Super obesity in pregnancy: difficulties in clinical management


As the obesity pandemic continues in the United States, obesity in pregnancy has become an area of interest. Many studies focus on women with body mass index (BMI) 30 kg m−2. Unfortunately, the prevalence of patients with BMI 50 kg m−2 is rapidly increasing, and there are few studies specifically looking at pregnant women in this extreme category. The purpose of this article is to highlight some of the challenges faced and review the literature available to help guide obstetricians who might encounter such patients.


In 2009 to 2010, more than one-third of adults in the United States were obese (body mass index (BMI) 30 kg m−2).1 Perhaps, a more startling statistic is the increasing prevalence of morbid and super obesity (BMI 40 and 50 kg m−2, respectively). In a report looking at these groups in the United States between 2000 and 2005, the prevalence of self-reported BMI over 50 kg m−2 increased by 75%.2 The heaviest BMI groups have been increasing at the fastest rates for 20 years; consequently, the obstetrician will be caring for more super obese women. Obesity has long been perceived as a risk factor for poor pregnancy outcomes,3, 4, 5 but data on super obesity are limited. We recently cared for 34-year-old G1P0 with a prepregnancy weight of 630 lb (BMI 98.67 kg m−2). The purpose of this article is to highlight some of the challenges faced and review the literature available to help guide obstetricians who might encounter similar patients.

Definition of obesity

The World Health Organization (WHO) defines obesity as a BMI of 30 kg m−2.6 Obesity is subdivided into three classes: class 1 includes those with a BMI of 30 to 34.9 kg m−2, class 2 includes BMI of 35 to 39.9 kg m−2 and class 3 includes those with a BMI of 40 kg m−2.7 In the surgical literature, class 3 obesity is often further divided into morbid obesity for BMI of 40 to 49.9 kg m−2 and super obesity for BMI >50 kg m−2 (Table 1).4 Although commonly seen and used throughout medical literature, these definitions are not standardized, and authors have used varying BMI values to define the same term. Furthermore, there are no terms in the literature to address patients such as the one we encountered with a BMI approaching 100 kg m−2.

Table 1 Obesity definitions

Pathophysiology of obesity

Obesity is usually caused by an excessive intake of calories in relation to energy expenditure over a significant period of time. Increases in body fat results from even minor, but chronic, differences between energy intake and energy expenditure. In 1 year, the ingestion of only 5% more calories than expended can promote the gain of 10 lb in adipose tissue.8 Weight depends on the complex interaction between genetic background and environmental factors. Genetic background explains only an estimated 40% of the variance in body mass.9 Genetic heritability plays a significant role in obesity with the risk of childhood obesity significantly increased if one parent is obese and even higher if both parents are affected.10 Obesity is likely to result from the interaction of many different gene–gene and gene–environment interactions. The use of the genome-wide association approach has identified many genes with robust associations but usually with only modest contributions to overall genetic susceptibility to obesity.11 In contrast, a small number of single-gene mutations have been identified that clearly cause obesity in rare patients. Environmental factors such as diet and exercise play an important role in the development of obesity. The significant increase in obesity since the 1980s is largely secondary to alterations in environmental factors that increase energy intake and reduce physical activity. Reasons for this include more meals are eaten outside the home, there is greater availability of fast food and snack foods, serving sizes are larger and daily physical activity has decreased because of sedentary lifestyles.

Obesity is commonly associated with alterations in metabolic function, specifically insulin resistance, diabetes, dyslipidemia and increased blood pressure. Obesity is also associated with a long list of pregnancy complications. In general, the higher the patient’s BMI, the higher the chance of complication. This ‘dose-response’ has been well demonstrated for pre-eclampsia with the risk doubling with each 5 to 7 kg m−2 increase in prepregnancy BMI;12 in addition, for each 1 unit increase in pregravid BMI, the risk of cesarean delivery increases by 7%.13 Given this, patients should be counseled to attempt to be as close to ideal body weight before pregnancy and practitioners should have higher index of suspicion for pregnancy complications the higher the patient’s BMI.

Developmental origins of health and disease

There is growing evidence linking maternal prepregnancy BMI and gestational weight gain to offspring adiposity throughout life, from infancy through adolescence and to adulthood.14, 15 It has been suggested that the obesogenic environment experienced before and during conception and early pregnancy may induce methylation differences,16, 17 causing changes in gene expression, tissue structure and organ development. These changes may result in subsequent cardiometabolic health consequences in the adult offspring.18 Given this possible developmental origin of obesity, preconception weight loss should be emphasized and strongly encouraged.

