such factors include preexisting cardiovascular disease, deteriorating medical conditions (eg, hypertension, sepsis), prolonged second stage of labor, arrest of descent or the need to rotate the fetal head to effect vaginal delivery. In cases of nonreassuring fetal heart rate (FHR) tracings, operative vaginal delivery may not only obviate the short- and long-term maternal morbidities of cesarean delivery but avoid progressive fetal ischemia.
While the Practice Bulletin retains the traditional classification system for outlet, low and mid-forceps deliveries (see Box 2), ACOG points out that in general, the lower the fetal head in the pelvis and the less rotation required, the less the risk of maternal and fetal injury. Vaginal birth is more likely to be achieved with forceps than with vacuum extraction, but the former has about twice the rate of associated 3rd- or 4th-degree perineal tears. However, despite this higher rate of perineal trauma, when compared with outcomes for cesarean delivery, forceps delivery was not associated with higher rates of pelvic floor or sexual dysfunction in primiparous women 1 year postpartum.3 In addition, no differences in bowel or bladder function were found between women delivered by forceps versus vacuum extraction at 5 years.4
The Practice Bulletin does caution against the routine use of episiotomy with operative vaginal delivery given its association with perineal trauma.
Forceps delivery has been associated with fetal facial lacerations and nerve palsy, ocular trauma, skull fractures and intracranial hemorrhage, while vacuum extraction has been linked to fetal scalp lacerations, cephalohematoma formation, subgaleal and retinal hemorrhage. Fortunately, all these risks are low. While neurological complications occur in 1 of 220 to 385 infants having operative vaginal deliveries, these rates must be compared to those delivered by, often emergent, cesarean section. For example, using seizure, intraventricular hemorrhage, and subdural hemorrhage as collective indicators of adverse neurologic outcome, forceps deliveries were associated with a reduced risk of such outcomes compared with both vacuum extraction (odds ratio 0.60; 95% CI: 0.40-0.90) and cesarean delivery (OR 0.68; 95% CI: 0.48-0.97).5