Williams Obstetrics, 24th Edition

CHAPTER 48. Obesity

GENERAL CONSIDERATIONS

MORBIDITY AND MORTALITY ASSOCIATED WITH OBESITY

TREATMENT OF OBESITY

PREGNANCY AND OBESITY

Excessive weight is a major health problem in the United States and other affluent societies. For a number of years, obesity was said to be epidemic—strictly defined, this implies a temporary widespread outbreak of greatly increased frequency and severity. Unfortunately, obesity more correctly is endemic—a condition that is habitually present. By 1991, approximately a third of adults in the United States were overweight, and thus a stated goal of Healthy People 2000 was to reduce the prevalence of overweight people to 20 percent or less by the end of the 20th century (Public Health Service, 1990). Not only was this goal not achieved, but by 2000, more than half of the population was overweight. In 2010, a third of all adults were obese (Ogden, 2012).

The adverse health aspects of obesity are staggering. Obesity-related diseases include diabetes, heart disease, hypertension, stroke, and osteoarthritis. Obese women who become pregnant—and their fetuses—are predisposed to various serious pregnancy-related complications. Moreover, long-term maternal and fetal effects include significant and increased morbidity and mortality rates.

GENERAL CONSIDERATIONS

image Definitions

A number of systems have been used to define and classify obesity. The body mass index (BMI), also known as the Quetelet index, is currently most often used. The BMI is calculated as weight in kilograms divided by the square of the height in meters (kg/m2). Calculated BMI values are available in various chart and graphic forms, such as the one shown in Figure 48-1. The National Institutes of Health (2000) classifies adults according to BMI as follows: normal (18.5 to 24.9 kg/m2); overweight (25 to 29.9 kg/m2); and obese (≥ 30 kg/m2). Obesity is further divided into: class 1 (30 to 34.9 kg/m2); class 2 (35 to 39.9 kg/m2); and class 3 (≥ 40 kg/m2).

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FIGURE 48-1 Chart for estimating body mass index (BMI). To find the BMI category for a particular subject, locate the point at which the height and weight intersect.

image Prevalence

By 2000, 28 percent of men and 33 percent of women were obese (Ogden, 2012). For the period 2009 to 2010, among men and women these percentages were almost identical at approximately 35 percent. Shown in Figure 48-2 are the prevalences of obesity among girls and women. Obesity increases with age as well as with ethnic minority, and almost 60 percent of black women were obese in 2010. This is also true among indigent individuals (Drewnowski, 2004).

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FIGURE 48-2 Prevalence of obesity in girls and women in the United States for 2009–2010. (Data from Flegal, 2012; Ogden, 2012.)

image Adipose Tissue as an Organ System

Fat tissue is much more complex than its energy storage function. Many cell types in fat tissue communicate with all other tissues via endocrine and paracrine factors—adipokines, or adipocytokines. Some of those with metabolic functions include adiponectin, leptin, tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), resistin, visfatin, apelin, vascular endothelium growth factor (VEGF), lipoprotein lipase, and insulin-like growth factor (Briana, 2009; Scherer, 2006). A principal adipokine is adiponectin, which is a 30-kDa protein. It enhances insulin sensitivity, blocks hepatic release of glucose, and has cardioprotective effects on circulating plasma lipids. An adiponectin deficit leads to diabetes, hypertension, endothelial cell activation, and cardiovascular disease.

Adipocytokines in Pregnancy

Cytokines that result in insulin resistance—leptin, resistin, TNF-α, and IL-6—are increased during pregnancy. Indeed, these may be the primary stimulant of insulin resistance. Secretion of the remaining adipokines is either unchanged or decreased. Specific patterns have been variously described with gestational diabetes, preeclampsia, and fetal-growth restriction (Briana, 2009). In a longitudinal study of 55 pregnant women, Meyer and associates (2013) confirmed that higher BMIs are associated with lower adiponectin but higher leptin levels.

image Metabolic Syndrome

Given its multifaceted endocrine and paracrine functions, it is not surprising that excessive fat tissue is detrimental (Cornier, 2011). One major drawback is that obesity interacts with inherited factors to cause insulin resistance and in some cases, the metabolic syndrome. This resistance is characterized by impaired glucose metabolism and a predisposition to type 2 diabetes. Insulin resistance also causes several subclinical abnormalities that predispose to cardiovascular disease and accelerate its onset. The most important among these are type 2 diabetes, dyslipidemia, and hypertension, which define the metabolic syndrome.

Criteria used by the National Institutes of Health (2001) to define the metabolic syndrome are shown in Table 48-1. Virtually all obese women with hypertension demonstrate elevated plasma insulin levels. These are even higher in women with excessive fat in the abdomen—an apple shape—compared with those whose fat is in the hips and thighs—a pear shape (American College of Obstetricians and Gynecologists, 2003).

TABLE 48-1. Criteria for Diagnosis of the Metabolic Syndrome


Patients with three or more of the following:

Waist circumference: > 88 cm (34.7 in) in women; > 102 cm (40.2 in) in men

Hypertriglyceridemia: ≥ 150 mg/dL

High-density lipoprotein (HDL): < 50 mg/dL in women; < 40 mg/dL in men

High blood pressure: ≥ 130/85 mm Hga

High fasting glucose: ≥ 110 mg/dLa

aThose with normal values while taking medications are considered to meet these criteria.

From National Institutes of Health, 2001.

Prevalence

Ford and colleagues (2002) did a follow-up study of men and women enrolled in the Third National Health and Nutrition Survey (NHANES III). They found an overall prevalence of the metabolic syndrome in 24 percent of women and 22 percent of men. As expected, prevalence increased with age. For women, prevalence was approximately 6 percent in those 20 to 29 years; 14 percent in those 30 to 39 years; 20 percent in those 40 to 49 years; and 30 percent for women older than 50 years. Jordan and colleagues (2012) reported similar figures in adults in New York City in 2004.

image Nonalcoholic Fatty Liver Disease (NAFLD)

Generally speaking, visceral adiposity correlates with hepatic fat content (Cornier, 2011). With obesity, excessive fat accumulates in the liver—hepatic steatosis. Specifically, in persons with the metabolic syndrome, steatosis can progress to nonalcoholic steatohepatitis (NASH) and cirrhosis. Indeed, a fourth of cases of chronic liver disease in Western countries are caused by nonalcoholic fatty liver disease (NAFLD) (Targher, 2010). Moreover, NAFLD either is a marker for cardiovascular disease or is involved in its pathogenesis. This may be related to an inherited prothrombotic state (Verrijken, 2014).

Pregnancy

Experience with NAFLD in pregnancy is limited (Page, 2011). It also appears that the increased insulin resistance it imposes causes excess gestational diabetes (Forbes, 2011). In addition, insulin resistance mobilizes free fatty acids to increase their plasma levels. In nonpregnant adults, hepatic fat content normally is 1 to 5 percent of liver mass, however, this has not been studied in pregnant women (Browning, 2004). However, Meyer and associates (2013) found that overweight and obese gravidas had a higher proportion of low-density lipoprotein III (LDL-III) compared with that of normal-weight women. LDL-III predominance is a hallmark of ectopic liver fat accumulation that is typical of NAFLD. At Parkland Hospital, with increasing frequency we are encountering obese women who have NAFLD with evidence of steatohepatitis manifest by elevated serum hepatic aminotransferase levels. In some cases, liver biopsy is necessary to exclude other causes.

MORBIDITY AND MORTALITY ASSOCIATED WITH OBESITY

Obese individuals are at increased risk for an imposing number of complications (Table 48-2). The direct link between obesity and type 2 diabetes mellitus is well known. Ninety percent of type 2 diabetes cases are attributable to excess weight, and 75 percent of these diabetics have the metabolic syndrome (Hossain, 2007). Heart disease due to obesity—adipositas cordis—is caused by hypertension, hypervolemia, and dyslipidemia. Higher rates of abnormal left ventricular function, heart failure, myocardial infarction, and stroke have been noted (Chinali, 2004; Kenchaiah, 2002; Targher, 2010).