Preconception weight loss

The American College of Obstetricians and Gynecologists encourages preconception counseling for the obese patient, including education about the maternal and fetal risks of obesity in pregnancy, and encouragement to participate in a weight reduction programs including diet, exercise and behavior modification before conception.5 There are limited data addressing preconception counseling and weight loss; however, recent studies in the primary care setting reassure us that preconception weight loss is achievable. The Louisiana Obese Subjects Study (LOSS) showed that when primary care physicians were trained to implement structured diets, group counseling and pharmacotherapy to treat patients with extreme obesity (BMI 40 to 60 kg m−2), over 30% achieved 5% weight loss over 24 months.19 Results of the practice-based opportunities for weight reduction (POWER) study at the University of Pennsylvania indicate that primary care practitioners, working with medical assistants, can provide effective weight management in patients with BMI of 30 to 50 kg m−2. Quarterly provider visits and medical assistant counseling, along with meal replacements and medications, was effective in inducing 5% weight loss in 35% of the participants.20 In the Hopkins POWER study, patients were randomized to behavioral weight loss interventions delivered remotely (by telephone) or in-person combined with a web-based weight loss tool. Initial behavioral interventions took place weekly for both groups. Weight decreased by 5% over 24 months in 38 and 41% of patients in the remote and in-person interventions, respectively.21 In a slightly less time-intensive and less costly approach, 20% of the participants in the POWER study conducted at Harvard achieved 5% weight loss with brief telephone contacts that initially occurred every month in combination with a web-based weight loss program.22 These LOSS and three POWER studies indicate that weight loss is not only achievable in the primary care setting before pregnancy, but there are several different and complimentary ways to accomplish weight loss goals.

Prenatal care

Often obese women have irregular periods or have suffered from infertility and might not recognize signs of pregnancy until later than their ideal-weight counterparts.23 Several retrospective studies and a recent systematic review found that obese women are at increased risk of miscarriage (odds ratio (OR) 1.3).24 Ideally, an ultrasound should be performed as early as possible to confirm dating and viability (see Figure 1). In addition to routine prenatal labs, super obese women should have a complete blood count, chemistry, liver function test, electrocardiography and 24 h urine protein ordered at their initial visit. An early rapid glucose screen should be performed and repeated between 24 and 28 weeks if normal. In addition, as Gunatilake et al.7 suggested, women with BMI 40 kg m−2 may benefit from an echocardiogram to evaluate for underlying, undiagnosed cardiomyopathy.7 In the second trimester, super obese women should be counseled on maternal and fetal risks and limitations of ultrasound, and appropriate consultations should be considered (see Figure 2).

Figure 1

Prenatal care. BMI, body mass index; EKG, electrocardiography. *If second trimester, see Figure 2.

Figure 2

Prenatal care. ^ Do not perform if the patient is a pregestational diabetic or if she is diagnosed with gestational diabetes after an early screen. * See Tables 3 and 4. Perform the rapid glucose screen between 24 and 28 weeks if an early screening test was negative or not performed. L&D, labor and delivery; OR, operating room.

Maternal risks

Obese women are at an increased risk of prepregnancy medical illnesses such as hypertension, diabetes, gallbladder disease, asthma and obstructive sleep apnea that have been associated with a twofold risk of stroke and underlying cardiac dysfunction.25 If underlying cardiopulmonary disease is suspected, the patient may benefit from a cardiology or pulmonology referral for additional testing such as an echocardiogram, sleep study or pulmonary function testing.

Obesity and pregnancy are independent risk factors for venous thromboembolism (VTE), and VTE is one of the leading causes of maternal death in the United States.26, 27 The risk of VTE appears to increase with increasing levels of obesity. A retrospective cohort study of over 142 000 pregnancies found women weighing 90 to 120 kg had a twofold increased risk of antepartum VTE as compared with women weighing <90 kg, and women weighing >120 kg had more than a threefold increased risk.28 Immobility in addition to obesity has been shown to significantly increase the risk of VTE among pregnant women.27, 29 Overweight and obese women (BMI >25 kg m−2) with a history of immobilization have an adjusted OR of 62.3 (95% confidence interval (CI) 11.5 to 337.6) for antenatal VTE and 40.1 (95% CI 8.0 to 201.5) for postnatal VTE as compared with women with a BMI of <25 kg m−2 and no immobilization.29 From these data, one can deduce that the risk of VTE among the super obese is confounded by immobility due to their weight. There are no randomized control trials or professional guidelines to assist with the decision to start prophylactic anticoagulation among these women during the antepartum or postpartum period. After a careful discussion of the risks and benefits, anticoagulation should be strongly considered and individualized.

