Management Overview of Pregnancy Complicated by Maternal Obesity
by Jarin Leavitt, MD, and Jordan H. Perlow, MD
Dr. Jarin Leavitt is from the Department of Obstetrics and Gynecology, Banner Good Samaritan Medical Center, Phoenix, Arizona. Dr. Jordan H. Perlow is Director of the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Banner Good Samaritan Medical Center, Phoenix, Arizona, and Partner, Phoenix Perinatal Associates, Obstetrix Medical Group of Phoenix, Phoenix, Arizona.
Funding: No funding was provided.
Disclosures: The authors report no conflicts of interest relevant to the content of this article.
Bariatric Times. 2014;11(3):8–14.
Abstract
The overall trend toward a higher incidence of obesity in the general population naturally results in an increased prevalence of obesity complicating pregnancy. Rates of obesity vary by geographic region, and disparity is also noted among different socioeconomic and racial/ethnic groups. Obesity imparts an ever-present risk for adverse health outcomes for the woman who becomes pregnant and is not of a normal body mass index. Given the clinical risk issues with which the obese gravida presents, special attention and care is required in the rendering of prenatal care so as to achieve the best perinatal outcome possible. Obesity places a pregnant patient at risk for many serious complications of pregnancy, including maternal and fetal mortality. Management of the obese gravida requires special consideration and treatment adjustment to minimize these risks.
Background
The overall trend toward a higher incidence of obesity in the general population naturally results in an increased prevalence of obesity complicating pregnancy.[1] A sedentary lifestyle combined with poor dietary choices and a lack of regular exercise creates a situation in which the current obesity epidemic thrives. Despite increased awareness, obesity continues to grow in prevalence. New “quick fix” diet plans seem to appear every day with no improvement in the incidence of obesity. According to the Centers for Disease Control and Prevention (CDC), United States obesity (body mass index [BMI] >30kg/m2) prevalence varies by region with higher prevalence noted in states in the Midwest and South, and a lesser prevalence seen in the northwest and western states. However, even among the “healthier” states prevalence is still noted to be greater than 20 percent.[2] According to 2012 data from the CDC, the state with the lowest prevalence of obesity is Colorado at 20.5 percent, and the highest is Louisiana at 34.7 percent.
The differentiation of obesity “degrees” into classes helps stratify risk and estimate complication occurrence, and furthermore, allows for appropriate comparisons in health outcomes to be reached within populations. Definitions of obesity and the degree to which it has an effect on health are used as an important indicator of risk. Overweight is defined as BMI between 25.0 and 29.9kg/m².
Obesity is defined as BMI greater than or equal to 30kg/m². Subcategories of obesity as follows: class I—BMI 30.0 to 34.9kg/m2, class II—BMI 35.0 to 39.9kg/m2, and class III (also termed extreme obesity)—BMI greater than or equal to 40.0kg/m2. The term super-obesity is used to define a BMI greater than 50.3kg/m2.
Obesity and Pregnancy: Overview
Currently, obesity complicates up to 28 percent of pregnancies, with eight percent categorized as extremely obese (BMI greater than 40kg/m²). The obese gravida is at increased risk for many serious complications, including gestational diabetes, hypertensive disorders in pregnancy, fetal macrosomia, shoulder dystocia, birth trauma, fetal malformations, protracted labor, emergent cesarean delivery, postpartum hemorrhage, venous thromboembolism, and infection risk.[4–7] Also, those who undergo cesarean delivery are at increased risk of significant operative morbidity that may include greater blood loss, longer operative times, anesthetic complications, and postoperative wound infections.[5,7,8] Data has also shown a trend of an increased risk for childhood obesity and diabetes for those born to individuals with overweight and obesity.[9] Obesity complicating pregnancy has also been noted to independently increase the risk for spontaneous preterm birth[10] In fact, essentially every potential pregnancy complication is, to varying degrees, increased in the setting of obesity.
Pregnancy management
The approach to management of the obese gravid woman is multifaceted. Further complicating the picture are historic misperceptions regarding weight gain during pregnancy. For example, as cited by Flick and Artel,[11] traditional thought has been that even in the patient population with obesity, maternal weight gain should be “net positive” to reflect the weight of the products of conception and increased uterine size. Studies have shown, however, that women with overweight and obesity are able to generate the necessary increase in caloric intake needed from their own reserves.[11,12]
Preconception
Women with obesity who desire to become pregnant should be counseled regarding the increased risk to their health and future offspring should pregnancy occur in the setting of obesity. Measures should be taken to initiate weight loss and achieve a normal BMI before conception. Women should be thoroughly counseled regarding the higher likelihood for serious adverse health outcomes, including maternal mortality, preterm birth and its sequelae, hypertensive disorders of pregnancy, fetal growth aberrations, congenital malformation, and stillbirth.[13] Several large studies have demonstrated that weight reduction is an important factor for these women to reduce risk for perinatal complications. For example, an increase in pregravid weight between the first and second pregnancies was shown to increase the risk of development of preeclampsia with the subsequent pregnancy, while a decrease in pregravid weight between pregnancies resulted in a decreased risk for cesarean delivery and large for gestational age infants.[14–16] In addition, increased pregravid BMI is associated with many maternal metabolic disorders, including diabetes mellitus, hypertension, and hyperlipidemia.[17] The increased incidence of these and other potential maternal health factors undoubtedly places the patient at risk during her pregnancy.