TABLE 48-2. Long-Term Complications of Obesity

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Excessive weight is associated with increased rates of early mortality, as shown by Peeters (2003) and Fontaine (2003) and their colleagues in follow-up studies from both the Framingham Heart Study and the NHANES III cohort. Mortality results from pooled data from 19 prospective studies are shown in Figure 48-3. In these and other studies, mortality risk from cardiovascular disease and cancer increased directly with increasing BMI.

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FIGURE 48-3 Estimated hazard ratios (95% CI) for death due to cardiovascular disease according to body mass index among 1.46 million white adult men and women. (Data from de Gonzalez, 2010.)

TREATMENT OF OBESITY

Weight loss is tremendously difficult for obese individuals. If achieved, long-term maintenance poses equivalent or even more daunting difficulties. Even the most legitimate nonsurgical methods are fraught with frequent failure. If they are successful, slow and inexorable return to preintervention weight usually follows (Yanovski, 2005). Successful weight loss approaches include behavioral, pharmacological, and surgical techniques or a combination of these methods (Eckel, 2008; Zimmet, 2012). As such, obstetrician-gynecologists are encouraged to aid assessment and management of obesity in adult women. Weight loss and lifestyle changes have been shown to reduce the associated metabolic syndrome (Crist, 2012). When used in conjunction with bariatric surgery, there is improved glucose control with type 2 diabetes (Mingrone, 2012; Schauer, 2012).

PREGNANCY AND OBESITY

Obese women unequivocally have reproductive disadvantages. This translates into difficulty in achieving pregnancy, early and recurrent pregnancy loss, preterm delivery, and a myriad increased obstetrical, medical, and surgical complications with pregnancy, labor, delivery, and the puerperium (American College of Obstetricians and Gynecologists, 2013a). Obesity in pregnancy is also associated with increased health-care utilization and costs (Pauli, 2013). Finally, infants—and later, adults—of obese mothers have correspondingly increased rates of morbidity, mortality, and obesity (Reynolds, 2013).

Obesity results in subfertility due to increased insulin resistance as in polycystic ovarian syndrome. Leptin dysregulation also results in loss of gonadotropin secretory rhythms (Maguire, 2012). Impaired fecundity has been linked to women with a BMI > 30 kg/m2 (Neill, 2001). In 6500 in vitro fertilization-intracytoplasmic sperm injection cycles, Bellver and associates (2010) found that implantation, pregnancy, and livebirth rates were progressively and significantly reduced with each unit of maternal BMI. As discussed in Chapter 8 (p. 157), obesity is associated with increased risk of first-trimester and recurrent miscarriage (Lashen, 2004; Metwally, 2008). In the many overweight and obese women who achieve pregnancy, there is a litany of increased and interrelated adverse perinatal outcomes that are discussed subsequently.

image Prevalence

As expected from reviewing Figure 48-2, obesity complicating pregnancy has increased substantially in this country. Before adoption of the BMI, investigators used various definitions of obesity to assess risks during pregnancy. For example, in an earlier study from the University of Alabama at Birmingham, four definitions were used, but regardless of how obesity was defined, all groups showed at least twofold increases in prevalence during the 20-year period (Lu, 2001). Equivalent findings were reported from a 15-year study done in Cleveland (Ehrenberg, 2002). Our experience at Parkland Hospital is similar, as shown in the three epochs depicted in Figure 48-4.

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FIGURE 48-4 Increasing prevalence of obesity during three epochs in pregnant women classified at the time of their first prenatal visit at Parkland Hospital. (Data courtesy of Dr. Don McIntire.)

image Maternal Weight Gain and Energy Requirement

The Institute of Medicine (2009) updated its previous comprehensive reviews of maternal weight gain determinants in relation to biological, metabolic, and social predictors. Its recommended weight gains for various BMI categories are shown in Table 9-5 (p. 177). For overweight women, weight gain of 15 to 25 pounds is recommended. For obese women, the Institute recommends a gain of 11 to 20 pounds. This is because fat deposition is greater in women with high BMIs, and thus, energy costs are significantly lower (Butte, 2004). Kinoshita and Itoh (2006) found that during the third trimester, increases were predominantly in visceral fat. Despite these stores, maternal catabolism is—at least intuitively—not good for fetal growth and development. The American College of Obstetricians and Gynecologists (2013c) has endorsed these Institute guidelines.

These Institute guidelines for obese women have some, although minimal, foundation in scientific evidence (Rasmussen, 2010). In a study of 2080 obese women, there was no advantage to weight gain > 20 pounds (Vesco, 2011). However, Chu and coworkers (2009) reported in the United States in 2004 to 2005 that 40 percent of normal-weight and 60 percent of overweight women gained excessive weight during pregnancy. The Maternal-Fetal Medicine Units Network arrived at similar conclusions. Seventy-five percent of nearly 8300 nulliparas gained more weight than the Institute recommendations (Johnson, 2013). Additionally, women who gained more than the recommended amount had excessive postpartum weight gain at 3, 8, and 15 years after delivery (Nehring, 2011; Rooney, 2002).

image Maternal Morbidity

Some of the excess perinatal morbidity due to obesity is listed in Table 48-3. In studies, various definitions of obesity in pregnant women have included 150 percent of ideal body weight, BMI > 35 kg/m2, BMI > 40 kg/m2, BMI > 50 kg/m2, and > 150 pounds over ideal body weight (Cedergren, 2004; Crane, 2013; Denison, 2008; Kabiru, 2004; Kumari, 2001; Stamilio, 2013). In one study, Weiss and colleagues (2004) reported similar adverse outcomes and maternal morbidity in a prospective multicenter study of more than 16,000 women from the FASTER trial (First- and Second-Trimester Evaluation of Risk). As shown in Figures 48-5 and 48-6, especially striking are the marked increases in gestational diabetes and hypertension. Lipkind and associates (2013) showed obesity to be an independent risk factor for “near-miss” maternal morbidity (Chap. 1p. 6).

TABLE 48-3. Adverse Pregnancy Effects in Overweight and Obese Women

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FIGURE 48-5 Incidence of selected pregnancy outcomes in 16,102 women enrolled in the FASTER (First- and Second-Trimester Evaluation of Risk) trial according to body mass index (BMI) status. (Data from Weiss, 2004.)

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FIGURE 48-6 Frequency of preeclampsia according to body mass index. (Data from the Hyperglycemia and Adverse Pregnancy Outcome [HAPO] Study Cooperative Research Group, 2010.)

Not shown in Figure 48-5 are the cesarean delivery rates. These were 33.8 percent for obese and 47.4 percent for morbidly obese women compared with only 20.7 percent for the normal-weight control group (Weiss, 2004). Similar results were subsequently described by Garabedian and coworkers (2011). Haeri and colleagues (2009) also found increased rates of cesarean delivery and gestational diabetes in obese adolescents. More worrisome is that obese women also have increased rates of emergency cesarean delivery (Lynch, 2008; Poobalan, 2009). Finally, wound infections are more common. Alanis and associates (2010) reported this complication in 30 percent in women whose BMI was > 50 kg/m2.

There are also reports of increased adverse pregnancy outcomes in overweight women whose BMI is 25 to 29.9 kg/m2 (Hall, 2005). Shown in Table 48-3 were results of two studies that included more than 285,000 singleton pregnancies. Although not as magnified as in the obese cohort, almost all complications are significantly increased in overweight women compared with those whose BMI is normal.