The risk of hypertensive disorders in pregnancy among obese women is increased,3, 28 and the risk appears to have a linear relationship with BMI. In one prospective study of >16 000 pregnant patients in the United States, a BMI of 30 to 34.9 kg m−2 was associated with a 2.5 times increased risk of gestational hypertension as compared with ideal-weight controls, and a BMI of 35 kg m−2 was associated with a 3.2 times increased risk.3 We can only extrapolate what the risk might be among those with a BMI of 50 kg m−2. Similarly, the risk of gestational diabetes increases with rising maternal BMI, with obese women having a 2.6 times increased risk compared with ideal-weight controls and morbidly obese women having a fourfold increase in gestational diabetes.3

The risk of macrosomia has also been shown to increase with increasing BMI. In a large retrospective cohort study including >64 000 births, super obese women were significantly more likely to have macrosomic infants than their obese counterparts (adjusted relative risk (RR) of 1.8).4 In addition, they should also be counseled on their risk of cesarean section that approaches 50% for the morbid and super obese.3, 4

Fetal risks

The morbid and super obese pregnant woman should be counseled on their risk of fetal anomaly, particularly neural tube defects (NTDs). In a retrospective study including 292 open NTDs among 420 362 women, the adjusted OR for NTD was 1.2 per 10-kg incremental rise in maternal weight.30 In another series including 604 newborns, the relative risk of NTD was 3 to 4 for women weighing >100 kg.31 The effect was independent of estimated dietary folate intake, and there appeared to be no protective effect against NTD with recommended folate intake in obese women.31 Other birth defects associated with maternal obesity include craniofacial abnormalities and heart defects.32, 33 The above studies are limited when considering risk among fetuses of the morbid and super obese as most of them included women with BMI of 30 or 40 kg m−2 but did not quantify those with BMI 50 kg m−2.

Offspring to obese mothers are more likely to have low Apgar scores, and the risk of admission to the neonatal intensive care units is increased 3.5-fold.33, 34 Maternal obesity is associated with a more than doubled risk of stillbirth and neonatal death as compared with women of ideal weight.33, 35, 36 Again, further research is needed to determine whether these risks are substantiated and exaggerated in the fetuses of the super obese.

Ultrasound and prenatal diagnosis

Fetuses of obese women are at an increased risk for fetal anomalies compared with fetuses of normal-weight parturients, with the anomalies often involving the fetal cardiac or central nervous systems as described above. Targeted ultrasound by a maternal–fetal medicine specialist should be considered between 18 and 22 weeks. Further compounding the risk of fetal anomaly is the decreased sensitivity of antenatal ultrasound among women with high BMI because of the depth of insonation required and the absorption of ultrasound energy (dropout) by the abdominal adipose tissue.37, 38 Best et al.38 found that the odds of congenital anomaly detection were significantly decreased in obese women (adjusted OR, 0.77; 95% CI 0.60 to 0.99; P=0.046). To overcome these deficiencies, Paladini37 makes the following recommendations: lower transducer emission frequencies, use harmonic and compound imaging with speckle reduction filters, consider approaching fetus through the four major abdominal areas with least subcutaneous fat (periumbilical area, suprapubic area and right and left iliac fossae), consider using the transvaginal approach for assessment of the central nervous system in fetuses in vertex presentation, wait for the fetus to be in optimal position with a posterior spine and become familiar with the use of color Doppler to check cardiac inflows and outflows. In addition to these techniques, the provider should take into account the increased risk of congenital heart disease in women who are obese and the frustratingly low visualization rate. Providers should strongly consider a formal fetal echocardiography by a maternal–fetal medicine specialist or a pediatric cardiologist with expertise in fetal echoes.

