CHAPTER 54 Gary A. Dildy and Steven L. Clark Department of Obstetrics and Gynecology, Baylor College of Medicine Obstetrics and Gynecology, Service Chief MFM, Texas Children’s Hospital, TCH Pavilion for Women, Houston, TX, USA Your clinical options include all of the following, except: OVD became accepted in obstetric practice with the introduction of obstetric forceps during the eighteenth century and further evolved in the mid‐twentieth century with the development of the vacuum extractor [1, 2]. Forceps and vacuum assisted vaginal delivery are important components of contemporary intrapartum care and are accepted as methods to resolve prolonged second stage labor, suspected or potential fetal compromise, and to shorten the second stage of labor for maternal benefit (i.e. maternal cardiac, pulmonary or neurologic medical disorders) [3]. Since the late 1970s when OVD and cesarean delivery each constituted 15% of all births in the United States, there has been a continuing downward trend in rates of OVD accompanied by an increasing trend towards cesarean delivery [4]. As seen in Figure 54.1, by 2014 the cesarean delivery rate was 32.2% and the OVD rate was 3.2%, with the majority (2.6%) of all deliveries being vacuum assisted vaginal delivery and the minority (0.6%) being forceps assisted vaginal delivery. In 1992 the vacuum rate exceeded the forceps rate, and since 1998 both have declined steadily. Figure 54.1 Cesarean, forceps, and vacuum delivery rates in the United States (1970–2014) as a percentage of all births. Data for operative vaginal delivery before 1989 were not available. Source: Data were obtained from multiple resources at http://www.cdc.gov/nchs and are specifically cited in reference number [5]. The decreasing trend in OVD has contributed to the increasing trend in cesarean delivery, with its attendant immediate risks of immediate complications as well as downstream potentially catastrophic sequelae such as uterine rupture and placental percreta. Appropriate utilization of OVD has been proposed as one strategy to prevent the first cesarean in an effort to safely lower the cesarean rate [6, 7]. While there is no consensus regarding the optimal OVD rate, it is clear that there are valid clinical circumstances where OVD will safely expedite delivery for fetal benefit and avoid cesarean delivery for maternal benefit. In many circumstances, OVD can be performed more safely and quickly than can cesarean delivery. There are certain clinical scenarios where forceps provides a clear advantage over vacuum, for example, with rotational deliveries or in cases where a vacuum device may be subject to “pop‐off”, such as mid‐station deliveries. With forceps declining to a frequency of <1% of all U.S. births, concerns have arisen that adequate training during residency and maintenance of competency for practitioners will be compromised, and that forceps delivery may ultimately face extinction in the near future [5]. These national trends in OVD are also reflected in recent annual Accreditation Council for Graduate Medical Education (ACGME) national residency statistics reports (Figure 54.2), which show declining experience as OVD surgeon for OB/GYN residents; in recent years, OB/GYN residents exit training with a median of only 5 forceps and 16 vacuum deliveries during their four year training program. In 2012 the ACGME recommended a minimum threshold of 15 OVD procedures during OB/GYN residency [8]. For many graduating residents, experience with obstetric forceps and the vacuum extractor is insufficient to develop competency, and even if competent upon completion of residency, limited usage in clinical practice may preclude sufficient maintenance of competency. A decade ago, only one half of U.S. chief residents in OB/GYN programs reported feeling competent to perform forceps deliveries, and things appear to have deteriorated significantly since then [9]. Many graduating OB/GYN residents will likely neither perform forceps in practice, nor pass those skills to the next generation of obstetricians, thus perpetuating the problem. Figure 54.2 Median forceps and vacuum procedures for US Residents completing residency programs between academic years 2002–2003 and 2014–2015, as reported by the ACGME. In 2012–2013 data were reported cumulatively as operative vaginal delivery. Source: Data were obtained from http://www.acgme.org/Data‐Collection‐Systems/Case‐Logs‐Statistical‐Reports and are specifically cited in reference number [5]. Our purpose is to address the above concerns and propose evidence‐based recommendations towards optimizing patient safety for women who are candidates for OVD. For technical aspects of OVD, we would refer the reader to the many excellent textbook resources on this subject. Since there are maternal‐fetal benefits and risks to OVD (Table 