Obesity is detrimental to the accuracy of obstetrical ultrasound examination (Weichert, 2011). Other morbidity includes a higher incidence of failed trial of labor with a prior cesarean delivery (Bujold, 2005; Goodall, 2005; Hibbard, 2006; Robinson, 2005). Obesity and hypertension are common cofactors in causing peripartum heart failure (Cunningham, 1986, 2012). And, obese women present anesthesia challenges that include difficult epidural and spinal analgesia placement and complications from failed or difficult intubations (Hood, 1993; Mace, 2011). Second-trimester dilatation and evacuation was reported to take longer and be more difficult in women whose BMI was 30 kg/m2 or greater (Dark, 2002).

Obese women are less likely to breast feed than normal-weight women (Li, 2003). They also have greater weight retention 1 year after delivery (Catalano, 2007; National Research Council and Institute of Medicine, 2007; Rode, 2005). Finally, there is evidence that quality-of-life measures are negatively affected by obesity during pregnancy (Amador, 2008). LaCoursiere and Varner (2009) found that postpartum depression was significantly increased in obese women in relation to the degree of obesity—class 1, 23 percent; class 2, 32 percent; and class 3, 40 percent.

Gestational Diabetes

Obesity and gestational diabetes are inextricably linked. Their coexistence with and adverse effects on pregnancy outcomes are discussed in Chapter 57 (p. 1139).

Preeclampsia

There is no doubt that obesity is a consistent risk factor for preeclampsia (see Fig. 48-6). In a review of studies that included more than 1.4 million women, O’Brien and associates (2003) found that the preeclampsia risk doubled with each 5 to 7 kg/m2 increase in prepregnancy BMI. In The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study (2010), the incidence of preeclampsia increased almost geometrically with each BMI category. Obesity and the metabolic syndrome discussed on page 962 are characterized by insulin resistance causing low-grade inflammation and endothelial activation (Catalano, 2010). These have a central and integral role in development of preeclampsia as discussed in Chapter 40 (p. 733). Wolf and colleagues (2001) linked these two conditions, and Ramsay and coworkers (2002) confirmed that obese pregnant women had significantly elevated serum levels of IL-6 and C-reactive protein and impaired endothelial function. Obese gravidas were found to have significantly higher levels of triglycerides, very-low-density lipoprotein cholesterol, insulin, and leptin compared with normal-weight pregnant woman.

Contraception

Most studies report that oral contraceptive failure is more likely in overweight women. This is discussed in detail in Chapter 38 (p. 695).

image Perinatal Mortality

Stillbirths are more prevalent as the degree of obesity increases (see Table 48-3). Indeed, in a review of almost 100 population-based studies, Flenady and associates (2011) found that obesity was the highest ranking modifiable risk factor for stillbirth. Chronic hypertension with superimposed preeclampsia associated with obesity is one cause of excessive stillbirths. An increased incidence of otherwise inexplicable late-pregnancy stillbirths and early neonatal deaths is also associated with obesity (Cnattingius, 1998; Stephansson, 2001; Waldenström, 2014; Yao, 2014). In one metaanalysis, there was a 1.5-fold increased risk for stillbirth in overweight and a 2.1-fold risk in obese women (Chu, 2007). A Scottish study of more than 186,000 nulliparas described an almost fourfold increased stillbirth rate in women with a BMI ≥ 35 kg/m2 compared with women of normal size (Denison, 2008). Increased prepregnancy weight was the factor most strongly associated with unexplained fetal deaths even after adjusting for maternal age and excluding women with diabetes and hypertensive disorders (Huang, 2000; Nohr, 2005; Ovesen, 2011).

image Perinatal Morbidity

Both fetal and neonatal complications are increased in obese women. The Atlantic Birth Defects Risk Factor Surveillance Study found a two- to threefold increased incidence in various anomalies in obese women (Watkins, 2003). Rasmussen and coworkers (2008) performed a metaanalysis and found 1.2-, 1.7-, and 3.1-fold increased risks for neural-tube defects in overweight, obese, and severely obese women, respectively. Another metaanalysis found that maternal obesity was significantly associated with an increased risk of a wide range of anomalies (Stothard, 2009). The National Birth Defect Prevention Study reported a correlation between BMI and congenital heart defects (Gilboa, 2010). According to Biggio and colleagues (2010), however, this may be related to diabetes as a cofactor. Already mentioned is concern for unreliable fetal anatomy sonographic screening in obese women (Dashe, 2009; Thornburg, 2009; Weichert, 2011).

Two important and interrelated cofactors that contribute to excessive rates of perinatal morbidity are chronic hypertension and diabetes mellitus, both of which are associated with obesity. Affected women have increased rates of preterm delivery and fetal-growth restriction (McDonald, 2010; Waldenström, 2014; Wang, 2011). As discussed above, pregestational diabetes increases the birth defect rate, and gestational diabetes is complicated by excessive numbers of large-for-gestational age and macrosomic fetuses (Chap. 44p. 884).

Even without diabetes, the prevalence of macrosomic newborns is increased in obese women (Cedergren, 2004; Ovesen, 2011). The group from MetroHealth Medical Center in Cleveland has conducted studies of prepregnancy obesity, gestational weight gain, and prepregnancy and gestational diabetes and their relationship to newborn weight and fat mass (Catalano, 2005, 2007; Ehrenberg, 2004; Sewell, 2006). Although each of these variables was found to be associated with larger and more corpulent newborns, prepregnancy BMI had the strongest influence on the prevalence of macrosomic neonates. They attributed this increased prevalence of macrosomic infants to the marked frequency of overweight or obese women in pregnancy—47 percent—rather than the 4 percent of pregnant women with diabetes. More recently, Edlow and associates (2013) have shown that genes expressed in the adult metabolic syndrome may be initiated in the fetus.

Morbidity in Children Born to Obese Women

It appears that obese women beget obese children, who themselves become obese adults. Whitaker (2004) studied low-income children in the Special Supplemental Food Program for Women, Infants, and Children (WIC) and found a linear association between early pregnancy maternal BMI and prevalence of overweight children at 2, 3, and 4 years. Schack-Nielson and associates (2005) reported a direct association between maternal, newborn, and childhood BMI. This association strengthened as offspring progressed to adulthood. Catalano and coworkers (2005) studied offspring at a median age of 7 years and found a direct association with maternal prepregnancy obesity and childhood obesity. They also reported associations with central obesity, elevated systolic blood pressure, increased insulin resistance, and decreased high-density lipoprotein (HDL) cholesterol levels—all elements of the metabolic syndrome. In their analysis of 28,540 women, Reynolds and associates (2013) found increased rates of cardiovascular disease and all-cause mortality in offspring of overweight and obese mothers. Boney and colleagues (2005) studied offspring of women with or without gestational diabetes. They observed that children who were large for gestational age at birth and whose mothers were either obese or had gestational diabetes had significantly increased risks for developing metabolic syndrome.

It also appears that excessive maternal weight gain in pregnancy may predict adulthood obesity in their offspring. Schack-Nielsen and associates (2005) found a linear association of maternal weight gain with the subsequent BMI in their children. Analyzing data from Project Viva, Oken (2006) confirmed this. However, not all studies concur. In their analysis of children in the WIC program cited above, Whitaker and associates (2004) found no obvious linear association between gestational weight gain and childhood obesity. This is also discussed in some detail in Chapter 44 (p. 876).

Fetal Programming and Childhood Morbidity

Epidemiological studies have addressed the association of childhood, adolescent, and even adult adverse health outcomes in relation to the fetal environment. Adverse outcomes include obesity, diabetes, hypertension, and the metabolic syndrome. Variables studied have included maternal prepregnancy BMI, obesity, gestational weight gain, and pregestational or gestational diabetes. The most robust evidence suggests a direct association between children born to women who had prepregnancy obesity or gestational diabetes and being overweight in childhood and adulthood.

