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    Management of cesarean delivery in the morbidly obese woman

    Q. The patient is a 32-year-old gravida 1 para 0 at 39 weeks with a fetus in breech presentation. She has a body mass index (BMI) of 49 kg/m 2 , and her pregnancy has been otherwise uncomplicated. External cephalic version was attempted at 37 weeks but was not successful, and she has been scheduled for primary cesarean delivery for breech presentation. How does the patient's weight affect the surgery?

    A. Today more than 35% of the population is obese, and obstetricians encounter the problem with increasing frequency.1 Obesity is defined as BMI ≥30 kg/m2 and further categorized as Class I: BMI 30-34.9 kg/m2, Class II: 35-39.9 kg/m2, and Class III: ≥40 kg/m2.2 Other terms used include severe (or morbid) obesity for those with BMI ≥40 kg/m2 and super (or super-morbid) obesity for BMI > 50 kg/m2. Because the term "morbid" obesity is considered pejorative by some, the other terms may be preferred. Obesity is a significant risk factor for pregnancy complications.3,4 Compared with women of normal BMI, obese women have twice the rate of primary cesarean delivery, emergency cesarean delivery, and wound infection. Wound complications have been reported to occur after 2.5% to 16% of cesarean deliveries in women of normal BMI but may occur in up to 30% of those who are obese.5,6

    What equipment does the physician need to prepare for surgery on an obese patient?

    Table 1 Typical capacity of selected hospital equipment
    Preparation for surgery on an obese patient should include the same steps as for an individual who is normal weight or overweight. However, specialized equipment may be useful, based on a patient's weight, physical dimensions, or both. Table 1 lists examples of the capacities of standard and bariatric beds, operating tables, and wheelchairs, underscoring the reality that standard hospital equipment may be inadequate to accommodate obese and morbidly obese patients. Physicians should also be aware that toilets, bedside commodes, and shower chairs also have weight limits. Table 2 lists other specialized equipment that may be needed to monitor or treat an obese patient.

    What are the anesthetic considerations in a pregnant woman who is obese?

    Table 2 Recommendations for cesarean delivery in obese women
    Anesthesia carries additional risks in the setting of obesity, and an anesthesiology consultation should be considered for women who are obese, particularly those with morbid obesity.7 It may be helpful to have this consultation before the onset of labor or a scheduled delivery because further testing (such as an EKG or evaluation for sleep apnea) may be recommended, and such evaluation may identify additional morbidities.

    Obese women who require a cesarean section during labor often already have had an epidural or combined spinal epidural.8 For cesarean delivery without pre-existing regional anesthesia, spinal anesthesia is usually preferable. Placement of an epidural catheter or spinal needle in an obese patient can be challenging because adipose tissue may obscure landmarks such as the midline and intervertebral space. Repeated attempts at needle insertion may be required, and the failure rate is higher.

    General anesthesia carries greater risk in pregnant patients than in those who are not pregnant. Normal anatomical changes in pregnancy (such as enlarged breasts, increased chest diameter, and airway edema) can make intubation more difficult.9 Obesity exaggerates these problems, and the likelihood of difficult intubation in obese pregnant women may be as high as 33%.8

    What type of surgical incision should be used?

    Obesity presents unique difficulties during surgery because the abdominal wall anatomy may be significantly distorted by a large pannus.10 The umbilicus is often located caudad from its normal anatomic position. In choosing the incision type and location, a surgeon should pay attention to the location of the symphysis pubis, iliac wings, and uterine fundus.

    An obstetrician has 2 choices of skin incisions: transverse incision or vertical. Appropriate choice in the obese patient continues to be widely debated but infrequently studied.10,11 A transverse incision can be placed either above or below the pannus. The advantages are increased wound strength, reduced postoperative pain, and improved respiratory effort. Retraction and exposure intraoperatively can be more difficult, however, and delivery of the fetus more awkward because of the presence of a large pannus. A major concern with a transverse incision in an obese patient is the potential for wound infection in the moist fold underneath the pannus. In contrast, a vertical incision may allow for better visualization of the operative field and the incision is out of moist skin folds and allows better exposure for wound care, perhaps decreasing infection risk. Because this incision may be more painful, it may compromise respiratory efforts in an obese postoperative patient.