Routine counseling should be modified to incorporate a discussion of the increased risk of anomalies and the reduced likelihood of detecting anomalies that may be present.39 The decreased ability to obtain an accurate nuchal translucency may limit the sensitivity of first-trimester screening.40 Patients should also be made aware that traditional serum screening for chromosomal abnormalities and open neural tube defects may not yield accurate results in super obese women, and diagnostic testing such as amniocentesis may be difficult to perform.41, 42 Ultrasound units should be prepared to allot more time for an obese patient’s scan and be aware that completion of anatomy may require multiple visits.

Given the inaccuracy of fundal height and increased risk of macrosomia3, 4 among the super obese, serial ultrasounds for fetal growth should be obtained every 3 to 4 weeks beginning at 24 weeks of gestation. In addition, consideration could be given to performing antenatal testing in the super obese gravida given the more than twofold risk of stillbirth.33, 35, 36

Gestational weight management

The super obese gravida should be counseled on weight management and appropriate weight gain encouraged throughout the pregnancy.43 In 2009, the Institute of Medicine (IOM) released updated guidelines on weight gain during pregnancy based on prepregnancy BMI.44 The IOM guidelines were developed to minimize negative health consequences for both mother and fetus of inadequate or excessive weight gain. The recommended total weight gain for obese women with BMI of 30 kg m−2 is 11–20 lb (5 to 9 kg). Recent studies have suggested that women who are in the morbid and super obese categories who gain weight below the IOM guidelines may have improved maternal and fetal outcome.45, 46, 47

Hinkle et al.45 evaluated weight gain during pregnancy and fetal growth among 122 327 obese pregnant women with a prepregnancy BMI of 30 kg m−2. Findings suggested weight gains that ranged from a loss of 4.9 kg to a gain of 4.9 kg among class II obese women (BMI 35 to 39.9 kg m−2), and class III (BMI 40 kg m−2) obese women did not significantly increase the odds of a small–for-gestational age and had the benefit of decreasing macrosomia. A population cohort study by Blomberg46 noted that obese women (class III) who lost weight during pregnancy had a decreased risk of cesarean delivery (OR 0.77, 95% CI 0.60 to 0.99), large-for-gestational-age births (OR 0.64, 95% CI 0.46 to 0.90) and no significantly increased risk for pre-eclampsia, excessive bleeding during delivery, instrumental delivery, low Apgar score or fetal distress compared with obese (class III) women gaining within the IOM recommendations. In this study, however, there was an increased risk for small for gestational age (OR 2.34, 95% CI 1.15 to 4.76) among women in obesity class III losing weight.46 These studies suggest that weight gain below the IOM guidelines may improve outcomes, but there is insufficient evidence to recommend weight loss for the super obese gravida.

Pregnancy offers a key opportunity for diet and lifestyle interventions, as women are often motivated to implement changes for their well-being as well as the well-being of their infant. There is currently limited information available on which to base clinical recommendations about effective dietary and lifestyle interventions for overweight and obese pregnant women. A recent Cochrane review evaluating interventions to prevent excessive gestational weight gain concluded that there is not enough evidence to recommend any one particular intervention.48 A meta-analysis by Thangaratinam et al.,49 which included 44 randomized control trials, evaluated diet, exercise or a combination approach (diet and exercise) among pregnant women and demonstrated that dietary and lifestyle interventions in pregnancy are effective in reducing gestational weight gain without any adverse effect on fetal outcomes. The authors noted that the largest reduction in weight gain was among the diet-only intervention women (3.84 kg, 2.45 to 5.22 kg; P<0.001), and the diet-only intervention was noted to significantly reduce the risk of pre-eclampsia (RR 0.63, 95% CI 0.42 to 0.96), gestational diabetes (RR 0.39, 95% CI 0.23 to 0.69) and gestational hypertension (RR 0.30, 95% CI 0.10 to 0.88) among overweight and obese pregnant women. With all interventions combined, there was no significant difference in low birth weight or small-for-gestational-age infants.49 Their findings suggested that perhaps interventions focused on diet might be most effective. The focus during pregnancy for overweight and obese women should be on avoiding excessive gestational weight gain and implementation of dietary and lifestyle changes that can be continued past the postpartum period.43, 50, 51 Interventions should include a balanced diet, physical activity, nutritional counseling and continued reinforcement by obstetric provider throughout the pregnancy.43, 50, 51 Further research is needed among overweight and obese pregnant women to identify the optimal intervention to minimize maternal and fetal complications.

Please see Table 2 for a prenatal care checklist for super obese women.

