These rates are significantly greater in obese women. In one study, the primary rate was 33.8 percent for obese and 47.4 percent for morbidly obese women. These values compare strikingly with the rate of only 20.7 percent for normal-weight gravidas (Weiss, 2004). In an analysis of 226,958 women, cesarean delivery rates rose signiicantly for overweight (34 percent), class I (38 percent), class II (43 percent), and class III (50 percent) obesity (Schummers, 2015). In the same study, rates of gestational diabetes, itself a risk factor for cesarean delivery, increased from 6 percent for women with a BMI <25 kg/mrto 21 percent for those with a BMI of ::40 kg/mr. More worrisome is that obese women also have higher rates of emergency cesarean delivery, and obesity lengthens times for decision-to-incision and for delivery (O'Dwyer, 2013; Pulman, 2015). Girsen and associates (2014) found significantly increased incision-to-delivery times for both emergent and nonemergent cases.
Discussed in Chapter 31 (p. 596), the incidence of failed trial oflabor after cesarean is higher in obese women (Grasch, 2017; Hibbard, 2006). Women who gain weight between pregnancies also have signiicantly lower rates of vaginal birth after cesarean.
IIIII \I.' I
FIGURE 48-8 Abdominal incision for the obese woman. A. Frontal view. The dotted line indicates an appropriate skin incision for abdominal entry relative to the panniculus. As shown by the uterus in the background, selection of this periumbilical site permits access to the lower uterine segment. B. Sagittal view.
For cesarean delivery, forethought is given to optimal placement and type of abdominal incision to allow access to the fetus and to efect the best wound closure. We prefer a vertical incision in obese women to provide the most direct access (Fig. 48-8). Others prefer a low transverse abdominal incision, with or without rostral taping of the pendulous abdomen. Individual diferences in maternal body habitus preclude naming anyrone approach as superior (tfcLean, 2012; Turan, 2016). Some observational studies have compared wound outcomes associated with vertical and transverse skin incisions, but results are conflicting as to a superiority of either (Brocato, 2013; Marrs, 2014; McClean, 2012; Sutton, 2016; Thornburg, 2012).
he frequency of abdominal wound infections is directly related to BM!. Conner and associates (2014) found the risk of wound infection is threefold higher for super-morbidly obese women compared with nonobese women-23 versus 7 percent. Among women with a BMI >45 kg/mr, wound complication rates range from 14 to 19 percent (Smid, 2015;
Stamilio, 2014). Comorbid diabetes apparently raises this risk (Leth, 201l). Other studies describe wound complication rates ranging from 2 to >40 percent in obese women (Conner, 2014; vIarrs, 2014; Smid, 2015; Thornburg, 2012).