Catherine Takacs Witkop1
(1)
Department of Obstetrics/Gynecology and Preventive Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
Catherine Takacs Witkop
Email: cwitkop@gmail.com
Abstract
Overweight and obesity are associated with multiple maternal and fetal complications, including gestational diabetes mellitus, hypertensive disorders of pregnancy, macrosomia (infant weighing more than 4,000 g), and cesarean delivery. The preconception period is a critical time frame to address overweight and obesity in reproductive-aged women. Preconception care should include education about the effect of obesity on pregnancy outcomes, long-term health of the offspring, clinical evaluation for comorbid conditions, assessment of the patient’s readiness for change, and guidance on safe and effective interventions to achieve a healthy weight prior to conception. Current gaps in our knowledge include the identification of the most effective lifestyle strategies to promote a healthy weight prior to pregnancy and the development of policies to improve the dissemination of patient-centered preconception care.
Keywords
Preconception careOverweightObesePregnancy outcomesLifestyle modificationBehavioral counseling
I view preconception care as empowering women, to give them control over their pregnancy outcomes. Peter M. Bernstein, Medscape July 8, 2010
Key Points
· All reproductive-aged women should be screened for obesity by providers using body mass index (BMI).
· Providing overweight and obese women with evidence-based lifestyle modifications can help to improve health status prior to conception.
· Screening for obesity-related conditions including diabetes and dyslipidemia is an important step to improve a woman’s health before conception.
· Motivational interviewing, guidance on nutrition and physical activity, and patient activation tools during the preconception phase help women achieve a healthy lifestyle before pregnancy.
Introduction
Transitioning women from the preconception phase to the pregnancy phase of their lives has been an incredible challenge for providers and public health officials. The life-course model, developed by Lu and Halfon, focuses on the medical and psychosocial factors that affect a woman’s health from birth until the time she conceives. The preconception period is an “important teachable moment” and represents a unique opportunity [1] to educate overweight and obese women about achieving a healthy weight before conception. Preconception care is defined as a set of interventions that aim to identify and modify behavioral and social risks to a woman’s health or pregnancy outcomes through prevention and management [2]. If a woman is overweight or obese and contemplating pregnancy, it is incumbent upon her provider to counsel her about the potential complications of obesity on pregnancy outcomes and the health of her offspring. Such efforts can improve maternal health before pregnancy, reduce infant mortality, and lower the risk of metabolic alterations or fetal programming that can predispose to childhood obesity. In this chapter, we summarize the key clinical and behavioral components of counseling for obesity during the preconception period. These components include (1) discussion of maternal and fetal complications, (2) assessment of readiness for behavioral change, (3) guidance on safe and effective lifestyle modifications that can help women achieve weight loss prior to pregnancy, and (4) provision of information on what interventions may be necessary during pregnancy if she is overweight or obese at the time of conception. Additionally, this chapter provides insight on clinical conditions that commonly occur in the women who are overweight or obese at the time of conception, including bariatric surgery, gestational diabetes mellitus, and hypertension. The impact of obesity in polycystic ovarian syndrome and subfertility is also discussed.
Potential Risks for the Overweight or Obese Pregnant Woman
Women who are classified as obese (Table 3.1) are at increased risk for maternal and fetal complications during pregnancy [3]. Although statistics alone are not typically enough to motivate individuals to achieve significant behavioral change, it is important for women to receive accurate and timely information during the preconception visit. In a large prospective multicenter study, obese women were 2.5 times more likely than women with BMI under 30 to develop gestational hypertension; morbidly obese women were 3.2 times more likely [4, 5]. Obese and morbidly obese women were also 1.6 and 3.3 times, respectively, more likely to develop preeclampsia than their counterparts who were of normal weight [5]. Obese women are also at increased risk for gestational diabetes, and when obese women develop gestational diabetes, they are at increased risk for additional complications. For these reasons, women with morbid obesity are among those considered high enough risk to justify early screening for gestational diabetes (other risk factors include strong family history of type 2 diabetes, history of GDM, impaired glucose metabolism, or glucosuria) [6]. They should be screened as early as feasible and should be repeated at 24–28 weeks if the first screen is negative. Obese women are also at increased risk of labor complications, including macrosomia and cesarean delivery, which require ongoing conservations with their clinicians and shared decision-making in planning for labor and delivery (Chap. 5).