    Table 3 Wound complication rates by skin incision type
    Contrary to conventional thinking, retrospective data suggest that vertical incisions are actually associated with increased rather than decreased risk of wound complications in obese women undergoing cesarean delivery compared with transverse incisions (Table 3).5,12 The available studies are limited by their lack of randomization and restriction to women more obese than class I. In one study, women who received vertical skin incisions also were heavier, more likely to have diabetes, and less likely to receive antibiotics—all of which are risk factors for wound infection. Nonetheless, available data suggest that a transverse incision should be considered and probably preferred for most obese women, even under a pannus (Table 2). Furthermore, vertical incision may not improve visualization of the lower uterine segment as expected, and it may increase the likelihood that a vertical hysterotomy will be required to deliver the infant.5 Transverse skin incision with a low transverse uterine incision also may make surgery faster and reduce blood loss and risk of infectious morbidity.

    To perform a transverse skin incision, the pannus often needs to be elevated and retracted cephalad.5 To assist with retracting the pannus, a surgeon can use elastoplast tape or Montgomery straps. Both surgeon and anesthesiologist must be aware that retraction of an extremely large pannus may be associated with cardiopulmonary compromise. The surgical incision then can be placed 2 finger-breadths superior to the pubic symphysis. The subcutaneous tissue in this area is relatively thin compared with other areas on the abdomen.

    What surgical techniques decrease risk of wound complications?

    Before surgery, skin cleansing to reduce bacterial colonization is particularly important in an obese patient. Once in the operating room, additional povidone-iodine or chlorhexidine may be required to cover the surface area. As in patients with normal BMI, the efficacy of skin preparation depends on adequate drying time (such as 3 to 5 minutes).

    Antibiotic prophylaxis at the time of a cesarean delivery reduces risk of postoperative maternal infection.13 Antibiotics should be given within 60 minutes before incision. An antibiotic that is effective against gram-positive and-negative bacteria, such as a first-generation cephalosporin, often is used.14 In general, standard doses of antibiotics are less likely to achieve therapeutic tissue levels in obese patients.15,16 In an obese woman, 2 g of cefazolin is recommended rather than 1 g. The utility of adding a second antibiotic for cesarean delivery prophylaxis in the setting of morbid obesity is an important question for future study.

    Drainage of the incision has been advocated as a surgical technique to decrease risk of wound complications. A meta-analysis of 6 studies comparing use of a wound drain versus no drain in 1640 women undergoing cesarean section found that use of a drain did not decrease wound complications.17

    Closure of the subcutaneous (SQ) tissue to decrease the amount of dead space has also been advocated as a technique to decrease wound complications in obese patients. A meta-analysis demonstrated that SQ closure in women with a fat thickness greater than 2 cm reduced wound disruption by 34%.18

    In a meta-analysis, when staples were compared to suturing of the skin incision, pain, cosmesis, and patient satisfaction were equivalent.19 Operative times were shorter with skin closure with staples. The risk of either a wound infection or separation was two-fold higher with staple closure. The results of this meta-analysis may not be generalizable to the obese population and this group should be specifically studied.

    Should perioperative DVT prophylaxis be used, and if so, what type?

    Scientific evidence is lacking to answer this question definitively, and most recommendations are based on expert opinion. Obesity and cesarean delivery are both risk factors for deep vein thrombosis.20 Early ambulation should be encouraged if a patient does not have a contraindication to it. Mechanical thromboprophylaxis, such as with pneumatic compression stockings, should be used peri- and intra-operatively. Pharmacologic thromboprophylaxis using either low-molecular-weight heparin (such as enoxaparin 40 mg daily) or unfractionated heparin (such as 5,000 every 12 hours) can also b considered, particularly in obese women who require cesarean delivery and have additional risk factors or BMI >40-50 kg/m2.

    Dr. Donna Johnson is professor and chair, Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston.

    This opinion was developed by the Publications Committee of the Society for Maternal-Fetal Medicine (SMFM) with the assistance of Donna Johnson, MD, and was approved by the Executive Committee of the Society on 8/7/2012. Neither Dr. Johnson nor any member of the Publications Committee (see the list of 2012 members at www.smfm.org) has a conflict of interest to disclose with regard to the content of this article.