The potential biological causes and mechanisms of these associations are not clear. Elucidation is limited by insufficient data on potential maternal and genetic predisposing factors and on the environment of the infant and child in relation to diet and activity. The science of epigenetics has provided some support for the possibility that perturbations of the maternal-fetal environment can adversely alter postdelivery events (Aagard-Tillery, 2006). Perhaps more likely are contributions of the maternal-child environment subsequent to birth (Gluck, 2009). These and other factors regarding fetal programming are discussed in Chapter 44 (p. 876).

image Antepartum Management

Dietary Intervention in Pregnancy

Weight reduction is not advisable during pregnancy (Catalano, 2013). As noted, recommended weight gain in obese women is 11 to 20 pounds, and several dietary interventions to limit weight gain to these targets have been reported. These include lifestyle interventions and physical activity (Petrella, 2013). Reviews by Quinlivan (2011) and Tanentsapf (2011) found that randomized trials generally reported successful results with intervention. On the other hand, in many other studies, either these have been unsuccessful or the results were insufficient to permit a conclusion (Campbell, 2011; Dodd, 2010; Guelinckx, 2010; Nascimento, 2011; Ronnberg, 2010). Special attention to psychological aspects of pregnancy has been recommended by some (Skouteris, 2010).

Prenatal Care

Close prenatal surveillance detects most early signs of diabetes or hypertension. Standard screening tests for fetal anomalies are sufficient, while being mindful of sonographic limitations for detection of fetal anomalies. Accurate assessment of fetal growth usually requires serial sonography. Antepartum and intrapartum external fetal heart rate monitoring are likewise more difficult, and sometimes these are even impossible.

image Surgical and Anesthetic Concerns

Evaluation by the anesthesia team is performed at a prenatal visit or on arrival at the labor unit (American College of Obstetricians and Gynecologists, 2013b). Anesthetic risks and complications faced by obese women are discussed in Chapter 25 (p. 505). Special attention is given to complications that might arise during labor and delivery. Vricella and coworkers (2010) reported the following frequencies of anesthetic complications in 142 morbidly obese women at cesarean delivery. These included technical problems with regional analgesia—up to 6 percent; use of general anesthesia—6 percent; hypotension—3 percent; and overall anesthetic complications of 8.4 percent.

For cesarean delivery, forethought is given to optimal placement and type of abdominal incision to allow access to the fetus and to effect the best wound closure with the least intervening tissue (Alexander, 2006). One technique is shown in Figure 48-7. Others prefer a transverse abdominal incision (Alanis, 2010). Individual differences in maternal body habitus preclude naming any one approach as superior (Gilstrap, 2002; McLean, 2012). Although some have reported similar wound complications with either incision, others reported a fourfold wound complication rate when a vertical abdominal incision was compared with a transverse incision—31 versus 8 percent (Houston, 2000; Thornburg, 2012; Wall, 2003). Finally, a mid-abdomen transverse incision has been advocated by some (Tixier, 2009).

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FIGURE 48-7 Abdominal incision for the obese woman. A. Frontal view. The dotted line indicates an appropriate skin incision for abdominal entry relative to the panniculus. As shown by the uterus in the background, selection of this periumbilical site permits access to the lower uterine segment. B. Sagittal view.

Attention to closure of the subcutaneous layer is important. Chelmow and associates (2004) performed a metaanalysis of subcutaneous closure in 887 women undergoing cesarean delivery whose wound thickness was greater than 2 centimeters. Subcutaneous closure resulted in a modest but significant 6-percent decrease in wound disruption. The frequency of abdominal wound infections is directly related to BMI (Norman, 2013). Comorbid diabetes apparently increases this risk (Leth, 2011). Several reports describe a wound complication rate of 15 to 45 percent. Alanis and colleagues (2010) reported a 30-percent rate in 194 women whose BMI was > 50 kg/m2. Of these, 90-percent were wound disruptions to the fascia, but there was only one evisceration. As indicated above, the transverse abdominal incision had fewer complications. Walsh and coworkers (2009) have reviewed the prevention and management of surgical site infections in morbidly obese women.

To lower thromboembolic complications, graduated compression stockings, hydration, and early mobilization after cesarean delivery in obese women are recommended by the American College of Obstetricians and Gynecologists (2013a). Some also recommend “mini-dose” heparin prophylaxis, but we do not routinely use this (Chap. 52p. 1044).

image Bariatric Surgery

Several surgical procedures have been designed to treat morbid obesity either by decreasing gastric volume—restrictive, or by bypassing gastrointestinal absorption—restrictive malabsorptive (Adams, 2007; Kushner, 2012). In nonpregnant patients, these procedures have been shown to improve or resolve diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea (Buchwald, 2007; Mingrone, 2012; Schauer, 2012).

Pregnancy

Because of these successes, bariatric surgery currently has become popular, and many women are becoming pregnant following weight-reduction surgery (Abodeely, 2008). Several observational studies have reported improved fertility rates and reduced risks of obstetrical complications in women following bariatric surgery and compared with morbidly obese controls (Alatishe, 2013; Guelinckx, 2009; Kjaer, 2013a; Lesko, 2012; Tan, 2012). The largest of these studies is from the Swedish Birth Register, which included 681 women with a pregnancy following bariatric surgery (Josefsson, 2011). Despite surgical treatments, half of these women were still obese by the time of their first pregnancy following bypass, however, the proportion with morbid obesity was smaller. The frequency of large-for-gestational age infants decreased from 9.1 to 3.2 percent and that of small-for-gestational age neonates increasedfrom 2.1 to 5.6 percent. In a recent systematic review, Kjaer and Nilas (2013b) reported a decreased risk after bariatric surgery for diabetes, preeclampsia, and large-for-gestational age infants. Most studies confirmed a higher risk for small-for-gestational age fetuses.

Restrictive Procedures

The prototypical vertical banded gastroplasty has been largely replaced by the laparoscopic adjustable silicone gastric banding (LASGB) operation. With the two approved LASGB procedures—LAPBANDand REALIZE, an adjustable band is placed 2 cm below the gastroesophageal junction to create a small pouch. The pouch size is controlled by a saline reservoir in the band. Salutary effects on pregnancy outcomes involve before-and-after cohorts as well as pregnancies in postsurgical women compared with obese, nonsurgical controls (Vrebosch, 2012). In a report by Dixon and colleagues (2005), pregnancy outcomes were compared with their preprocedural outcomes and with a matched cohort of obese women. Following banding, the incidences of gestational hypertension—10 versus 45 percent—and gestational diabetes—6 versus 15 percent—were significantly lower compared with their preprocedural pregnancies. Incidences in banded patients were also significantly lower than those in the obese cohort, whose rates for hypertension were 38 percent, and for diabetes, 19 percent. The results from these and other studies are shown in Table 48-4.

TABLE 48-4. Pregnancy Outcomes Following Gastric Banding Surgery and Roux-en-Y Gastric Bypass

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Reported complications have been few and include excessive nausea and vomiting that abated with band adjustment (Martin, 2000). Rarely, women may have band slippage associated with hyperemesis or with advancing gestation (Pilone, 2012; Suffee, 2012). One newborn died after fetal cerebral hemorrhage developed from vitamin K deficiency associated with band slippage (Van Mieghem, 2008).

Restrictive Malabsorptive Procedures

There are three procedures to accomplish gastric restriction and selective malabsorption. The most commonly used is the laparoscopically performed Roux-en-Y gastric bypass and biliopancreatic diversion with duodenal switch. With the Roux-en-Y procedure, the proximal stomach is completely transected to leave a 30-mL pouch. A gastroenterotomy is then created by connecting the proximal end of the distal jejunum to the pouch. A Roux-en-Y enteroenterostomy is also completed 60 cm distal to this gastrojejunostomy to allow drainage of the unused stomach and proximal small intestine.

