To provide accurate informed consent, understanding both maternal and neonatal risks and beneits with surgery is essential. In broad terms, cesarean delivery has higher maternal surgical risks for the current and subsequent pregnancies compared with spontaneous vaginal birth. his is balanced against lower rates of perineal injury and short-term pelvic floor disorders. For the neonate, cesarean delivery ofers lower rates of birth trauma and stillbirth but greater rates of initial respiratory diiculties.
For the mother, death attributable solely to cesarean delivery is rare in the United States. Even so, numerous studies attest to increased mortality risks. Clark and colleagues (2008), in a review of nearly 1.5 million pregnancies, found maternal mortality rates of 2.2 per 100,000 cesarean deliveries compared with 0.2 per 100,000 vaginal births. In a metaanalysis of 203 studies, Guise and coworkers (2010) reported a maternal mortality rate of 13 per 100,000 with elective repeat cesarean delivery compared with 4 per 100,000 women undergoing a trial of labor after prior cesarean.
Similar to mortality rates, the frequencies of some maternal complications are increased with all cesarean compared with vaginal deliveries. Villar and associates (2007) reported that maternal morbidity rates increased twofold with cesarean compared with vaginal delivery. Principal among these are infection, hemorrhage, and thromboembolism. In addition, anesthetic complications, which also rarely include death, have a greater incidence with cesarean compared with vaginal delivery (Cheesman, 2009; Hawkins, 201l). Adjacent organs infrequently may be injured, which is described in detail on page 583.
Women who undergo a cesarean delivery are much more likely to be delivered by a repeat operation in subsequent pregnancies. For women undergoing subsequent cesarean, the maternal risks just described are even greater (Cahill, 2006; Marshall, 2011; Silver, 2006).
As an advantage, cesarean delivery is associated with lower rates of urinary incontinence and pelvic organ prolapse than is vaginal birth (Glazener, 2013; Gyhagen, 2013a,b; Handa, 2011; Leijonhuvud, 2011). Rates of anal incontinence appear uninluenced by delivery route (Fritel, 2007; Nelson, 2010). Protective advantages persist to some degree over time, but cesarean delivery is not totally protective. Moreover, longitudinal studies suggest that initial pelvic floor advantages gained from cesarean delivery are lost as women age (Dolan, 2010; MacArthur, 2011, 2013; Nelson, 2010). To address this, the National Institutes of Health (2006) held a conference on cesarean delivery on maternal request. It summarized that stress urinary incontinence rates after elective cesarean delivery are lower than those following vaginal delivery. However, the duration of this protection is unclear, particularly in older and multiparous populations. This same panel considered the evidence implicating vaginal delivery in other pelvic loor disorders to be weak and not favoring either delivery route.