Operative deliveries are vaginal deliveries accomplished with the use of forceps or a vacuum device. Once either is applied to the fetal head, outward traction generates forces that augment maternal pushing to deliver the fetus vaginally. he most important function of both devices is traction. In addition, forceps may also be used for rotation, particularly from occiput transverse and posterior positions.
According to the birth certiicate data from the National Vital Statistics Report, forceps-or vacuum-assisted vaginal delivery was used for 3.2 percent of births in the United States in 2014. his is a decline from 9.0 percent in 1990 (Hamilton, 2015). For these deliveries, a vacuum is disproportionately selected, and the vacuum-to-forceps delivery ratio is nearly 5: 1 (Merriam, 2017). In general, most of these attempts are successful. In 2006, only 0.4 percent of forceps trials in the United States and 0.8 percent of vacuum extraction attempts failed to result in vaginal delivery (Osterman, 2009).
If it is technically feasible and can be safely accomplished, termination of second-stage labor by traction instruments is indicated in any condition threatening the mother or fetus that is likely to be relieved by delivery. Some fetal indications include nonreassuring fetal heart rate pattern and premature placental separation (Schuit, 2012). In the past, forceps delivery was believed to be somewhat protective of the fragile preterm infant head. However, outcomes for neonates who 500 to 1500 g do not signiicantly difer if delivered spontaneously or by outlet forceps (Fairweather, 1981; Schwartz, 1983).
Some maternal indications include heart disease, pulmonary compromise, intrapartum infection, and certain neurological conditions. The most common are exhaustion and prolonged second-stage labor. However, a speciic maximum length beyond which all women should be considered for operative vaginal delivery has not been identiied (American College of Obstetricians and Gynecologists, 2016).
Operative delivery is generally performed from either a low or outlet station. Additionally, forceps or vacuum delivery should not be used electivey until the criteria for an outlet delivery have been met. In these circumstances, operative delivery is a simple and safe operation, although with some risk of maternal lower reproductive tract injury (Yancey, 1999).
Classiication for operative vaginal delivery is summarized in Table
It emphasizes that the two most important discriminators of risk for both mother and neonate are station and rotation. Station is measured in centimeters, -5 to 0 to +5.
TABLE 29-' . Operative Vaginal Delivery Prerequisites and Classification According to Station and Rotationa
Outlet forceps Scalp is visible at the introitus without separating the labia
Fetal head is at or on perineum
Head is OA or OP or
Head is right or left OA or OP position but rotation ;45 degrees
Low forceps (2 types) Leading point offetal skull is at station �+2 cm, and not on the pelvic floor, and: aClassification for the vacuum delivery system is the same as forforceps except that vacuum is used for traction but not rotation. bForceps, but not vacuum extractor, may be used for delivery of a face presentation with mentum anterior.
(Piper forceps may be used to deliver the head during breech delivery.
Zero station relects a line drawn between the ischial spines. Deliveries are categorized as outlet, low, and midpelvic procedures. High orceps, in which instruments are applied above 0 station, have noplace in contemporay obstetrics.