As with other bariatric procedures, pregnancy outcomes are changed remarkably following Roux-en-Y bypass (Wittgrove, 1998). As shown in Table 48-4, rates of hypertension, gestational diabetes, and fetal macrosomia are reduced. Serious complications are uncommon. Intussusception and small bowel obstruction develop from internal herniation, and maternal deaths from herniation and obstruction have been reported (Kakarla, 2005; Moore, 2004; Renault, 2012; Wax, 2007). Bowel obstruction is notoriously difficult to diagnose, and Wax and associates (2013) caution for a high index of suspicion.

Recommendations

The American College of Obstetricians and Gynecologists (2013a) recommends that women who have undergone bariatric surgery be assessed for vitamin and nutritional sufficiency. When indicated, vitamin B12 and D, folic acid, and calcium supplementation are given. Vitamin A deficiency has also been reported (Chagas, 2013). Women with a gastric band should be monitored by their bariatric team during pregnancy because adjustments of the band may be necessary. Finally, special vigilance is appropriate for signs of intestinal obstruction.

REFERENCES

Aagard-Tillery K, Holland W, McKnight R, et al: Fetal origins of disease: essential nutrient supplementation prevents adult metabolic disease in a transgenerational model of IUGR. Am J Obstet Gynecol 195:S3, 2006

Abodeely A, Roye GD, Harrington DT, et al: Pregnancy outcomes after bariatric surgery: maternal, fetal, and infant implications. Surg Obes Relat Dis 4(3):464, 2008

Adams TD, Gress RE, Smith SC, et al: Long-term mortality after gastric bypass surgery. N Engl J Med 357(8):753, 2007

Alanis MC, Villers S, Law TL, et al: Complications of cesarean delivery in the massively obese parturient. Am J Obstet Gynecol 203:271.e1, 2010

Alatishe A, Ammori BJ, New JP, et al: Bariatric surgery in women of childbearing age. QJM 106(8):717, 2013

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

Amador N, Juárez JM, Guizar JM, et al: Quality of life in obese pregnant women: a longitudinal study. Am J Obstet Gynecol 198:203.e1, 2008

American College of Obstetricians and Gynecologists: Weight control: assessment and management. Clinical Updates in Women’s Health Care. Vol II, No. 3, 2003

American College of Obstetricians and Gynecologists: Obesity in pregnancy. Committee Opinion No. 549, January 2013a

American College of Obstetricians and Gynecologists: Obstetric analgesia and anesthesia. Practice Bulletin No. 36, July 2002, Reaffirmed 2013b

American College of Obstetricians and Gynecologists: Weight gain during pregnancy. Committee Opinion No. 548, January 2013c

Bar-Zohar D, Azem F, Klausner J, et al: Pregnancy after laparoscopic adjustable gastric banding: perinatal outcome is favorable also for women with relatively high gestational weight gain. Surg Endosc 20(10):1580, 2006

Bellver J, Ayllón Y, Verrando M, et al: Female obesity impairs in vitro fertilization outcome without affecting embryo quality. Fertil Steril 93(2):447, 2010

Biggio JR Jr, Chapman V, Neely C, et al: Fetal anomalies in obese women: the contribution of diabetes. Obstet Gynecol 115:290, 2010

Boney CM, Verma A, Tucker R, et al: Metabolic syndrome in childhood: association with birth weight, maternal obesity, and gestational diabetes mellitus. Pediatrics 115:e290, 2005

Briana DD, Malamitsi-Puchner A: Adipocytokines in normal and complicated pregnancies. Reprod Sci 16(10):921, 2009

Browning JD, Szczepaniak LS, Dobbins R, et al: Prevalence of hepatic steatosis in an urban population in the United States: impact of ethnicity. Hepatology 40:1387, 2004

Buchwald H, Estok R. Fahrbach K, et al: Trends in mortality in bariatric surgery: a systematic review and meta-analysis. Surgery 142(4):621, 2007

Bujold E, Hammoud A, Schild C, et al: The role of maternal body mass index in outcomes of vaginal births after cesarean. Am J Obstet Gynecol 193(4):1517, 2005

Butte NF, Wong WW, Treuth MS, et al: Energy requirements during pregnancy based on total energy expenditure and energy deposition. Am J Clin Nutr 79:1078, 2004

Calle EE, Rodriguez C, Walker-Thurmond K, et al: Overweight, obesity, and mortality from cancer in a prospectively studied cohort of U.S. adults. N Engl J Med 348:1625, 2003

Calle EE, Teras LR, Thun MJ: Obesity and mortality. N Engl J Med 353:20, 2005

Campbell F, Johnson M, Messina J, et al: Behavioural interventions for weight management in pregnancy: a systematic review of quantitative and qualitative data. BMC Public Health 11:491, 2011

Catalano P: Weight loss in overweight and obese pregnant women (OW/OB): what is the effect on fetal growth? Abstract No. 349. Am J Obstet Gynecol 208(1):S155, 2013

Catalano P, Farrell K, Presley L, et al: Long-term follow-up of infants of women with normal glucose tolerance (NGT) and gestational diabetes (GDM): risk factors for obesity and components of the metabolic syndrome in childhood. Am J Obstet Gynecol 193:S3, 2005

Catalano PM: Management of obesity in pregnancy. Obstet Gynecol 109:419, 2007

Catalano PM: Obesity, insulin resistance, and pregnancy outcome. Reproduction 140(3):365, 2010

Cedergren MI: Maternal morbid obesity and the risk of adverse pregnancy outcome. Obstet Gynecol. 103:219, 2004

Chagas CB, Saunders C, Pereira S, et al: Vitamin A deficiency in pregnancy: perspectives after bariatric surgery. Obes Surg 23(2):249, 2013

Chelmow D, Rodriquez EJ, Sabatini MM: Suture closure of subcutaneous fat and wound disruption after cesarean delivery: a meta-analysis. Obstet Gynecol 103:974, 2004

Chinali M, Devereux RB, Howard BV, et al: Comparison of cardiac structure and function in American Indians with and without the metabolic syndrome (the Strong Heart Study). Am J Cardiol 93:40, 2004

Chu SY, Callaghan WM, Bish CL, et al: Gestational weight gain by body mass index among US women delivering live births, 2004–2005: fueling future obesity. Am J Obstet Gynecol 200:271.e1, 2009

Chu SY, Kim SY, Lau J, et al: Maternal obesity and risk of stillbirth: a metaanalysis. Am J Obstet Gynecol 197(3):223, 2007

Cnattingius S, Bergstrom R, Lipworth L, et al: Prepregnancy weight and the risk of adverse pregnancy outcomes. N Engl J Med 338: 147, 1998

Cornier MA, Després JP, Davis N, et al: Assessing adiposity: a scientific statement from the American Heart Association. Circulation 124:00, 2011

Crane J, Murphy P, Burrage L, et al: Maternal and perinatal complications of super-obesity (BMI at least 50.00 kg/m2). Abstract No. 669. Am J Obstet Gynecol 208(1):S282, 2013

Crist LA, Champagne CM, Corsino L, et al: Influence of change in aerobic fitness and weight on prevalence of metabolic syndrome. Prev Chronic Dis 9:E68, 2012

Cunningham FG: Peripartum cardiomyopathy: we’ve come a long way, but. … Obstet Gynecol 120(5):992, 2012

Cunningham FG, Pritchard JA, Hankins GVD, et al: Idiopathic cardiomyopathy or compounding cardiovascular events? Obstet Gynecol 67:157, 1986

Dark AC, Miller L, Kothenbeutel RL, et al: Obesity and second-trimester abortion by dilation and evacuation. J Reprod Med 47:226, 2002