It is important to note that patients with overweight and obesity often have higher rates of infertility, and thus, when seeking treatment for such, are found to require increased doses of medication to stimulate successful ovulation.[18] The infertility specialist is found in an ideal situation because the patient will seek medical attention prior to conception providing opportunity for improvement in maternal weight. They should in no uncertain terms be counseled that attainment of a normal BMI prior to conception is recommended to achieve the best pregnancy outcome possible. Furthermore, the patient with obesity conceiving a multiple gestation, certainly more likely in the setting of assisted reproductive technology, will face even further increased risks for adverse perinatal outcome, and thus, a goal of management should undoubtedly be the avoidance of multiple gestation. In otherwise healthy individuals, preconception counseling is nearly nonexistent as the typical first prenatal visit occurs in the first trimester. Fertility specialists should include maternal weight loss recommendations in their routine counseling and consider successful weight loss a prerequisite to intervention. The American College of Obstetricians and Gynecologists (ACOG) recommends a healthy diet with daily aerobic exercise to achieve those goals.[13] Referral to a bariatric physician should be considered to discuss all options for management to achieve normal weight.
Patients who have undergone bariatric surgery require special attention. General considerations for pregnancy after bariatric surgery are that the patient should wait 12 to 18 months prior to conception to decrease fetal exposure to rapid weight loss.[19] It should also be noted that patients who have undergone Roux-en-Y bypass or similar surgery are at increased risk for malabsorption syndromes. It is all the more important for these patients to have adequate vitamin supplementation, including vitamins B12, B6, B1, D, folic acid, calcium, and iron.[19] It has also been suggested that four high-protein meals are preferred over six meals daily.[19] Pregnancy related changes in upper GI function may necessitate evaluation of adjustable gastric bands to determine if such changes may help alleviate symptoms. Laparoscopic adjustment of gastric bands is generally considered safe, particularly in the second trimester.[20]
Post-bariatric surgery complications, including bowel obstruction and maternal and fetal death, have been reported during pregnancy.[21,22] Most cases occurred in women who had Roux-en-Y bypass surgery and involved internal herniation; however, other cases have included volvulus, band slippage, and intussusception with bowel necrosis.[23–25] Problems with detecting such complications in pregnancy are due to symptoms mimicking common pregnancy complaints, such as nausea, gastro-esophageal reflux, generalized abdominal discomfort, and contractions. Experts suggest a low threshold for surgical evaluation and computed tomography (CT) imaging in patients with a history or physical exam concerning for possible bowel obstruction in the setting of a history of prior bariatric surgery. Even with negative imaging studies, providers should maintain a high degree of suspicion in these patients and early consultation with a general or bariatric surgeon is recommended.[26]
First Trimester Care
The National Institutes of Health (NIH) recommends initiating prenatal care in the first trimester with the goal of 90 percent of all first visits occurring during this important time.[27] According to The National Vital Statistics report published in 2011, it was estimated that overall rate of first trimester presentation to prenatal care was only 71 percent, significantly less than the goal of 90 percent.[28] Screening for maternal disorders early in pregnancy is of particular importance in the population with obesity, as evidenced by the plethora of comorbidities with which they present and which can complicate perinatal outcome. Early ultrasound to verify intrauterine gestation and plurality of pregnancy, and to establish pregnancy dating is important on entry to obstetric care. Increased rates of ovulatory dysfunction in individuals with overweight and obesity make dating of the pregnancy particularly important.[29,30] Screening for pregestational medical conditions is also an important undertaking early in prenatal care. Screening should be employed for diabetes, hypertension, thyroid disorders, sleep apnea, and cardiac disease along with any other medical comorbidity for which there exists a high degree of suspicion. Experts also recommend routine baseline lab work to include uric acid, creatinine, hepatic transaminases, and 24-hour urine protein.[31] It has also been suggested that individuals with extreme obesity (class III) could benefit from maternal echocardiography, to determine the existence of cardiomyopathy, especially for those patient with longstanding history of obesity comorbidities (diabetes and/or hypertension).[32,33]
In patients who have undergone bariatric surgery, baseline chemistry and nutritional status evaluation should be accomplished.[19] Individualized counseling regarding pregnancy risks should be discussed with the patient early in pregnancy. Goals of care and a management plan should be reviewed. Given the significantly increased risk for preeclampsia, patients should be counseled on the potential benefits of daily low-dose aspirin in reducing this in high-risk groups.[34]
Second Trimester Care
During the second trimester, full and adequate evaluation of fetal anatomy should be attempted. A multitude of congenital malformations occur more commonly in pregnancies complicated by obesity. Fetal malformations, including cardiac and neural tube defects, have been shown to be associated with obesity. Other malformations, including omphalocele, diaphragmatic hernia, cystic kidney, and orofacial clefts, have also shown significant correlation with obesity.[35–39] Given the difficulty in achieving adequate sonographic visualization due to the suboptimal image clarity, expert opinion suggests imaging no earlier than 20 to 22 weeks gestation.31 Some have suggested that only about 50 percent of ultrasound studies of women with obesity result in complete and adequate fetal assessment.[40] In the non-obese gravid patient, serial fundal height measurement provides some indication that fetal growth is adequate.[41] This is typically initiated in the second trimester during routine prenatal checkups. In the population with obesity, however, fundal height is difficult to accurately assess given the degree of abdominal adipose tissue. Therefore, serial ultrasounds for the evaluation of fetal growth should be performed at approximate monthly intervals to accurately assess appropriateness of fetal growth, or aberrations thereof. Given the marked increased risk for fetal neural tube defects, maternal serum alpha-feto-protein evaluation is recommended.[42]