Table 2 Prenatal checklist for super obese women

Inpatient management

A multidisciplinary team, including maternal–fetal medicine, anesthesia, nursing, pharmacy, nutrition, physical therapy, cardiology and pulmonology should be established for inpatient management of the super obese gravida. Difficult intravenous access is commonly encountered among super obese women and placement of peripherally inserted central catheter should be considered. If the patient is not anticoagulated, risks and benefits of inpatient anticoagulation should be addressed after admission.

Transportation and hospital equipment

In addition to a medical workup, plans should be made to ensure your facility can accommodate the super obese patient. These patients often have limited capability for transportation to and from the hospital, greatly compromising their need for prompt arrival in case of emergency. In such cases, hospitalization should be considered. Very often, these patients exceed weight limits for standard ambulances and specialized transportation may be needed.

Additional things to consider include elevators, wheelchairs, beds, doorways, lifting equipment, bathrooms and operating room equipment (Table 3). A 6000- to 6500-lb capacity elevator is needed to provide sufficient space for a 40-inch-wide, 90-inch long bed as many of these patients are transported in their beds.52 Elevators of this size can hold the obese patient, bed, equipment and two staff members.52 Bariatric wheelchairs are sized by weight-limit categories. The largest models can have seat widths of up to 48 inches and require a 6-foot or larger turning radius.52 With regard to hospital beds, primary consideration should be on maximum weight accommodation, with bariatric beds ranging from 600- to 1000-lb weight capacity.52, 53 Many bariatric beds come with pressure redistribution air surfaces that automatically adjust to patient’s weight, body type and movement to help prevent pressure ulcers. Most standard labor beds accommodate up to 500 lb.53 Special arrangements need to be made if a vaginal delivery is planned for a patient weighing >500 lb. Ideally, doorways should be over 3 feet wide.52 Lifting equipment is essential to avoid staff and patient injuries. Bariatric lifts can cost anywhere from $2000 to $6000.52 Portable or ceiling mounted patient lift systems are acceptable.52 The toilet should be placed toward the center of the wall to allow room on each side of the commode for assistants.52 Toilets should be anchored to the floor, not the wall. The most common solution on the market today is floor-mounted stainless steel toilets with a capacity of 5000 lb.52 Bathroom walls should have extra strength blocking to support grab bars, as well as sinks that are capable of supporting the extra weight.

Table 3 Hospital equipment for the super obese

Mode of delivery

The cesarean section rate approaches 50% for the morbid and super obese.3, 4 Failure to progress and failed trial of labor after cesarean section is more common among these women.54, 55 Elective primary cesarean sections are also increased. In one study, 33.8% of nulliparous super obese women underwent a scheduled primary cesarean delivery.4 The indication for these primary cesarean deliveries is not stated, but may be obesity itself. Often in the super obese gravida, a large pannus and severe lower extremity lymphedema limits range of motion and access to the perineum, making safe vaginal delivery essentially impossible. Continuous fetal monitoring and performing a STAT cesarean section may be limited or even impossible because of the body habitus of the super obese gravida. A frank discussion of some of the clinical limitations should be reviewed with the patient. The mode and timing of delivery should be individualized, weighing the risks to the fetus and mother.

Intraoperative preparation

Preparation for surgery in the extremely obese patient should include many of the same guidelines as for ideal body weight patients. However, additional or special equipment is necessary to facilitate a safe delivery. A standard surgical table accommodates 350 to 500 lb and therefore a special bariatric surgical table with a weight capacity of 600 to 1000 lb is necessary.53 Many of the bariatric tables include extensions for greater width if necessary.53 Other intraoperative equipment to have readily available includes extra large sequential compression devices, large safety belts, retractors for subcutaneous fat such as the Alexis O C-section retractor or more traditional retractors deep retractors (Table 4).

Table 4 Operating room equipment for the super obese

Anesthesia considerations

The American College of Obstetricians and Gynecologists (ACOG) recommends early referral for anesthesia consultation in the management of obesity in pregnancy.5 Ideally, a consultation should be scheduled before the time of delivery to assess if additional testing is warranted such as pulmonary function tests, echocardiogram or sleep apnea studies. Because of obscured anatomic landmarks, increased skin to epidural space depth and a more narrow epidural space in super obese patients, regional anesthesia can be very difficult and occasionally unattainable.56 Preoperatively, the anesthesiologist can perform a physical exam and should assess if regional anesthesia is feasible. The anesthesiologist may use ultrasound to help determine the length of epidural or spinal needle required.57 It should also be noted that one of the reasons for the failure of an epidural catheter to provide adequate block has been the greater risk of catheter dislodgement in the obese parturient.56, 57 Care should be taken to avoid dislodgement during patient transfer or change of positions. Secondary to increased risks of general anesthesia, a functioning epidural should ideally be attempted in women during early labor or before scheduled cesarean delivery. The risk of failed epidural is increased, with 75% of morbidly obese gravidas requiring more than one attempt and 14% requiring over three attempts for successful epidural placement.56, 58