Table 3.1
Institute of Medicine weight gain in pregnancy guidelines
|
Prepregnancy BMI |
BMI (kg/m2) |
Recommended total weight gain range (lb) |
Rates of weight gain (2nd and 3rd trimester) (mean range in lb/week) |
|
Underweight |
<18.5 |
28–40 |
1 (1–3) |
|
Normal weight |
18.5–24.9 |
25–35 |
1 (.8–1) |
|
Overweight |
25.0–29.9 |
15–25 |
0.6 (0.5–0.7) |
|
Obese (includes all classes) |
≥30.0 |
11–20 |
0.5 (0.4–0.6) |
From Rasmussen et al. [3]
Guidelines for Perinatal Care, issued by both the American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics (AAP), recommends that all health encounters during a woman’s reproductive years include counseling to improve future pregnancy outcomes [7]. The Centers for Disease Control and Prevention (CDC) recommends that all primary care clinicians integrate preconception counseling into every health-care encounter [8]. Given the fact that overweight and obesity can have such negative impacts on the health of a woman and her child, and understanding that about 50 % of pregnancies in the USA are unplanned, preconception care should occur during every visit with an overweight or obese woman.
Approaching the Patient Who Is Overweight or Obese
Because of the social stigma attached to overweight and obesity, diagnosis and discussion may need to be handled with greater tact than a discussion about hypertension, but it does need to happen. Much research has focused on the impact of using appropriate terminology when discussing overweight and obesity with patients [9]. What appears to be consistent is that women do not respond in a consistent way to descriptors of their weight. Using terminology that describes the impact of weight on health appears to be acceptable to patients, and this approach may be the most comfortable. In the end, however, as long as derogatory language is not used, any discussion is better than ignoring the topic altogether. Cultural competency must also play a role in the discussion of weight with patients. Different cultures have varying attitudes toward overweight, so the provider may be making recommendations that are counter to a patient’s perspective. Understanding the patient’s background, home environment, stressors, and socioeconomic status is important before the provider embarks on recommendations to change behavior.
Clinical Assessment at the Health Visit
Body Mass Index
BMI (Table 3.1) [3] should be calculated at each health visit and reviewed as a vital sign in the same fashion as blood pressure is addressed. BMI is calculated as
Electronic medical records can often be enabled to calculate BMI automatically when height and weight are entered. A standard workflow in which actual weight is measured at each visit and BMI is calculated ensures providers have this additional “vital sign.”
Waist Circumference and Waist to Hip Ratio
Because central or abdominal obesity is associated with cardiovascular disease and death, waist circumference or waist to hip ratio (WHR) can be another measure to include in a preconception visit [9]. There are no specific prenatal guidelines related to these other measures of adiposity. However, these measures can provide long-term guidance about the risk of diabetes and cardiovascular disease.
Type 2 Diabetes and Lipid Screening
Screening for diabetes and dyslipidemia can be considered for the overweight or obese woman. The diagnosis of type 2 diabetes is important for pregnancy care. Type 2 diabetes is associated with a threefold increase in the prevalence of birth defects, but this risk can be reduced with proper management of diabetes before conception [10, 11]. Hemoglobin A1C levels should be in the lower range of normal (<6.1 %) prior to conception [10]. If a woman is newly diagnosed during the preconception visit, she will need a comprehensive medical evaluation with a primary care clinician or endocrinologist and referred for ophthalmic evaluation. A lipid panel would be indicated if the diagnosis of diabetes is made and may also been performed in the overweight or obese woman without diabetes. While dyslipidemia may not change obstetrical management, medications for lipid management are contraindicated in women who are attempting pregnancy, those who are currently pregnant, and lactating women. Therefore, obese women with abnormal lipids will need to be aware of the contraindications of medical therapy during the preconception and perinatal periods.