Third Trimester Care
As a BMI greater than 30kg/m2 significantly increases the risk for virtually all adverse outcomes, third trimester care differs between women with and without obesity. A focus on the avoidance of stillbirth, detection of diabetes and preeclampsia, and ongoing monitoring for the adequacy of fetal growth are key components of third trimester prenatal surveillance. Compared to normal weight women, women with obesity are at increased risk of stillbirth with an odds ratio of 2.8.[43] Intrauterine fetal death is more common even after correctioning for coexisting medical complications. Unfortunately, the specific mechanism for this increased risk of stillbirth has yet to be identified.[43,44] Although the reason for this increased risk is poorly understood, hypotheses include poorly controlled undiagnosed diabetes mellitus, predisposition to fetal anomalies as well as increased risk of hypoxic-apneic episodes due to undiagnosed sleep apnea.[44,45] Some experts, therefore, suggest increased third trimester surveillance including initiation of antenatal fetal testing.[31]
It is important to monitor fetal growth as women with obesity are at increased risk for fetal macrosomia as well as fetal growth restriction. Serial growth ultrasounds as well a sonographic estimation of fetal weight near delivery are recommended to accurately plan delivery route. ACOG recommends counseling regarding the option for a scheduled cesarean delivery if the estimated fetal weight is greater than 4,500 grams at time of delivery in a woman with diabetes and 5,000 grams in a non-diabetic individual.[46] There is no specific recommendation with respect to route of delivery pertaining to BMI criteria. Close surveillance for preterm labor is suggested given the significantly increased risk for premature birth,[10] and antenatal steroids should be administered when the risk for preterm birth within seven days exists.[47,48]
Intrapartum
Labor and delivery poses unique challenges for the parturient with obesity and the obstetrical provider. Mothers with obesity are more likely to carry a pregnancy past their scheduled due date and often have indications for induction of labor.[49,50] This population is at increased risk of failed induction despite attempts at augmentation of labor with oxytocin.[51,52] This places them at increased need for cesarean delivery, and the inherent morbidities of a surgical delivery. These morbidities, including venous thromboembolism, gastric aspiration, anesthesia complications, pneumonia, wound infection and dehiscence, and others, are further complicated by maternal obesity with respect to risk. Women with obesity who undergo cesarean delivery are at increased risk for wound complications including infections and wound breakdown.[8,53] One study estimates the risk of cesarean delivery in the patient with obesity (BMI 30–34.9kg/m²) at 33.8 percent, compared with 20.7 percent in the non-obese control group. The same study showed that women with extreme obesity (BMI >35kg/m²) had a cesarean delivery rate of up to 50 percent,4 (see “cesarean section” in following section).
Anesthetic considerations
Parturients with obesity are at significantly greater risks for anesthesia related complications. Up to 75 percent of anesthesia-related maternal deaths are complicated by maternal obesity, the majority of which are related to the inability of obtaining an endotracheal airway,[54] thus emphasizing the benefit of regional anesthesia when possible. Anesthetic consultation should ideally be sought during the third trimester of pregnancy or upon admission to labor and delivery.[31] The anesthesiologist should be made aware of obesity-related comorbidities and the presence of preeclampsia, as airway edema may further compromise successful intubation.[55] Experts suggest placement of an epidural catheter early in the labor process even if it is not yet necessary for pain control, so as to reduce the probability of need for general anesthesia should emergent delivery be required.[56–58] If general anesthesia is anticipated, then consideration for an “awake” intubation is appropriate. Also video laryngoscopes should be available. If providers and institutions find themselves without these resources, then maternal transport to a tertiary care center should be considered.[31] The environment that provides resources contributing to the greatest element of patient safety should be sought. Prior to intubation, preoxygenation is particularly important in this patient population. In the typical healthy nonobese patient it takes nine minutes for oxygen saturation to fall from 100 to 90 percent, while the patient with obesity reaches the same level of desaturation within three minutes. Oxygen desaturation may be even more drastic in individuals with extreme obesity.[59,60] Physiologic changes of pregnancy result in a 20-percent increase in oxygen consumption and a 20 to 30-percent decrease in functional residual lung capacity in pregnancy. This change is the result of an upward shift of the diaphragm as well as increases to the residual and expiratory reserve volumes.[61] Relaxation of the lower esophageal sphincter and increased intra-abdominal pressure make aspiration of gastric contents a genuine threat during pregnancy. Aspiration is compounded by both the physiological changes of pregnancy as well as obesity. Therefore, it is recommended to give 30mL of nonparticulate antacid, such as sodium citrate, to decrease gastric content acidity. Also, an H2 blocker can be given as well as a prokinetic agent such as metoclopramide.[57]
Antibiotics