If general anesthesia cannot be avoided, the obstetrician and anesthesiologist should be aware of the increased risk of difficult or failed tracheal intubation in obese pregnant women. Difficult intubation rates in obese pregnant women have been reported to be as high as 33%,57 and this is likely increased further in the super obese. Fat deposition in the neck, back and airway often precludes optimal positioning of the laryngoscope, and underlying respiratory disorders and weight of the chest wall decreases residual lung volume and functional residual capacity.57, 58 Furthermore, excess body weight increases oxygen consumption and CO2 production.56 All of these physiologic changes in the obese patients make them more susceptible to rapid desaturation during intubation.57 In anticipation of a difficult airway, good preoxygenation should always be performed, and an extra pair of skilled hands and emergent airway supplies should be readily available. To facilitate laryngoscopy, the patient should be placed in a ‘ramped’ position with blankets under the patient’s thorax and head.56

Antibiotic dosing

Skin cleansing before surgery to reduce bacterial colonization can be done before surgery, followed by povidine-iodine or chlorohexidine preparation covering the entire surgical site in the operating room. In addition, antibiotic prophylaxis is necessary to reduce risk of postoperative infection. The pharmacokinetics of antibiotic dosing in patients with super obesity is complicated and there are few studies on this topic. Dosing is drug specific because of differences in plasma proteins, drug lipophilicity and variations in blood flow to adipose tissue.59 Because of the relative unpredictability of pharmacokinetics in obese individuals, doses are best estimated on the basis of specific studies for individual drugs carried out on this population. The antibiotic of choice for cesarean delivery is cefazolin as it is effective against Gram-positive and -negative bacteria. In a study analyzing serum and adipose tissue levels of cefazolin given to morbidly obese patients, only when 2 g of cefazolin were administered (versus 1 g) were levels adequate for surgical prophylaxis.60 A more recent study evaluated serum concentrations of cefazolin in three groups: BMI of 40 to 49, 50 to 59 and >60 kg m−2. All three groups received 2 g of cefazolin. In all, 41% of patients with BMI of 40 to 49 kg m−2 and 18% of those with BMI of 50 to 59 kg m−2 had serum concentrations that were at the therapeutic threshold 3 h after skin incision, whereas there were no samples from the BMI >60 kg m−2 group at the therapeutic level. Based on these limited studies, it has been suggested that at least 2 g rather than the standard 1 g be used in women with BMI of >35 kg m−2.61

Consideration has been given to increasing the cefazolin dose to 3 g for super obese patients. Ho et al.59 calculated serum cefazolin concentrations at 30, 120 and 360 min after administration of either 2 or 3 g in morbid (BMI 40 to 50 kg m−2) and super obese (BMI >50 kg m−2) patients. They found levels above the minimum inhibitory concentration necessary for elective surgical prophylaxis (8 μg ml−1) in both patient BMI groups receiving 2 and 3 g doses.59 Although a 3 g dose of cefazolin is safe for patients with a BMI >50 kg m−2, their data suggest that a 2 g dose provides sufficient exposure.59 Although these studies address women with BMI of >50 kg m−2, there are no studies addressing patients with BMIs approaching 100 kg m−2. After consultation with our obstetric clinical pharmacist, the decision was made to give 3 g of cefazolin with plan for a repeat dose if operating time was >3 h or estimated blood loss was >1500 ml.