Dashe JS, McIntire DD, Twickler DM: Effect of maternal obesity on the ultrasound detection of anomalous fetuses. Obstet Gynecol 113:1, 2009

De Gonzalez AB, Hartge P, Cherhan JR, et al: Body mass index and mortality among 1.46 million white adults. N Engl J Med 363:23, 2010

Denison FC, Price J, Graham C, et al: Maternal obesity, length of gestation, risk of postdates pregnancy and spontaneous onset of labour at term. BJOG 115(6):720, 2008

Dixon JB, Dixon ME, O’Brien PE: Birth outcomes in obese women after laparoscopic adjustable gastric banding. Obstet Gynecol 106:965, 2005

Dixon JB, Dixon ME, O’Brien PE: Pregnancy after Lap-Band surgery: management of the band to achieve healthy weight outcomes. Obes Surg 11:59, 2001

Dodd JM, Grivell RM, Crowther CA, et al: Antenatal interventions for overweight or obese pregnant women: a systematic review of randomised trials. BJOG 117(11):1316, 2010

Drewnowski A, Specter SE: Poverty and obesity: the role of energy density and energy costs. Am J Clin Nutr 79:6, 2004

Ducarme G, Parisio L, Santulli P, et al: Neonatal outcomes in pregnancies after bariatric surgery: a retrospective multi-centric cohort study in three French referral centers. J Matern Fetal Neonatal Med 26(3):275, 2013

Eckel RH: Nonsurgical management of obesity in adults. N Engl J Med 358:1941, 2008

Edlow A, Neeta V, Hui L, et al: Antenatal origins of metabolic syndrome in fetuses of obese women. Abstract No. 4. Am J Obstet Gynecol 208(1):S3, 2013

Ehrenberg HM, Dierker L, Milluzzi C, et al: Prevalence of maternal obesity in an urban center. Am J Obstet Gynecol 187:1189, 2002

Ehrenberg HM, Mercer BM, Catalano PM: The influence of obesity and diabetes on the prevalence of macrosomia. Am J Obstet Gynecol 191:964, 2004

Flegal KM, Carroll MD, Kit BK, Ogden CL: Prevalence of obesity and trends in body mass index among US adults, 1999–2000. JAMA 307(5):491, 2012

Flegal KM, Graubard BI, Williamson DF, et al: Cause-specific excess deaths associated with underweight, overweight, and obesity. JAMA 298:2028, 2007

Flenady V, Koopmans L, Middleton P, et al: Major risk factors for stillbirth in high-income countries: a systematic review and meta-analysis. Lancet 377(9774):1331, 2011

Fontaine KR, Redden DT, Wang C, et al: Years of life lost due to obesity. JAMA 289:187, 2003

Forbes S, Taylor-Robinson SD, Patel N, et al: Increased prevalence of non-alcoholic fatty liver disease in European women with a history of gestational diabetes. Diabetologia 54(3):641, 2011

Ford ES, Giles WH, Dietz WH: Prevalence of the metabolic syndrome among U.S. adults. Findings from the Third National Health and Nutrition Examination Survey. JAMA 287:356, 2002

Garabedian MJ, Williams CM, Pearce CF, et al: Extreme morbid obesity and labor outcome in nulliparous women at term. Am J Perinatol 28(9):729, 2011

Gilboa SM, Correa A, Botto LD, et al: Association between prepregnancy body mass index and congenital heart defects. Am J Obstet Gynecol 202(1):51.e1, 2010

Gilstrap LC, Cunningham FG, Van Dorsten JP (eds): Anatomy, incisions, and closures. In Operative Obstetrics, 2nd ed. New York, McGraw-Hill, 2002, p 55

Gluck ME, Venti CA, Lindsay RS, et al: Maternal influence, not diabetic intrauterine environment, predicts children’s energy intake. Obesity 17:772, 2009

Goodall PT, Ahn JT, Chapa JB, et al: Obesity as a risk factor for failed trial of labor in patients with previous cesarean delivery. Am J Obstet Gynecol 192:1423, 2005

Guelinckx I, Devlieger R, Mullie P, et al: Effect of lifestyle intervention on dietary habits, physical activity, and gestational weight gain in obese pregnant women: a randomized controlled trial. Am J Clin Nutr 91(2):373, 2010

Guelinckx I, Devlieger R, Vansant G: Reproductive outcome after bariatric surgery: a critical review. Hum Reprod Update 15(2):189, 2009

Haeri S, Guichard I, Baker AM, et al: The effect of teenage maternal obesity on perinatal outcomes. Obstet Gynecol 113:300, 2009

Hall LF, Neubert AG: Obesity and pregnancy. Obstet Gynecol Surv 60(4):253, 2005

Hibbard JU, Gilbert S, Landon MB, et al: Trial of labor or repeat cesarean delivery in women with morbid obesity and previous cesarean delivery. Obstet Gynecol 108(1):125, 2006

Hood DD, Dewan DM: Anesthetic and obstetric outcome in morbidly obese parturients. Anesthesiology 79:1210, 1993

Hossain P, Kawar B, El Nahas M: Obesity and diabetes in the developing world—a growing challenge. N Engl J Med 356(9):973, 2007

Houston MC, Raynor BD: Postoperative morbidity in the morbidly obese parturient woman: supraumbilical and low transverse abdominal approaches. Am J Obstet Gynecol 182(5):1033, 2000

Huang DY, Usher RH, Kramer MS, et al: Determinants of unexplained antepartum fetal deaths. Obstet Gynecol 95:215, 2000

Institute of Medicine: The development of DRIs 1994–2004: lessons learned and new challenges. Workshop summary. November 30, 2007

Institute of Medicine: Weight gain during pregnancy: reexamining the guidelines. National Academy of Sciences. 28 May 2009

Johnson J, Clifton RB, Roberts JM, et al: Pregnancy outcomes with weight gain above or below the 2009 Institute of Medicine guidelines. Obstet Gynecol 121:969, 2013

Jordan HT, Tabaei BP, Nash D, et al: Metabolic syndrome among adults in New York City, 2004 New York City Health and Nutrition Examination Survey. Prev Chronic Dis 9:E04, 2012

Josefsson A, Blomberg M, Bladh M, et al: Bariatric surgery in a national cohort of women: sociodemographics and obstetric outcomes. Am J Obstet Gynecol 205(5):206.e1, 2011

Kabiru W, Raynor BD: Obstetric outcomes associated with increase in BMI category during pregnancy. Am J Obstet Gynecol 191:928, 2004

Kakarla N, Dailey C, Marino T, et al: Pregnancy after gastric bypass surgery and internal hernia formation. Obstet Gynecol 105(5, Part 2):1195, 2005

Kenchaiah S, Evans JC, Levy D, et al: Obesity and the risk of heart failure. N Engl J Med 347:305, 2002

Kinoshita T, Itoh M: Longitudinal variance of fat mass deposition during pregnancy evaluated by ultrasonography: the ratio of visceral fat to subcutaneous fat in the abdomen. Gynecol Obstet Invest 61:115, 2006

Kjaer MM, Lauenborg J, Breum BM, et al: The risk of adverse pregnancy outcome after bariatric surgery: a nationwide register-based matched cohort study. Am J Obstet Gynecol 208(6):464.e1, 2013a

Kjaer MM, Nilas L: Pregnancy after bariatric surgery—a review of benefits and risks. Acta Obstet Gynecol Scand 92(3):264, 2013b

Kumari AS: Pregnancy outcome in women with morbid obesity. Int J Gynaecol Obstet 73:101, 2001

Kushner RF: Evaluation and management of obesity. In Longo DL, Fauci AS, Kasper DL, et al (eds): Harrison’s Principles of Internal Medicine, 18th ed. McGraw-Hill, New York, 2012, p. 629