Women with obesity undergoing cesarean section should receive higher doses of prophylactic antibiotics than women of normal weight.[62] In general and specifically related to cesarean section, preoperative antibiotic administration has been shown to decrease the risk of infectious morbidity. Patients undergoing bariatric surgery were studied to evaluate efficacy of antibiotic dosage among individuals with extreme obesity . The evidence showed that therapeutic tissue levels were achieved in only 10 to 48 percent of cases. Those patients with BMI greater than 60kg/m² had the lowest levels of adequate antibiotics while those with BMI 40 to 49.9kg/m² achieved therapeutic levels in only about 48 percent of cases.[63] Guidelines established for 2013 by the American Society of Health-system Pharmacists, the Infectious Disease Society of America, the Surgical Infection Society, and the Society for Healthcare Epidemiology of America recommend cefazolin 2 grams for women less than 120kg undergoing cesarean delivery and 3 grams for those greater than 120kg.[64] If the patient has a history of severe penicillin allergy then the alternative regimen of clindamycin 900mg plus gentamicin 5mg/kg of actual body weight should be considered. If actual body weight is greater than 20 percent more than ideal body weight then dosage should be adjusted accordingly.[64]
Venous thromboembolism
Intrapartum risk of thromboembolic disease is increased in pregnancy, and further increased by obesity as well as cesarean delivery. Most experts recommend a minimum of intermittent pneumatic compression devices that are able to accommodate large legs. In the Cochrane review, metanalysis failed to show evidence for universal prophylaxis. Despite this lack of hard evidence, experts generally recommend pharmacologic thromboprophylaxis in the postpartum patient with obesity until they are fully ambulatory.[13,65–70] Recommendations from the Society for Maternal-Fetal Medicine are to consider low molecular weight heparin or unfractionated heparin for pharmacologic thromboprophylaxis in the postpartum patient with obesity after cesarean delivery.[62] Resumption of prophylactic anticoagulation should be held for 12 hours after cesarean delivery or removal of an epidural catheter, whichever is later.[62,71]
Vaginal birth after cesarean delivery
Vaginal birth after cesarean delivery (VBAC) has poor success in patients with obesity . In one large prospective multicenter study, nonobese women had a VBAC failure rate of 15 percent compared to 30 percent for women with obesity (BMI 25.0–29.9kg/m²) and 39 percent for women with morbid obesity (BMI >40kg/m²). The population with obesity also had increased rates of uterine scar dehiscence (1.4–2.1% compared to 0.9% in the nonobese population).[72] In those patients weighing over 300 lbs, VBAC success rates are noted to be as low as 10 percent.[73] Not only were they at increased risk of failure, but the higher rate of complications (risk of infection, uterine rupture, hemorrhage requiring blood transfusion) related to cesarean delivery after a failed trial of labor make it crucial that providers adequately counsel patients with obesity about the low likelihood of VBAC success, and the option of scheduled repeat cesarean section.[73]
Cesarean Delivery
Surgical approach to the patient with obesity undergoing cesarean delivery should be individualized based on each patient’s unique body habitus. It is important to note that in individuals with obesity , particularly those with an “apron-like” pannus of adipose tissue, the umbilicus is a poor landmark to identify pelvic organs. In these women the pubic symphysis and iliac crests are more reliable and consistent marks,[74] and should be examined and palpated in planning a successful surgical approach. In the nonobese patient, a pfannenstiel incision is generally made two finger breadths above the pubic symphisis. Even in individuals with extreme obesity, the adipose tissue in this location is not particularly thick, making it an option for incision placement; however the size, location, and retractability of the panniculus may limit its utility. Montgomery straps or an improvised approach using elastoplast tape to retract the pannus cephalad, may allow for improved access to the suprapubic region for pfannensteil incision placement. Care must be taken with cephalad pannus retraction as this potentially can exacerbate cardiorespiratory compromise due to excessive weight displacement onto the thorax.[75] One must also exercise care in not making the incision too low if the pannus is left in situ, as the incision could potentially be carried down into the subcutaneous tissue and then through the other side of the pannus, without entering the peritoneal cavity. Postoperative care of a pfannensteil incision among the patient with obesity must be attended to carefully and allow for the area to be kept clean and dry given that it is a relatively warm and moist environment. The transverse periumbilical incision may be considered, particularly for those women who are over 400 Lbs. as it provides the strength of a transverse repair without burying the incision under a large panniculus.[76] One disadvantage to this approach, however, is that exposure to the lower uterine segment can be suboptimal and require a vertical hysterotomy thus increasing risk of blood loss and uterine rupture during subsequent pregnancy.[65] Also, subcutaneous tissue will be at its greatest depth in this region, and care must be taken during subcutaneous tissue dissection, as large caliber veins are commonly noted within this fatty layer.[65]
Fascial closure is typically accomplished with delayed absorbable or nonabsorbable suture and utilizes the Smead-Jones technique (far-far-near-near) or an equivalent method that incorporates mass closure if a vertical incision was utilized. We tend to avoid placement of a vertical incision if possible, as they have been shown to be complicated by wound dehiscence and infection more frequently than transverse skin incisions.[77–78] Randomized trials have shown that closure of the subcutaneous space with a depth of greater than 2cm, reduces the risk of wound disruption by up to 33 percent.[79]
Subcutaneous drains have been shown in randomized controlled trials to increase rates of wound complications and are therefore not generally recommended.[80] Skin closure may be accomplished with either subcuticular stitches or staples. Studies in the general population have failed to prove one method superior to the other but they have not been compared directly in the population with obesity undergoing cesarean delivery.[62,81,82]
Hospital equipment capable of providing service for the patient with obesity must be available at hospitals where such patients are expected. Weight capacity of a standard hospital bed is generally 350 to 400 lbs., while specialized bariatric beds can accomidate 600 to 1,000 lbs.[62] Standard wheelchairs may also be insufficient for the patient with obesity and bariatric options should be available.
