SMFM Consult Series Management of cesarean delivery in the morbidly obese woman Society of Maternal Fetal Medicine with the assistance of Donna Johnson, MD Published in Contemporary OB/GYN / oct 2012

Definition & Incidence  More than 35% of the population is obese, and obstetricians encounter the problem with increasing frequency.  Obesity is defined as BMI ≥30 kg/m2 and further categorized as:  Class I: BMI kg/m2  Class II: kg/m2  Class III: ≥40 kg/m2  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.  Obesity is a significant risk factor for pregnancy complications. 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?

What type of surgical incision should be used?  In choosing the incision type and location, a surgeon should pay attention to the location of the symphysis pubis, iliac wings, and uterine fundus.  2 choices of skin incisions: transverse incision or vertical. Appropriate choice in the obese patient continues to be widely debated but infrequently studied.  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.  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

Available evidence: What type of surgical incision should be used?  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.  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.  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.  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.  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.

DVT Prophylaxis  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.  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.

 The practice of medicine continues to evolve, and individual circumstances will vary. This opinion reflects information available at the time of its submission for publication and is neither designed nor intended to establish an exclusive standard of perinatal care. This presentation is not expected to reflect the opinions of all members of the Society for Maternal-Fetal Medicine.  These slides are for personal, non- commercial and educational use only Disclaimer

Disclosures  This opinion was developed by the Publications Committee of the Society for Maternal Fetal Medicine with the assistance of Stanley M. Berry, MD, Joanne Stone, MD, Mary Norton, MD, Donna Johnson, MD, and Vincenzo Berghella, MD, and was approved by the executive committee of the society on March 11, Dr Berghella and each member of the publications committee (Vincenzo Berghella, MD [chair], Sean Blackwell, MD [vice-chair], Brenna Anderson, MD, Suneet P. Chauhan, MD, Jodi Dashe, MD, Cynthia Gyamfi-Bannerman, MD, Donna Johnson, MD, Sarah Little, MD, Kate Menard, MD, Mary Norton, MD, George Saade, MD, Neil Silverman, MD, Hyagriv Simhan, MD, Joanne Stone, MD, Alan Tita, MD, Michael Varner, MD) have submitted a conflict of interest disclosure delineating personal, professional, and/or business interests that might be perceived as a real or potential conflict of interest in relation to this publication.