Folic Acid Supplementation
All reproductive-aged women are encouraged to take a 4 mcg daily dose of folic acid before pregnancy and at least through the first 4 weeks of pregnancy. Women who are obese have been found to have an increased risk for neural tube defects compared to women in a normal BMI range [12], but studies have not clearly demonstrated that an increased dose of folic acid would be appropriate for this population. At the very least, educating the patient about this additional risk to her offspring as a result of maternal obesity might offer additional motivation to take the recommended dose of preconception folic acid and to achieve a healthy weight before conception.
Screening for Obesity in Adults
The US Preventive Services Task Force (USPSTF) recommends screening all adults for obesity and states that clinicians should offer or refer patients with a BMI of 30 mg/m2 or greater to intensive, multicomponent behavioral interventions [13]. The American College of Preventive Medicine (ACPM) has also issued a practice statement about recommended counseling for overweight adults. Like most other organizations, the ACPM does not endorse any specific behavioral therapy or pharmacotherapy, but instead recommends individualized programs based on the available evidence [14]. There are two components to successful behavioral interventions. The first is to understand the relative effectiveness of different programs and recommend the intervention most likely to be successful for a given patient. The second is to engage the patient in a manner that will most likely lead to an activated patient who is likely to change her behavior.
Interventions for Lifestyle Modifications
Interventions for lifestyle modification have been shown time and again to be successful in reaching clinically relevant outcomes in diverse groups of women. For example, three large randomized controlled clinical trials of primary prevention of type 2 diabetes in three different countries have all demonstrated that maintenance of 3–5 kg (7–10 lb) of weight loss through diet and physical activity reduced the incidence of type 2 diabetes in high-risk individuals by 40–60 % over 3–4 years [15–17]. The largest study randomized over 3,000 patients to control, use of metformin, or lifestyle intervention (achieve and maintain 7 % or greater weight loss through a low-calorie, low-fat diet and at least 150 min of moderate physical activity per week) [17]. Over 3 years, the lifestyle intervention group lost an average of 5.6 kg, and the incidence of diabetes was reduced by 58 % [17]. While the outcomes in these studies were focused on prevention of diabetes, they demonstrated that lifestyle modification was indeed a worthwhile intervention in high-risk women. In a systematic review, Powell et al. reviewed and identified nine lifestyle modification trials. In the successful trials, weekly interventions resulted in the greatest weight reduction among participants, but after the initial intensive phase, monthly or bimonthly contact appeared to maintain 60–80 % of the initial weight loss [18].
Table 3.2
Applying the transtheoretical model (TTM)
|
Stage of change |
Description of patient |
Ways to assist patient |
|
Precontemplation |
No plans to change behavior(s) |
Motivational interviewing (can be used throughout) |
|
Does not believe behavior leads to adverse health outcomes |
Ask patient’s permission to discuss behavior/issues |
|
|
Contemplation |
May begin to understand relationship between behavior and adverse consequences on her health |
Ensure patient has knowledge and skills to change behavior |
|
Address doubts in self-efficacy |
||
|
Preparation |
Commits to behavior change |
Encourage family/friend involvement |
|
Makes concrete, actionable plans |
Help her recognize potential obstacles |
|
|
Advise her that relapses may occur |
||
|
Action |
Makes change in lifestyle or acquires healthy new behaviors |
Provide encouragement |
|
If relapse, identify ways to reduce risk of future relapse (avoid unhealthy triggers) |
||
|
Maintenance |
Continues to implement lifestyle change |
Ongoing evaluation, though less frequent |
|
Works to prevent relapse |
Provide encouragement |
|
|
Demonstrate empathy |
Modified from Prochaska and Velicer [20]
The evidence does demonstrate that lifestyle modification works, but it is certainly not without significant challenges. It is important, therefore, to utilize tools that have been demonstrated to facilitate behavioral change. Understanding models of behavior change and implementing patient activation tools can help women’s health providers as they care for overweight and obese women.