Postoperatively, additional assistance in moving the patient is often required in order to safely transfer an anesthetized patient from the operating table to a recovery bed. In addition to the above mentioned considerations, specialized surgical equipment, such as long instruments, deeper retractors, and the alexis-o retractor, should be immediately available to the operating suite.[62]
Postpartum
The postpartum period continues to infer risk to the recently delivered patient with obesity. As mentioned previously, obesity increases the risk for development of endomyometrisis, wound infection and venous thromboembolism among other potential complications.[4,5,7,8] Interventions to reduce these risks have also been discussed previously (see sections on antibiotics and venous thromboembolism). Postpartum evaluation 1 to 2 weeks to assess wound healing and resolution of pregnancy related complications, including hypertension, should be encouraged.
Postpartum depression has been shown to be positively correlated with BMI and in cases of extreme obesity, present in up to 40 percent of patients.[83] Patients should be made aware of the signs of postpartum depression and be provided with resources for adequate treatment should symptoms arise. Screening for postpartum depression should be accomplished using a proven depression screening method such as the Edinburgh Depression Scale.
Maternal weight retention postpartum will place the patient at increased risk for long-term health risks, including cardiovascular and metabolic diseases.[84] Weight loss in the postpartum period can be enhanced by resumption of physical activity and breastfeeding.[85] Breast feeding has long-known health benefits for the neonate, but it should be made known that maternal benefits including weight loss may also occur.[85]
Increased prevelance of gestational diabetes means that these patients should be counseled on the importance of appropriate follow up to screen for pregestational diabetes at the six-week postpartum checkup. Patients with a history of gestational diabetes have a seven-fold increased risk of development of diabetes later in life.[86] The Fifth International Workshop on Gestational Diabetes Mellitus recommends that women undergo a 75 gram, two-hour oral glucose tolerance test in the time period of 6 to 12 weeks postpartum.[87,88]
As discussed previously, adequate counseling on the relationship of obesity and maternal and fetal risk in subsequent pregnancies should be reviewed in great detail during the postpartum visit. It is precisely because of this increased risk that family planning be reviewed and course of action made in accordance with the patient’s long-term family planning goals. Providers must take advantage of the six-week postpartum visit to provide additional preconception counseling as in many cases the next time the patient returns to the office, the reason could be to initiate prenatal care once again.
Summary
Given the increased risks for a multitude of adverse pregnancy outcomes when pregnancy is complicated by obesity, women should be encouraged to achieve a normal BMI prior to conception. The obese gravida should be managed as a “high-risk” pregnancy, and surveillance heightened with interventions as outlined here. Hospitals should have proper bariatric certified equipment and other specialized equipment to care for the potential complications of obesity and pregnancy. Transfer of care to a tertiary care center should be considered on an individual basis, when degree of obesity, complicating comorbidities, and/or providers with limited provider experience creates the potential for a diminishment of patient safety.
References
1. Centers for Disease Control. Overweight and Obesity. http://www.cdc.gov/obesity. Accessed September 15, 2013.
2. Weight Control Information Network. Overweight and Obesity Statistics. http://www.win.niddk.nih.gov/statistics/index.htm. September 15, 2013.
3. Pi-Sunyer FX, Becker DM, Bouchard C, et al. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults. June 1998. http://www.nhlbi.nih.gov/guidelines/obesity/ob_gdlns.pdf. #4083. November 24, 2013.
4. Weiss JL1, Malone FD, Emig D, et al. Obesity, obstetric complications and cesarean delivery rate: a population-based screening study. Am J Obstet Gynecol. 2004;190(4):1091–1097.
5. Cedergren MI. Maternal morbid obesity and risk of adverse pregnancy outcome. Obstet Gynecol. 2004;103(2):219–224.
6. Chu SY1, Kim SY, Schmid CH, et al. Maternal obesity and risk of cesarean delivery: a meta-analysis. Obes Rev. 2007;8(5):385–394.
7. Perlow JH1, Morgan MA. Massive maternal obesity and perioperative cesarean morbidity. Am J Obstet Gynecol. 1994;170(2):560–565.
8. Myles TD, Gooch J, Santolaya J. Obesity as an independant risk factor for infectious morbidity in patients in patients who undergo cesarean delivery. Obstet Gynecol. 2002;100(5 Pt 1):959–964.
9. Hediger ML, Overpeck MD, McGlynn A, et al. Growth and fatness at three to six years of age of children born small or large-for-gestaional age. Hediger ML, Overpeck MD, McGlynn A, et al. Pediatrics. 1999;104(3):e33.
10. Cnattingius S, Villamor E, Johansson S, Maternal obesity and risk of preterm delivery. JAMA. 2013;309(22):2362–2370.
11. Flick A, Artel R. Obesity and weight gain in pregnancy. Contemporary Ob/Gyn. 2013; 58(1):7.
12. Romen Y, Masaki DI, Mittelmark RA. Physiologic and endocrine adjustments to pregnancy. In: Mittelmark RA, Wiswell RA, Drinkwater BL, editors. Exercise in Pregnancy. Williams & Wilkins: Baltimore, MD; 1991.
13. ACOG committee opinion no. 549: obesity in pregnancy. American College of Obstetricians and Gynecologists (ACOG). Obstet Gynecol. 2013;121(1):213–217.
14. Getahun D, Ananth CV, Oyelese Y, et al. Primary preeclampsia in the second pregnancy: effects of changes in prepregnancy body mass index between pregnancies. Obstet Gynecol. 2007;110(6):1319–1325.