LaCoursiere Y, Varner M: The association between prepregnancy obesity and postpartum depression, supported by NIH grant R03-HD-048865. Abstract No. 92. Presented at the 29th Annual Meeting of the Society for Maternal-Fetal Medicine. 26–31 January 2009

Lashen H, Fear K, Sturdee DW: Obesity is associated with increased risk of first trimester and recurrent miscarriage: matched case-control study. Hum Reprod 19:1644, 2004

Lesko J, Peaceman A: Pregnancy outcomes in women after bariatric surgery compared with obese and morbidly obese controls. Obstet Gynecol 119(3):547, 2012

Leth RA, Uldbjerg N, Norgaard M, et al: Obesity, diabetes, and the risk of infections diagnosed in hospital and post-discharge infections after cesarean section: a prospective cohort study. Acta Obstet Gynecol Scand 90(5):501, 2011

Li R, Jewell S, Grummer-Strawn L: Maternal obesity and breast-feeding practices. Am J Clin Nutr 77:931, 2003

Lipkind H, Campbell K, Savitz D, et al: Obesity as an independent risk factor for severe maternal morbidity (“near miss”) during delivery hospitalization. Abstract No. 666. Am J Obstet Gynecol 208(1):S281, 2013

Lu GC, Rouse DJ, DuBard M, et al: The effect of the increasing prevalence of maternal obesity on perinatal morbidity. Am J Obstet Gynecol 185(4):845, 2001

Lynch CM, Sexton DJ, Hession M, et al: Obesity and mode of delivery in primigravid and multigravid women. Am J Perinatol 25(3):163, 2008

McDonald SD, Han Z, Mulla S, et al: Overweight and obesity in mothers and risk of preterm birth and low birth weight infants: systematic review and meta-analyses. BMJ 341:c3428, 2010

Mace HS, Paech MJ, McDonnell NJ: Obesity and obstetric anaesthesia. Anaesth Intensive Care 39(4):559, 2011

Maguire M, Lungu A, Gorden P, et al: Pregnancy in women with congenital generalized lipodystrophy. Leptin’s vital role in reproduction. Obstet Gynecol 119(2 Pt 2):452, 2012

Martin LF, Finigan KM, Nolan TE: Pregnancy after adjustable gastric banding. Obstet Gynecol 95:927, 2000

McLean M, Hines R, Polinkovsky M, et al: Type of skin incision and wound complications in the obese parturient. Am J Perinatol 29(4):301, 2012

Metwally M, Ong KJ, Ledger WL, et al: Does high body mass index increase the risk of miscarriage after spontaneous and assisted conception? A meta-analysis of the evidence. Fertil Steril 88:446, 2008

Meyer BJ, Stewart FM, Brown EA, et al: Maternal obesity is associated with the formation of small dense LDL and hypoadiponectinemia in the third trimester. J Clin Endocrinol Metab 98(2):643, 2013

Mingrone G, Panunzi s, De Gaetano A, et al: Bariatric surgery versus conventional medical therapy for Type 2 diabetes. N Engl J Med 366(17):1577, 2012

Moore KA, Ouyang DW, Whang EE: Maternal and fetal deaths after gastric bypass surgery for morbid obesity. N Engl J Med 351:721, 2004

Nascimento SL, Surita FG, Parpinelli MÂ, et al: The effect of an antenatal exercise programme on maternal/perinatal outcomes and quality of life in overweight and obese women: a randomised clinical trial. BJOG 118(12):1455, 2011

National Institutes of Health: The practical guide: identification, evaluation, and treatment of overweight and obesity in adults. NIH Publication 00-4084. Bethesda, National Institutes of Health, 2000

National Institutes of Health: Third report of the National Cholesterol Education Program Expert Panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III), NIH Publication 01-3670. Bethesda, National Institutes of Health, 2001

National Research Council and Institute of Medicine: Influence of pregnancy weight on maternal and child health. Workshop report. Committee on the Impact of Pregnancy Weight on Maternal and Child Health. Board on Children, Youth, and Families, Division of Behavioral and Social Sciences and Education and Food and Nutrition Board, Institute of Medicine. Washington, The National Academies Press, 2007

National Task Force on the Prevention and Treatment of Obesity: Overweight, obesity, and health risk. Arch Intern Med 160:898, 2000

Nehring I, Schmoll S, Beyerlein A, et al: Gestational weight gain and long-term postpartum weight retention: a meta-analysis. Am J Clin Nutr 94(5):1225, 2011

Neill AM, Nelson-Piercy C: Hazards of assisted conception in women with severe medical disease. Hum Fertil (Camb) 4:239, 2001

Ninomiya JK, L’Italien G, Criqui MH, et al: Association of the metabolic syndrome with history of myocardial infarction and stroke in the Third National Health and Nutrition Examination Survey. Circulation 109:42, 2004

Nohr EA, Bech BH, Davies MJ, et al: Pregnancy obesity and fetal death: a study within the Danish National Birth Cohort. Obstet Gynecol 106:250, 2005

Norman S, Verticchio J, Odibo A: The effects of degree of obesity on risk for post-cesarean wound complication. Abstract No. 157. Am J Obstet Gynecol 208(1):S78, 2013

O’Brien TE, Ray JG, Chan WS: Maternal body mass index and the risk of preeclampsia: a systematic overview. Epidemiology 14:368, 2003

Ogden CL, Carroll MD, Kit BK, et al: Prevalence of obesity in the United States, 2009–2010. NCHS data brief No. 82, Hyattsville, National Center for Health Statistics, 2012

Oken E: Maternal weight and gestational weight gain as predictors of long-term off-spring growth and health. Presentation at the Workshop on the Impact of Pregnancy Weight on Maternal and Child Health, May 30, Washington, 2006

Ovesen P, Rasmussen S, Kesmodel U: Effect of prepregnancy maternal overweight and obesity on pregnancy outcome. Obstet Gynecol 118(2 Pt 2):305, 2011

Page LM, Girling JC: A novel cause for abnormal liver function tests in pregnancy and the puerperium: non-alcoholic fatty liver disease. BJOG 118(12):1532, 2011

Pauli J, Zhu Junjia, Repke J, et al: Health care utilization during pregnancy: the impact of pre-pregnancy body mass index. Abstract No. 344. Am J Obstet Gynecol 208(1):S153, 2013

Peeters A, Barendregt JJ, Willekens F, et al: Obesity in adulthood and its consequences for life expectancy: a life-table analysis. Ann Intern Med 138:24, 2003

Petrella E, Facchinetti F, Bertarini V, et al: Occurrence of pregnancy complications in women with BMI > 25 submitted to a healthy lifestyle and eating habits program. Abstract No. 55. Am J Obstet Gynecol 208(1):S33, 2013

Pilone V, Di Micco R, Monda A, et al: LAGB in pregnancy: slippage after hyperemesis gravidarum. Report of a case. Ann Ital Chir 83(5):429, 2012

Poobalan AS, Aucott LS, Gurung T, et al: Obesity as an independent risk factor for elective and emergency caesarean delivery in nulliparous women—systematic review and meta-analysis of cohort studies. Obes Rev 10:28, 2009

Public Health Service: Healthy People 2000: National Health Promotion and Disease Prevention Objectives. Washington, U.S. Department of Health and Human Services, Public Health Service, DHHS Publication No. (PHS) 90–50212, 1990

Quinlivan JA, Julania S, Lam L: Antenatal dietary interventions in obese pregnant women to restrict gestational weight gain to Institute of Medicine recommendations. Obstet Gynecol 118(6):1395, 2011

Ramsay JE, Ferrell WR, Crawford L, et al: Maternal obesity is associated with dysregulation of metabolic, vascular, and inflammatory pathways. J Clin Endocrinol Metab 87:4231, 2002

