Bariatric bed (600–1,000 lb capacity; 42–54 in width), with frame and trapeze for mobility
Chairs in room without sides
Bariatric operating table (600–1,000 lb capacity)
Larger belt or straps for securing legs to table
Toilet capable of accommodating 500+ pounds
Inflatable mattress
Extra-wide wheelchairs (400–700 lb capacity; 20–30 in width)
Extra-large inflatable sequential pneumatic compression devices
Bariatric surgical tray (for BMI >40 kg/m2)
Extra-long surgical instruments
Bookwalter self-retaining retractor
Long clamps
Appropriate size blood pressure cuff (or thigh cuff)
Ability to achieved central venous access if peripheral IV not feasible
Ability to place arterial line
Access to blood products (blood typed and crossed for transfusion)
Appropriate gown sizes
Extra personnel in delivery room
Labor in obese women has been shown to vary from that of normal-weight women, so standard provider expectations for cervical dilation and the threshold for cesarean delivery may need to be adjusted. In one observational study of 509 nulliparous patients, the rate of cervical dilation was inversely proportional to maternal weight [15]. In another study of nulliparous women, duration of labor was significantly longer for overweight and obese women than for normal-weight women, even when adjusting for other potential confounders, such as induction, oxytocin use, epidural analgesia, maternal weight gain, and fetal size [16]. In that study, the median duration of labor from 4 to 10 cm was 7.9 h for obese women, 7.5 h for overweight women, and 6.2 h for normal-weight women [16]. The etiology of the longer labor is not clear but does not appear to be the strength of uterine contractions. When intrauterine pressure was measured in 71 women during the second stage of labor, there was no difference in uterine contractility between three groups of women (normal, overweight, and obese women), although obese women labored longer during the active phase and a BMI greater than 25 kg/m2 was associated with a higher frequency of the need for oxytocin augmentation [17]. Future studies should examine reasons for the difference in labor patterns between women of different weight classifications. One hypothesis relates to increased soft tissue deposits in the pelvis of obese women, but this has not been demonstrated.
For practical purposes, however, clinicians need to understand that labor patterns may be dissimilar in overweight and obese women and thresholds for interventions (or lack of interventions) may need to be adjusted accordingly. An individualized approach to the overweight and obese parturient may result in fewer cesarean deliveries and the complications that might result. Additional challenges that may be encountered when an overweight or obese patient is laboring, include difficulty in monitoring the fetus and the contractions. A fetal scalp electrode and intrauterine pressure catheter may be needed to help guide labor management, especially in a patient with other complications during labor. Cardiovascular issues are also more common in obese women, and more intensive monitoring may be required than with normal-weight women.
Induction of Labor
With an increase in rates of labor induction for both medical and nonmedical indications, the risk-benefit ratio of induction specifically found in the overweight and obese population must be examined. The concepts of shared decision making discussed above are also applicable here. In situations where a medical indication exists for induction of labor, the benefits likely exceed the risks. However, elective induction of labor should not be undertaken without a candid discussion with the patient about risks and benefits, in a way she understands.
In a secondary analysis of a study in which women randomly received cervical ripening with 10 mg dinoprostone, 50 μg misoprostol, or 100 μg misoprostol, the median dose and duration of oxytocin required before delivery (3.5 units and 7.7 h) were significantly greater in obese women and extremely obese women (5.0 units and 8.5 h) as compared to the dose and duration (2.6 units and 6.5 h) in “lean” women (BMI less than 30 kg/m2) [18]. Furthermore, median time to delivery (27.0 h) was significantly longer in the extremely obese group (BMI over 40 kg/m2) than the “lean” group (22.7 h) [18].