15. Getahun D, Ananth CV, Peltier MR, Salihu HM, Scorza WE. Changes in prepregnancy body mass index between the first and second pregnancies and risk of large-for-gestational-age birth. Am J Obstet Gynecol. 2007 Jun;196(6):530.e1-8.
16. Getahun D, Kaminsky LM, Elsasser DA, Kirby RS, Ananth CV, Vintzileos AM. Changes in prepregnancy body mass index between pregnancies and risk of primary cesarean delivery. Am J Obstet Gynecol. 2007 Oct;197(4):376.e1-7.
17. Must A, Spadano J, Coakley EH, Field AE, Colditz G, Dietz WH. The disease burden associated with overweight and obesity. JAMA. 1999 Oct 27;282(16):1523-9.
18. Wang JX, Davies M, Norman RJ. Body mass and probability of pregnancy during assisted reproduction treatment: retrospective study. BMJ. 2000 Nov 25;321(7272):1320-1.
19. ACOG practice bulletin no. 105: bariatric surgery and pregnancy. American College of Obstetricians and Gynecologists (ACOG). Obstet Gynecol. 2009 Jun;113(6):1405-13.
20. Skull AJ, Slater GH, Duncombe JE, Fielding GA. Laparoscopic adjustable banding in pregnancy: safety, patient tolerance and effect on obesity-related pregnancy outcomes. Obes Surg. 2004 Feb;14(2):230-5.
21. Moore KA, Ouyang DW, Whang EE.Maternal and fetal deaths after gastric bypass surgery for morbid obesity. N Engl J Med. 2004 Aug 12;351(7):721-2.
22. Loar PV 3rd, Sanchez-Ramos L, Kaunitz AM et al. Maternal death caused by midgut volvulus after bariatric surgery. Am J Obstet Gynecol. 2005 Nov;193(5):1748-9.
23. Tohamy AE, Eid GM. Laparoscopic reduction of small bowel intussusception in a 33-week pregnant gastric bypass patient: surgical technique and review of literature. Surg Obes Relat Dis. 2009 Jan-Feb;5(1):111-5.
24. Wax JR, Wolff R, Cobean R et al. Intussusception complicating pregnancy following laparoscopic Roux-en-Y gastric bypass.Obes Surg. 2007 Jul;17(7):977-9.
25. Gastrointestinal hemorrhage during pregnancy in a patient with a history of vertical-banded gastroplasty. Ramirez MM, Turrentine MA. 1630, s.l. : Am J Obstet Gynecol, 1995, Vol. 173.
26. Ouyang, David W. Fertility and pregnancy after bariatric surgery. UpToDate. [Online] August 7, 2013. [Cited: September 27, 2013.] http://www.uptodate.com/contents/fertility-and-pregnancy-after-bariatric-surgery.
27. Department of Health and Human Services. What is the purpose of prenatal & pregnancy care? Eunice Kennedy Shriver National Institute of Child Health and Human Development. National Institute of Health. http://www.nichd.nih.gov/health/topics/obstetrics/conditioninfo/Pages/purpose.aspx#f1. Accessed February 27, 2013.
28. Osterman M.H.S., Michelle JK. Martin MPH, Joyce A. Mathews M.S., T.J. Hamilton PhD, Brady. National Vital Statistics Report: Expanded Data From the New Birth Certificate, 2008. Hyattsville : Center for Disease Control, 2011.
29. Zain MM, Norman RJ. Impact of obesity on female fertility and fertility treatment. Womens Health (Lond Engl). 2008 Mar;4(2):183-94.
30. MetwallyM, Li TC, Ledger WL. The impact of obesity on female reproductive function. Obes Rev. 2007 Nov;8(6):515-23. Epub 2007 Sep 14.
31. Gunatilake RP, Perlow JH. Obesity and pregnancy: clinical management of the obese gravida. Am J Obstet Gynecol. 2011 Feb;204(2):106-19.
32. Avelar E, Cloward TV, Walker JM, et al. Left ventricular hypertrophy in severe obesity: interactions among blood pressure, nocturnal hypoxemia and body mass. Hypertension. 2007 Jan;49(1):34-9. Epub 2006 Nov 27.
33. Owan T, Litwin SE. Is there cardiomyopathy of obesity. Curr Heart Fail Rep. 2007 Dec;4(4):221-8.
34. Duley L, Henderson-Smart DJ, Meher S, King JF. Antiplatelet agents for preventing pre-eclampsia and its complications. Cochrane Database Syst Rev. 2007 Apr 18;(2):CD004659.
35. Rasmussen SA, Chu SY, Kim SY, Schmid CH, Lau J. Maternal obesity and risk of neural tube defects: a metaanalysis. Am J Obstet Gynecol. 2008 Jun;198(6):611-9.
36. Werler MM, Louik C, Shapiro S, Mitchell AA. Prepregnant weight in relation to risk of neural tube defects. JAMA. 1996 Apr 10;275(14):1089-92.
10;275(14):1089-92.
37. Stothard KJ, Tennant PW, Bell R, Rankin J. Maternal overweight and obesity and the risk of congenital anomalies: a systematic review and metaanalysis. JAMA. 2009 Feb 11;301(6):636-50.
38. Watkins ML, Rasmussen SA, Honein MA, Botto LD, Moore CA. Maternal obesity and risk for birth defects. Pediatrics. 2003 May;111(5 Pt 2):1152-8.
39. Shaw GM, Velie EM, Schaffer D. Risk of neural tube defect-affected pregnancies among obese women. JAMA. 1996 Apr 10;275(14):1093-6.