    (Disclaimer: The practice of medicine continues to evolve and individual circumstances will vary. Clinical practice regarding the use of fetal fibronectin and transvaginal ultrasound cervical length screening may reasonably vary. This opinion reflects information available at the time of acceptance for publication and is not designed nor intended to establish an exclusive standard of perinatal care. This publication is not expected to reflect the opinions of all members of the Society for Maternal-Fetal Medicine.)


    1. Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of obesity in the United States, 2009-2010. NCHS data brief, no. 82. Hyattsville, MD: National Center for Health Statistics; 2012.

    2. National Heart, Lung, and Blood Institute (NHLBI) Obesity Education Initiative Expert Panel on the Identification, Evaluation, and Treatment of Obesity in Adults (US). Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report. Bethesda, MD: National Heart, Lung, and Blood Institute; 1998. Available at: www.ncbi.nlm.nih.gov/books/NBK2003/. Accessed August 29, 2012.

    3. Sebire NJ, Jolly M, Harris JP, et al. Maternal obesity and pregnancy outcome: a study of 287,213 pregnancies in London. Int J Obes Relat Metab Disord. 2001;25(8):1175-1182.

    4. Weiss JL, Malone FD, Emig D, et al; FASTER Research Consortium. Obesity, obstetric complications and cesarean delivery rate—a population-based screening study. Am J Obstet Gynecol. 2004;190(4):1091-1097.

    5. Alanis MC, Villers MS, Law TL, Steadman EM, Robinson CJ. Complications of cesarean delivery in the massively obese parturient. Am J Obstet Gynecol. 2010;203(3):271.e1-271.e7.

    6. Owen J, Andrews WW. Wound complications after cesarean sections. Clin Obstet Gynecol. 1994; 37(4):842-855.

    7. American Academy of Pediatrics, American College of Obstetricians and Gynecologists. Guidelines for Perinatal Care. 6th ed. Elk Grove Village, Ill: American Academy of Pediatrics; 2007.

    8. Tan T, Sia AT. Anesthesia considerations in the obese gravida. Semin Perinatol. 2011;35(6):350-355.

    9. Soens MA, Birnbach DJ, Ranasinghe JS, van Zundert A. Obstetric anesthesia for the obese and the morbidly obese patient: an ounce of prevention is worth more than a pound of treatment. Acta Anaesthesiol Scand. 2008;52(1):6-19.

    10. Alexander CI, Liston WA. Operating on the obese woman—a review. BJOG. 2006;113(10):1167-1172.

    11. Gunatilake RP, Perlow JH. Obesity and pregnancy: clinical management of the obese gravida. Am J Obstet Gynecol. 2011;204(2):106-119.

    12. Wall PD, Deucy EE, Glantz JC, Pressman EK. Vertical skin incisions and wound complications in the obese parturient. Obstet Gynecol. 2003;102(5 pt 1):952-956.

    13. Smaill F, Gyte GML. Antibiotic prophylaxis versus no prophylaxis for preventing infection after cesarean section. Cochrane Database Syst Rev. 2010;(1):CD007482.

    14. American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 120: Use of prophylactic antibiotics in labor and delivery. Obstet Gynecol. 2011;117(6):1472-1483.

    15. Edmiston CE, Krepel C, Kelly H, et al. Perioperative antibiotic prophylaxis in the gastric bypass patient: do we achieve therapeutic levels? Surgery. 2004;136(4):738-747.

    16. Pevzner L, Swank M, Krepel C, Wing DA, Chan K, Edmiston CE Jr. Effects of maternal obesity on tissue concentrations of prophylactic cefazolin during cesarean delivery. Obstet Gynecol. 2011;117(4):877-882.

    17. Gates S, Anderson, ER. Wound drainage for caesarean section. Cochrane Database Syst Rev. 2005;(1):CD004549.

    18. Chelmow D, Rodriguez EJ, Sabatini MM. Suture closure of subcutaneous fat and wound disruption after cesarean delivery: a meta-analysis. Obstet Gynecol. 2004;103(5 pt 1):974-980.

    19. Tuuli MG, Rampersad RM, Carbone JF, Stamilio D, Macones GA, Odibo AO. Staples compared with subcuticular suture for skin closure after cesarean delivery: a systematic review and meta-analysis. Obstet Gynecol. 2011;117(3):682–690.

    20. Varner MW. Thromboprophylaxis for cesarean delivery. Contemp OB/GYN. 2011;56(6):30-33.


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