Skin incision

The ideal surgical skin incision (transverse or vertical) in obese pregnant women is controversial. The advantages to a transverse incision include increase wound strength, decreased postoperative pain and improved postoperative respiratory effort,7 however, the concern is for increased infection if placed under a large pannus. The advantages to a vertical incision include better surgical access and better visualization by the patient for postoperative care. However, this incision is more painful, has decreased strength with increase likelihood of dehiscence and herniation and is more likely to require vertical hysterotomy.7, 62 There are currently no randomized control trials comparing the two incision types in morbidly or super obese parturients. When deciding on an incision type, the surgeon needs to assess the anatomy closely, including location of symphysis pubis, iliac wings and uterine fundus. In our case we opted for a supraumbilical vertical incision as the patient adamantly desired the ability to visualize the incision in order to care for it without assistance at home. In addition, given the size of her pannus, we felt that despite maximum traction we would not be able to adequately retract to safely perform a low transverse incision.

Perioperative anticoagulation

As previously discussed, obesity and cesarean delivery are both risk factors for VTE. There is currently no clear evidence regarding the type of VTE prophylaxis that should be given in obese pregnant women undergoing cesarean delivery. The Royal College of Obstetricians and Gynaecologists (RCOG) in the United Kingdom suggests consideration of thromboprophylaxis for 7 days with low-molecular-weight heparin following a normal vaginal delivery for those with BMI >40 kg m−2 and for those delivered by cesarean with BMI >30 kg m−2.63 In the United States, the Pregnancy and Thrombosis Working Group did not concur with these exact guidelines and instead suggest considering thromboprophylaxis for patients who are obese, on bed rest or having surgery.64 Morbid and super obesity were not specifically addressed. At the very least, early ambulation should be encouraged and mechanical prophylaxis with pneumatic compression stockings should be used peri- and intra-operatively for all patients. Consideration regarding pharmacologic thromboprophylaxis should be individualized, and among patients with super obesity who have limited mobility, thromboprophylaxis should be strongly encouraged.


Contraception should be addressed with every woman of reproductive age, but especially with those who pose significant pregnancy risks such as the morbid and super obese. There are limited studies including women with BMIs 35 kg m−2, and no safety information exists regarding contraception for women specifically with BMIs 50 kg m−2. Obesity itself is a significant risk factor for VTE, which increases in obese women using contraceptive methods containing estrogen.65 There have been studies estimating that obese women using oral contraceptives have a 24-fold higher thrombotic risk compared with normal BMI women without use.65 In accordance with Centers for Disease Control and Prevention Medical Eligibility Criteria for Contraceptive Use, all methods of contraception are risk category 1 (no restriction for use) except for combined hormonal methods that are assigned category 2 (advantages of use generally outweigh risks) in healthy obese women with no cardiovascular risk factors.66 Category 2 was assigned because of the small absolute increased risk of women with BMI 30 kg m−2 to experience VTE while using combined hormonal contraceptives.66 Risks to women with BMI of 50 kg m−2 are not specifically addressed.

The American College of Obstetrics and Gynecology (ACOG) recommends long-acting reversible contraceptive methods, including intrauterine devices (IUDs) and the contraceptive implant, be offered to most women as the first-line contraceptive method.67 This recommendation includes obese women. Although women >30% above ideal body weight were excluded from most investigations, a recent study found that 3-year failure rates for the implant and IUDs were less than one per 100 women-years.68 Because of the high cesarean section rate among obese patients and potential for difficult office insertion of such devices, strong consideration should be given to intraoperative placement of IUDs. There have been several recent studies examining immediate postplacental insertion of IUDs at the time of cesarean section, and the results show a slightly increased rate of expulsion and lack of visualization of the strings at follow-up, but overall the conclusions are in agreement that this technique is safe and acceptable.69, 70


The prevalence of super obesity is increasing and nearly all pregnancy complications occur in this population at greater frequency. Providers should be competent in counseling super obese parturients on maternal risks, fetal risks and weight management while keeping in mind the limitations of our current knowledge and ultrasound technology. Preparing for delivery should begin early in order to procure adequate equipment to ensure safety for the patient and staff. A multidisciplinary team should be recruited for management of the super obese. Contraception should be addressed with all extremely obese women and long-acting reversible contraceptive methods should be offered as first line with consideration for IUD placement at the time of delivery. In light of current trends, obstetricians should anticipate seeing increasing numbers of super obese gravidas. Ongoing research will be critical in mitigating the increased risks highlighted in this review.


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We thank Emory University Department of Gynecology and Obstetrics, Atlanta, GA, USA.

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Martin, A., Krishna, I., Ellis, J. et al. Super obesity in pregnancy: difficulties in clinical management. J Perinatol 34, 495–502 (2014).

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  • complications
  • morbid obesity
  • obesity
  • pregnancy
  • super obesity

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