40. Dashe JS1, McIntire DD, Twickler DM. Maternal obesity limits the ultrasound evaluation of fetal anatomy. J Ultrasound Med. 2009 Aug;28(8):1025-30.
41. Practice Bulletin no. 134: Fetal Growth Restriction. American College of Obstetricians and Gynecologists, ACOG. 1122-33, s.l. : Obstet Gynecol, 2013, Vol. 121.
42. ACOG practice bulletin no. 77. Screening for fetal chromosomal abnormalities. American College of Obestricians and Gynecologists (ACOG). Obstet Gynecol. 2007 Jan;109(1):217-27.
43. Kristensen J, Vestergaard M, Wisborg K, Kesmodel U, Secher NJ. Pre-pregnancy weight and the risk of stillbirth and neonatal death. BJOG. 2005 Apr;112(4):403-8.
44. Fretts, RC. Etiology and prevention of stillbirth. Am J Obstet Gynecol. 2005 Dec;193(6):1923-35.
45. Maasilta P, Bachour A, Teramo K, Polo O, Laitinen LA. Sleep-related disordered breathing during pregnancy in obese women. Chest. 2001 Nov;120(5):1448-54.
46. ACOG practice bulletin no. 22: fetal macrosomia. American College of Obstetricians and Gynecologists Obstet Gynecol, 2000. Obstet Gynecol. 2013;96(5):213–217.
47. Roberts D, Dalziel S. Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth. Cochrane Database Syst Rev. 2006 Jul 19;(3):CD004454.
48. ACOG committee opinion no. 475: Antenatal corticoseroid therapy for fetal maturation. American College of Obstetricians and Gynecologists (ACOG). Obstet Gynecol. 2011 Feb;117(2 Pt 1):422-4.
49. Denison FC, Price J, Graham C, Wild S, Liston WA. Maternal obesity, length of gestation, risk of postdates pregnancy and spontaneous onset of labour at term. BJOG. 2008 May;115(6):720-5.
50. Stotland NE, Washington AE, Caughy AB. Prepregnancy body mass index and the length of gestation at term. Am J Obstet Gynecol. 2007 Oct;197(4):378.e1-5.
51. Pevzner L, Powers L, Rayburn WF, Rumney P, Wing DA. Effects of maternal obesity on duration and outcomes of prostaglandin cervical ripening and labor induction. Obstet Gynecol. 2009 Dec;114(6):1315-21.
52. Cedergren, MI. Non-elective cesarean delivery due to ineffective uterine contractility or due to obstructed labour in relation to maternal body mass index. Eur J Obstet Gynecol Reprod Biol. 2009 Aug;145(2):163-6.
53. Larson TB, Sorensen HT, Gislum M, Johnsen SP. Maternal smoking, obesity and risk of venous thromboembolism during pregnancy and the puerperium: a population-based nested case-control study. Thromb Res. 2007;120(4):505-9. Epub 2007 Jan 25.
54. Vellejo MC. Anesthetic management of the morbidly obese parturient. Curr Opin Anaesthesiol. 2007 Jun;20(3):175-80.
55. Perlow JH, Kirz DS. Severe preeclampsia presenting as dysphonia secondary to uvular edema. A case report. J Reprod Med. 1990 Nov;35(11):1059-62.
56. Hood DD, Dewan DM. Anesthetic and obstetric outcome in morbidly obese patients. Anesthesiology. 1993 Dec;79(6):1210-8.
57. Soens MA, Birnbach DJ, Ranasinghe JS, van Zundert A. Obstetric anesthesia for the obese patient: an ounce of prevention is worth more than a pound of treatment. Acta Anaesthesiol Scand. 2008 Jan;52(1):6-19.
58. The effect of maternal obesity on labour and labour pain. Ranta P, Jouppila P, Spalding M, Jouppila R. 322-6, s.l. : Anaesthesia, 1995, Vol. 50.
59. Dixon BJ, Dixon JB, Carden JR, et al. Preoxygenation is more effective in the 25 degrees head-up position than in the supine position in severely obese patients: a randomized controlled study. Anesthesiology. 2005 Jun;102(6):1110-5; discussion 5A..
60. Altermatt FR, Munoz HR, Delfino AE, Cortinez LI. Pre-oxygenation in the obese patient: effects of position on tolerance to apnea. Br J Anaesth. 2005 Nov;95(5):706-9. Epub 2005 Sep 2.
61. Maternal respiratory changes during pregnancy and parturition. Bonica, JJ. 2, s.l. : Clin Anesth, 1974, Vol. 10. 1.
62. Johnson D, Society for Maternal-Fetal Medicine (SMFM). Management of cesarean delivery in the morbidly obese woman. Contemporary Ob/Gyn.
63. Perioperative antibiotic prophylaxis in the gastric bypass patient: do we achieve therapeutic levels? Edmiston CE, Krepel C, Kelly H, et al. 738-47, s.l. : Surgery, 2004, Vol. 136.
64. Clinical practice guidelines for antimicrobial prophylaxis in surgery. Bratzler DW, Dellinger EP, Olsen KM, et al. 195, s.l. : Am J Health Syst Pharm, 2013, Vol. 70.
65. Porreco, Richard P. Cesarean delivery of the obese woman. Uptodate. [Online] July 1, 2013. [Cited: September 27, 2013.] http://www.uptodate.com/contents/cesarean-delivery-of-the-obese-woman.
