Sequential instrumentation most often involves an attempt at vacuum extraction followed by one with forceps. his most likely stems from the higher completion rate with forceps compared with vacuum extraction noted earlier. This practice significantly increases risks for fetal trauma (Dupuis, 2005; Gardella, 2001; Murphy, 2011). Because of these adverse outcomes, the American College of Obstetricians and Gynecologists (2015) recommends against the sequential use of instruments unless there is a "compelling and justifiable reason."
As the rate of operative vaginal delivery has declined, so have opportunities for training (Fitzwater, 2015; Kyser, 2014). In
FIGURE 29-2 Simpson forceps have fenestrated blades, parallel shanks, and English lock. The cephalic curve accommodates the fetal head.
many programs, training in even low and outlet forceps proce dures has reached critically low levels. For residents completing training in 2015, the Accreditation Council for Graduate Med ical Education reported a median of only five forceps deliveries, and that for vacuum deliveries was 16.
Because traditional hands-on training has evolved, residency programs should have readily available skilled operators to teach these procedures by simulation as well as through actual cases (Skinner, 2017; Spong, 2012). And, the efectiveness of simulation training has been reported (Dupuis, 2006, 2009; Leslie, 2005). In one program, maternal and neonatal morbidity rates with operative delivery decreased after the implementation of a formal education program that included a manikin and pelvic model (Cheong, 2004). In another, a 59-percent increase in forceps deliveries over 2 years was related to a single experienced and proactive instructor assigned to teach forceps to residents in labor and delivery (Solt, 2011).
Forceps refers to the paired instrument, and each member of this pair is called a branch. Branches are designated left or right according to the side of the maternal pelvis to which they are applied (Fig. 29-2). Each branch has four components: blade, shank, lock, and handle (Fig. 29-3). Each blade has a toe, a heel, and two curves. Of these, the outward cephalic curve conforms to the round fetal head, whereas the upward pelvic curve corresponds more or less to the curve of the birth canal. Some blades have an opening within or a depression along the blade surface and are termed enestrated or pseudoenestrated, respectively. True fenestration reduces the degree of head slippage during forceps rotation. Disadvantageously, it can increase friction between the blade and vaginal wall. With pseudo fenestration, the forceps blade is smooth on the outer maternal side but indented on the inner fetal surface. he goal is to reduce head slipping yet improve the ease and safety of application and removal of forceps compared with pure fenestrated blades. In general, fenestrated blades are used for a fetus with a molded head or for rotation. In most situations, however, despite these subtle diferences any are appropriate.
he blades are connected to shanks, which may be parallel or overlapping. Locks are found on all forceps and help to connect
FIGURE 29-3 Luikart forceps have pseudofenestrated blades, overlapping shanks, sliding lock, tongue groove handles. The pelvic curve is marked in this example by the black line.
the right and left branches and stabilize the instrument. They can be located at the end of the shank nearest to the handles (English lock), at the ends of the handles (pivot lock), or along the shank (sliding lock). Although varied in design, handles, when squeezed, raise compression forces against the fetal head. hus, forces to consider include traction and compression.