54.1) with alternatives (i.e. expectant management and cesarean delivery), informed consent is essential to the performance of OVD procedures. Risks, benefits, and alternatives to OVD and contingencies for unsuccessful OVD should be discussed, and when possible, documented before the procedure in the medical record. One retrospective chart review of 100 cases of non‐emergent OVD reported that 61% had a general consent for OVD and 22% were given the option for cesarean delivery; maternal and fetal risks of OVD were documented in 3% and 0% of cases, respectively [10]. When delivery is not emergent, ideal informed consent would include a discussion of both maternal risks (e.g. lacerations, bleeding and bladder injury) and fetal injury (e.g. cephalohematoma, retinal hemorrhage), contrasted with the risks of the alternatives – cesarean or continued labor, as circumstances dictate. Such discussions and documentation may improve patient‐provider communication, clarify patients’ expectations, facilitate decision‐making in the setting of an acute intrapartum event, and reduce medical liability for the health care team. In life threatening emergencies, this discussion may be shortened, or in some rare cases (e.g. maternal cardiovascular collapse or cardiac arrest) skipped altogether. Table 54.1 Reported potential maternal‐fetal complications of operative vaginal delivery (OVD) and cesarean delivery a More prevalent with vacuum than forceps. b More prevalent with forceps than vacuum. One clinical scenario deserving special mention with regard to OVD informed consent is that in which major shoulder dystocia risk factors are evident. In 1978 Benedetti and Gabbe reported a 23% incidence in shoulder dystocia in the setting of prolonged second stage, mid‐pelvic delivery, and birthweight exceeding 4000 g [11]. Bearing in mind differences in clinical definitions (i.e. prolonged second stage, mid‐pelvic delivery) used in this study and a low incidence of diabetes in this patient population, it remains evident that the scenario of an OVD in the setting of prolonged second stage and suspected fetal macrosomia should prompt inclusion of shoulder dystocia and its complications in the discussion of alternative management, namely cesarean delivery. A retrospective case–control study of 100 cases of shoulder dystocia at term and 100 controls (singleton term vertex vaginal deliveries without shoulder dystocia) found that the combination of glucose intolerance, birth weight, and OVD were predictive in the occurrence of shoulder dystocia [12]. The major challenge with such models is that birth weight is known only after the fact and the imprecision of estimated fetal weight by any method, whether it be by physical exam, ultrasonography or “ask the parous mother” methods [13]. We do believe that consideration of the estimated fetal weight in conjunction with clinical pelvimetry, maternal diabetes status, and labor progress for risk assessment in the informed consent process for OVD. Thorough medical record documentation cannot be emphasized enough, especially in settings of greater risk, whether contemplating OVD, or managing complications such as shoulder dystocia. In a review of closed medical liability claims, Clark and colleagues showed that poor documentation of shoulder dystocia events with neonatal injuries contributed significantly to liability, underscoring the importance of accurate and detailed documentation [14]. Pre‐operative assessment of estimated fetal weight, clinical pelvimetry, adequacy of anesthesia, presence of an empty bladder and fetal station/position serve to reduce the occurrence of an unsuccessful OVD and improvident maternal‐fetal complications. Pre‐procedure checklists have been shown to be effective in reducing surgical complications and would seem applicable to procedures such as OVD [15]. There may be a tendency to forego checklists in acute emergencies for the sake of critical time, however, a clinical trial using high fidelity simulation of operating room crises such as massive hemorrhage and cardiac arrest showed checklist use to improve performance of critical steps and the potential to improve patient care [16]. Accurate and detailed pre‐procedure and post‐procedure documentation may benefit patient care, clinical research, peer review, and if needed, medico‐legal defense. Proposed elements of an OVD pre‐procedure note, pre‐operative checklist and post‐procedure note are found in Figures 54.3–54.4.
Operative vaginal delivery
Informed consent
Risk
Benefit
Maternal
Operative Vaginal Delivery
Cesarean Delivery
Operative Vaginal Delivery
Cesarean Delivery
Fetal
Operative Vaginal Delivery
Cesarean Delivery
Operative Vaginal Delivery
Cesarean Delivery
Pre‐procedure checklist and clinical documentation
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