66. Pregnancy-associated thrombosis. James AH. 85, s.l. : Hematology Am Soc Hematol Educ Program, 2009, Vol. 277.
67. Venous thromboembolism, thrombophilia, antithrombotic therapy and pregnancy. Bates SM, Greer IA, Pabinger I, Sofaer S, Hirsh J. 844S-86S, s.l. : American college of Chest Physicians Evidence Based Clinical Practice Guidelines, 8th ed, 2008, Vol. 133.
68. Prevention of venous thromboembolism in pregnancy. Greer IA. 261-78, s.l. : Best Pract Res Clin Haematol, 2003, Vol. 16.
69. Venous thromboembolic disease and pregnancy: a review. Marik PE, Plante LA. 2025-33, s.l. : N Engl J Med, 2008, Vol. 359.
70. Prophylaxis for venous thromboembolic disease in pregnancy and the early postnatal period. Tooher R, Gates S, Dowswell T, Davis LJ. s.l. : The Cochrane library, 2010, Vol. 5. CD001689.
71. Panniculectomy at the time of gynecologic surgery in morbidly obese patients. Hopkins MP, Shriner AM, Parker MG, Scott L. 1502-5, s.l. : Am J Obstet Gynecol, 2000, Vol. 182.
72. Deciding on route of delivery for obese women with a prior cesarean delivery. Edwards RK, Harnsberger DS, Johnson IM, Treloar RW, Cruz AC. 385-94, s.l. : Am J Obstet Gynecol, 2003, Vol. 189.
73. Vaginal birth after cesarean section versus elective repeat cesarean delivery: weight-based outcomes. Carroll CS Sr, Magann EF, Chauhan SP, Klauser CK, Morrison JC. s.l. : Am J Obstet Gynecol, 2003, Vol. 188. 1516-22.
74. Cesarean section in morbidly obese women: supra or subumbilical transverse incision. Tixier H, Thouvenot S, Coulange L, et al. 1049, s.l. : Acta Obstet Gynecol Scand, 2009, Vol. 88.
75. Preventing a surgical complication during cesarean delivery in a morbidly obese patient: a simple apparatus to retract the abdominal panniculus. Viegas CM, Viegas OA. 52, s.l. : MedGenMed, 2006, Vol. 8.
76. Cesarean birth in the morbidly obese woman: a report of 3 cases. Porreco RP, Adelberg AM, Lindsay LG, Holdt DG. 231, s.l. : J Reprod Med, 2007, Vol. 52.
77. Vertical skin incisions and wound complications in the obese parturient. Wall PD, Deucy EE, Glantz JC, Pressman EK. s.l. : Obstet Gynecol, 2003, Vol. 102. 952-956.
78. Operative considerations in the obese pregnant patient. Gross, TL. 411, s.l. : Clin Perinatol, 1983, Vol. 10.
79. Suture closure of subcutaneous fat and wound disruption after cesarean delivery: a meta-analysis. Chelmow D, Rodriguez EJ, Sabatini MM. 974, s.l. : Obstet Gynecol, 2004, Vol. 103.
80. Subcutaneous tissue reapproximation, alone or in combination with a drain, in obese women undergoing cesarean delivery. Ramsey PS, White AM, Guinn DA, et al. 967, s.l. : Obstet Gynecol, 2005, Vol. 105.
81. Techniques and materials for skin closure in cesarean section. Mackeen AD, Berghella V, Larsen ML. s.l. : Cochrane Database Syst Rev, 2012, Vol. 9. CD003577.
82. Staples compared with subcuticular suture for skin closure after cesarean delivery. Nuthalapaty FS, Kuper SG, Higdon HL 3rd. 166, s.l. : Obstet Gynecol, 2011, Vol. 118.
83. The association between prepregnancy obesity and screening positive for postpartum depression. LaCoursiere DY, Barrett-Connor E, O’Hara MW, Hutton A, Varner MW. 1011-8, s.l. : BJOG, 2010, Vol. 117.
84. Excessive gestational weight gain and postpartum weight retention among obese women. Vesco KK< Dietz PM, Rizzo J, et al. 1069-75, s.l. : Obstet Gynecol, 2009, Vol. 114.
85. Breastfeeding reduces postpartum weight retention. Baker JL, Gamborg M, Heitman BL, Lissner L, Sorensin TI, Rasmussen KM. 1543-51, s.l. : Am J Clin Nutr, 2008, Vol. 88.
86. Type 2 diabetes mellitus after gestational diabetes: a systematic review and meta-analysis. Bellamy L, Casaa JP, Hingorani AD, Williams D. 1773-9, s.l. : Lancet, 2009, Vol. 373.
87. Summary and recommendations of the Fifth International Workshop-Conference on Gestational Diabetes Mellitus. Metzger BE, Buchanan TA, Coustan DR, de Leiva A, Hadden DR, et al. S251-60, s.l. : Diabetes Care, 2007, Vol. 30.
88. Practice Bulletin no. 137, Gestational diabetes mellitus. American College of Obestricians and Gynecologists. 406-16, s.l. : Obstet Gynecol, 2013, Vol. 122.
89. Obesity as an independant risk factor for infectious morbidity in patients who undergo cesarean delivery. TD Myles, J Gooch, J Santolaya. 100:959-64, s.l. : Obstet Gynecol, 2002.
Category: Past Articles, Review
Subscribe
If you enjoyed this article, subscribe to receive more just like it.