Rasmussen KM, Abrams B, Bodnar LM, et al: Recommendations for weight gain during pregnancy in the context of the obesity epidemic. Obstet Gynecol 116(5):1191, 2010

Rasmussen SA, Chu SY, Kim SY, et al: Maternal obesity and risk of neural tube defects: a metaanalysis. Am J Obstet Gynecol 198(6):611, 2008

Renault K, Gyrtrup HJ, Damgaard K, et al: Pregnant women with fatal complication after laparoscopic Roux-en-Y gastric bypass. Acta Obstet Gynecol Scand 91(7):873, 2012

Reynolds RM, Allan KM, Raja EA, et al: Maternal obesity during pregnancy and premature mortality from cardiovascular event in adult offspring: follow-up of 1 323 275 person years. BMJ 347:f4539, 2013

Robinson HE, O’Connell CM, Joseph KS, et al: Maternal outcomes in pregnancies complicated by obesity. Obstet Gynecol 106(6):1357, 2005

Rode L, Nilas L, Wøjdemann K, et al: Obesity-related complications in Danish single cephalic term pregnancies. Obstet Gynecol 105:537, 2005

Ronnberg AK, Nilsson K: Interventions during pregnancy to reduce excessive gestational weight gain: a systematic review assessing current clinical evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. BJOG 117(11):1327, 2010

Rooney BL, Schauberger CW: Excess pregnancy weight gain and long-term obesity: one decade later. Obstet Gynecol 100:245, 2002

Schack-Nielsen L, Mortensen EL, Sorensen TIA: High maternal pregnancy weight gain is associated with an increased risk of obesity in childhood and adulthood independent of maternal BMI. Pediatric Res 58:1020, 2005

Schauer PR, Kashyap SR, Wolski K, et al: Bariatric surgery versus intensive medical therapy in obese patients with diabetes. N Engl J Med 366(17):1567, 2012

Scherer PE, Williams S, Fogliano M, et al: A novel serum protein similar to C1q, produced exclusively in adipocytes. J Biol Chem 270:26746, 2006

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 25:1175, 2001

Sewell MF, Huston-Presley L, Super DM, et al: Increased neonatal fat mass, not lean body mass, is associated with maternal obesity. Am J Obstet Gynecol 195:1100, 2006

Skouteris H, Hartley-Clark L, McCabe M, et al: Preventing excessive gestational weight gain: a systematic review of interventions. Obes Rev 11(11):757, 2010

Skull AJ, Slater GH, Duncombe JE, et al: Laparoscopic adjustable banding in pregnancy: safety, patient tolerance and effect on obesity-related pregnancy outcomes. Obes Surg 14:230, 2004

Stamilio D, Stout M, Macones G, et al: Post-cesarean maternal complications in patients with extreme obesity. Abstract No. 754. Am J Obstet Gynecol 208(1):S317, 2013

Stephansson O, Dickman PW, Johansson A, et al: Maternal weight, pregnancy weight gain, and the risk of antepartum stillbirth. Am J Obstet Gynecol 184:463, 2001

Stothard KJ, Tennant PW, Bell R, et al: Maternal overweight and obesity and the risk of congenital anomalies: a systematic review and meta-analysis. JAMA 301:636, 2009

Suffee MT, Poncelet C, Barrat C: Gastric band slippage at 30 weeks’ gestation: diagnosis and laparoscopic management. Surg Obes Relat Dis 8(3):366, 2012

Tan O, Carr BR: The impact of bariatric surgery on obesity-related infertility and in vitro fertilization outcomes. Semin Reprod Med 30(6):517, 2012

Tanentsapf I, Heitmann BL, Adegboye AR: Systematic review of clinical trials of dietary interventions to prevent excessive weight gain during pregnancy among normal weight, overweight and obese women. BMC Pregnancy Childbirth 11:81, 2011

Targher G, Day CP, Bonora E: Risk of cardiovascular disease in patients with nonalcoholic fatty liver disease. N Engl J Med 363(14):1341, 2010

The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study Cooperative Research Group: Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study: preeclampsia. Am J Obstet Gynecol 202:255.e1, 2010

Thornburg L, Mulconry M, Grace M, et al: Nuchal translucency measurements in the obese gravida. Abstract No. 456. Presented at the 29th Annual Meeting of the Society for Maternal-Fetal Medicine. January 26–31, 2009

Thornburg LL, Linder MA, Durie DE, et al: Risk factors for wound complications in morbidly obese women undergoing primary cesarean delivery. J Matern Fetal Neonatal Med 25(9):1544, 2012

Tixier H, Thouvenot S, Coulange L, et al: Cesarean section in morbidly obese women: supra or subumbilical transverse incision? Acta Obstet Gynecol Scand 88(9):1049, 2009

Van Mieghem T, Van Schoubroeck D, Depiere M, et al: Fetal cerebral hemorrhage caused by vitamin K deficiency after complicated bariatric surgery. Obstet Gynecol 112:434, 2008

Verrijken A, Mertens FS, Prawitt J, et al: Prothrombotic factors in histologically proven nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Hepatology 59:121, 2014

Vesco K, Sharma A, Dietz P, et al: Newborn size among obese women with weight gain outside the 2009 Institute of Medicine recommendation. Obstet Gynecol 117(4):812, 2011

Vrebosch L, Bel S, Vansant G et al: Maternal and neonatal outcome after laparoscopic adjustable gastric banding: a systematic review. Obes Surg 22(10):1568, 2012

Vricella LK, Louis JM, Mercer BM, et al: Anesthesia complications during scheduled cesarean delivery for morbidly obese women. Am J Obstet Gynecol 203(3):276.e1, 2010

Waldenström U, Aasheim V, Nilson ABV, et al: Adverse pregnancy outcomes related to advanced maternal age compared with smoking and being overweight. Obstet Gynecol 123:104, 2014

Wall PD, Deucy EE, Glantz JC, et al: Vertical skin incisions and wound complications in the obese parturient. Obstet Gynecol 102:952, 2003

Walsh C, Scaife C, Hopf H: Prevention and management of surgical site infection in morbidly obese women. Obstet Gynecol 113:411, 2009

Wang T, Zhang J, Lu X, et al: Maternal early pregnancy body mass index and risk of preterm birth. Arch Gynecol Obstet 284(4):813, 2011

Watkins ML, Rasmussen SA, Honein MA, et al: Maternal obesity and risk for birth defects. Pediatrics 111:1152, 2003

Wax JF, Pinette MG, Cartin A: Roux-en-Y gastric bypass-associated bowel obstruction complicating pregnancy–an obstetrician’s map to the clinical minefield. Am J Obstet Gynecol 208(4):265, 2013

Wax JR, Wolff R, Cobean R, et al: Intussusception complicating pregnancy following laparoscopy Roux-en-Y gastric bypass. Obes Surg 17(7):977, 2007

Weichert J, Hartge DR: Obstetrical sonography in obese women: a review. J Clin Ultrasound 39(4):209, 2011

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

Whitaker RC: Predicting preschooler obesity at birth: the role of maternal obesity in early pregnancy. Pediatrics 114:e29, 2004

Wittgrove AC, Jester L, Wittgrove P, et al: Pregnancy following gastric bypass for morbid obesity. Obes Surg 8:461, 1998

Wolf M, Kettyle E, Sandler L, et al: Obesity and preeclampsia: the potential role of inflammation. Obstet Gynecol 98:757, 2001

Yao R, Ananth C, Park B, et al: Obesity and the risk of still birth: a population-based cohort study. Am J Obstet Gynecol 210:S31, 2014

Yanovski SZ: Pharmacotherapy for obesity—promise and uncertainty. N Engl J Med 353(20):2187, 2005

Zimmet P, Alberti KGMM: Surgery or medical therapy for obese patients with Type 2 diabetes? N Engl J Med 366(17):1635, 2012