The relationship is not clear-cut, however. In another retrospective cohort study of 29,224 women with prolonged pregnancy (defined as 41 and 3/7 weeks’ gestation or longer), there was no association of in length of labor, incidence of postpartum hemorrhage, shoulder dystocia, and neonatal outcomes with weight [19]. Obese women did have a significantly higher rate of cesarean delivery. For women undergoing their first delivery, the cesarean delivery rate was 38.7 % in obese women versus 23.8 % in normal-weight women. Future studies should also continue to examine labor patterns in overweight and obese women and how they differ from normal-weight women, so that abnormal labor can be better characterized and recommendations made for management of labor. Until then, providers should help the patient understand the evidence that exists and help her make an informed decision about undertaking elective induction of labor.
Cesarean Delivery
Given the growing epidemic of obesity and the increasing cesarean delivery rate, it is important to understand the relationship between obesity and risk of cesarean delivery. Both obesity and cesarean deliveries impact the public health. In a systematic review of 11 cohort studies specifically focused on nulliparous patients, the risk of cesarean delivery was increased by 50 % in women with BMI between 25 and 30 kg/m2, and the risk in women with BMI over 30 kg/m2 was more than twice that in women with normal BMI [3]. Although not included in that systematic review, a large population-based study reflected the findings from the review: in the population of nulliparous patients, the rate of cesarean delivery was 20.7 % for the normal BMI group, 33.8 % in the obese group, and 47.4 % for morbidly obese patients (≥35 kg/m2) [4]. In another prospective, population-based cohort study, 3,480 women with body mass index (BMI) over 40 kg/m2 had an increased risk of cesarean delivery, and women with BMI between 35.1 and 40 kg/m2 also demonstrated similar associations, but to a slightly lesser extent [1].
With the rapidly increasing numbers of obese and morbidly obese women, another population is growing in size, the extremely obese women (BMI ≥50 kg/m2). In a retrospective cohort study of 64,272 obese women, extremely obese women were found to have a number of worse outcomes, including higher risk of preeclampsia, macrosomia, cesarean delivery, neonatal hypoglycemia, neonatal length of stay greater than 5 days, and worse composite neonatal score [20]. Interestingly, in this population, 49.1 % of extremely obese women delivered by cesarean delivery (33.8 % of the extremely obese women had scheduled primary cesarean). The indications for the scheduled primary cesarean sections were not clear from this study, and the authors recommended further study to evaluate reasons for such high rates of elective cesarean delivery.
Anesthesia
Providers caring for overweight and obese women need to address potential anesthetic concerns, preferably before labor ensues. It should be standard practice to obtain an anesthetic consultation before planned cesarean section in an obese woman, and it is highly recommended in all obese women during the prenatal period, even if cesarean delivery is not scheduled. This is to account both for pain management during labor as well as to evaluate the patient to prepare for a possible difficult airway in the event of the need for general anesthesia.
In general, regional anesthesia is recommended for the overweight or obese patient in labor or for cesarean delivery. The identification of the epidural space in pregnant women, and particularly in overweight and obese women, can be extremely difficult. Even in the most controlled circumstance, for example in preparation for a scheduled cesarean delivery, complications are a possibility. In a cohort study of women undergoing elective scheduled cesarean delivery, women with BMI 50 kg/m2 or greater were most likely to have complications: 4 % had insufficient duration, 6 % required general anesthesia, and 3 % demonstrated intraoperative hypotension [21]. Overall anesthetic complications were 8.4 % in the extremely obese population as compared to 0 % in the normal-weight women [21]. It is important to counsel patients that such complications can also occur in a controlled, non-emergent situation, such as for an elective cesarean delivery. Decisions to perform elective procedures should not be made lightly.
Although not specifically focused on obese women, studies by Grau on the use of ultrasound to assist in skin-epidural space detection may be of utility in patients with difficult landmarks [22]. In one randomized controlled study of 300 parturients, women in the study group (who underwent ultrasonography for the identification of intervertebral structures and to determine depth and angle for placement of Tuohy needle) had fewer puncture attempts and were more likely to have complete analgesia and lower VAS (visual analog scale) pain score than those in the control group (typical placement without ultrasound). Ultrasound added 75 s to the mean preparation time. The rate of side effects (also including postpartum headache and backache) was lower, and patient acceptance was higher in the study group [22].
Ultrasound guidance is not without risk, as measurements may differ by millimeters between the image and actual depth. Anesthetic providers should still use standard procedures (e.g., loss of resistance (LOR) technique) to assist in placement of the epidural catheter. Obstetric providers may wish to discuss the option of ultrasound-guided epidural placement with anesthesia colleagues, especially for care of overweight and obese patients in their practices.
Regardless of the method used, discussing the benefits of epidural placement early in labor is worthwhile. Given the significantly increased risks of general anesthesia, such as difficult endotracheal intubation and intraoperative respiratory events, it is highly recommended that regional anesthesia is performed in a controlled setting without time pressures [2]. An obese patient without an epidural who requires an emergency cesarean delivery will likely require general anesthesia, resulting in potential further morbidity. Combined spinal-epidural is an ideal solution in an obese patient in labor, or spinal alone can be considered for the patient preparing for cesarean delivery.
Surgical Issues
Overweight and obese women may have an increased risk of intrapartum and postpartum hemorrhage, longer operative times, thromboembolic complications, postpartum endometritis, and wound infection [2]. Obese women undergoing cesarean delivery, whether elective, indicated, or emergency, are at increased risk for infectious complications [23]. Obese patients in one study were more likely to develop endomyometritis and wound infection, even if they received prophylactic antibiotics [23]. BMI and maternal obesity, in addition to length of labor and number of digital cervical examinations, remained significantly associated with infectious morbidity, even after multivariate analysis [23]. Based on their data, the authors recommend providers attempt to shorten labor to less than10 h and perform fewer than four digital exams in obese and overweight women to reduce risk of infection.
A broad-spectrum antibiotic, such as a first-generation cephalosporin, should be administered within 60 min preceding the skin incision. One consideration in extremely obese women is whether there is adequate tissue penetration. There have been no adequate studies in pregnant women to determine the correct dosing for overweight or obese women, but a recent study estimating the adequacy of antimicrobial activity of preoperative antibiotics found that cefazolin concentrations within adipose tissue obtained at skin incision were inversely proportional to maternal BMI [24]. Furthermore, in this study of women undergoing scheduled cesarean delivery who received 2 g of cefazolin at least 30 min before skin incision, a significant proportion of obese and extremely obese women did not have minimal inhibitory concentrations in adipose tissue when sampled at opening and closing of the incision [24]. Common practice is to administer 2 g of cefazolin in obese women (e.g., when BMI is >30 kg/m2) [2]. More studies are clearly needed to determine adequate dosing of antibiotics or the utility of adding a second antibiotic in this high-risk population.
Performing a cesarean delivery on an obese woman requires a clear understanding of anatomic relationships and a skilled surgeon to reduce operative complications. Obese women will often have a significant panniculus that needs to be taken into account in order to effectively deliver the infant in a safe and expeditious manner. Furthermore, obese women who undergo cesarean delivery are more likely than their normal-weight counterparts to have increased likelihood of wound breakdown and infection. There are differing opinions about the benefits of vertical versus horizontal skin incision, but there have been no prospective randomized trials to guide surgeons in this decision. The traditionally stated disadvantage to Pfannenstiel is reduced exposure and potentially more difficulty in delivering a macrosomic infant and difficulty in managing wound breakdown or infection after Pfannenstiel incision.
Several retrospective studies have attempted to answer this question. The incidence of wound complications was 12 % in one retrospective study, and the incidence of wound complications was greater (35 % vs. 9 %) in women with vertical skin incisions [25]. In another smaller case–control study, however, there were no differences in infections or other complications between women undergoing supraumbilical versus Pfannenstiel incisions [26]. In a large multicenter cohort study that examined only emergency cesarean deliveries (2,498 women in all), a vertical incision was found to reduce delivery incision-to-delivery interval by 1 min for primary and by 2 min for repeat cesarean but was associated with more frequent endometritis and postpartum transfusion [27].
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