Models of Behavioral Change
Providers of women’s health care can apply social cognitive theory (SCT) to behavioral change counseling. SCT has been employed as the theoretical basis for a multitude of behavioral interventions. It supposes that three factors—environment, person, and behavior—interact and a change in one affects the other two [19]. A provider may be limited in the ability to alter the patient’s physical or social environment, but can make recommendations on how the patient can modify her surroundings or with whom she interacts. The “person” variables include behavioral capability (knowledge and skills to engage in the behavior), outcomes expectancies, observational learning, and perceived self-efficacy. Having the patient set realistic weight loss goals can increase perceived self-efficacy early on in the process. The transtheoretical model is the foundation of many of the behavioral interventions used in clinical medicine, and it assumes that all individuals transition through five stages of change in the process of altering a 'font-size:13.5pt;font-family:"Times New Roman",serif; color:blue'>3.2) [20]. These models are important and useful, but successful behavioral change also requires activated patients. Motivational interviewing is one tool to achieve that goal.
Motivational Interviewing
The goal of motivational interviewing (MI), first described by William Miller in 1983, is to use reflective listening and other tools to allow the patient to move through stages of change as described in the TTP [21]. The following are the key points of motivational interviewing [22]:
1.
2.
3.
4.
5.
6.
7.
The key skills can be summarized by the OARS acronym: (1) open-ended questions, (2) affirm, (3) reflect, and (4) summarize.
In a meta-analysis of 72 RCTs, motivational interviewing had a significant and clinically relevant effect in changing behaviors in about 75 % of the studies [23]. MI has been shown to be effective in studies of smoking cessation, unhealthy alcohol and drug use, and high-risk sexual behaviors [24]. It has also been studied in overweight and obesity. In an observational study of 40 primary care physicians, examining 461 of their provider-patient encounters, investigators found that use of motivational interviewing techniques during recorded patient visits was associated with statistically significant increases in amount of weight lost 3 months after the encounter [25]. Such techniques included verbalizing an understanding of the patient’s perspective, understanding motivation or lack of motivation, helping patients to find their own solutions and their own internal motivation to change, and assuring the patient that he or she has freedom to change. Other behaviors consistent with MI included praising, collaborating, and evoking “change statements” from patients [25].
These studies are promising, but future studies evaluating the use of motivational interviewing and other techniques that actively engage patients are needed [26]. Training providers in the use of MI and other such patient activation techniques and studying the effects via prospective randomized controlled trials can help determine if such provider tools improve effectiveness of lifestyle modification counseling. ACOG has recommended that providers understand and utilize MI with their patients in the appropriate clinical settings [27]. Not only is MI effective in certain scenarios but it also is very likely to improve the patient-provider relationship and provide useful insight into a patient’s successes and obstacles related to behavioral change.
Providing Tools for Preconception Weight Loss in Clinical Practice
Successful weight loss programs include setting of goals, monitoring, modification of the environment, cognitive restructuring, and setting plans to avoid relapse [28]. Referring the patient for individual or small group behavioral treatment may be helpful to enforce the behavioral modification [29]. Modification of lifestyle typically includes change in diet and increase in physical activity. The basic principle of weight loss is that energy intake must be less than energy expenditure. Overall, consumption of approximately 500 fewer kcal per day will allow loss of about 1 lb (0.45 kg) per week. Weight loss goals need to be realistic, and the means by which a patient is planning on reaching those goals need to be feasible. Loss of 5–10 % of current body weight (or 2 BMI units) over 6 months is a reasonable goal. Involvement of a dietician has been shown to facilitate weight loss in the office setting, supporting the notion of the importance of knowledge and tools for any behavioral change [30]. Dietary counseling is time-consuming if done well, and obstetrics providers may not have the time in a preconception visit to do a thorough assessment of a patient’s food intake and make effective recommendations. The provider’s main goal in preconception counseling should be to help identify realistic goals for the patient and provide a referral to a dietician to work through the details necessary to realize those goals. Another option that would likely ease the burden on the patient would be to provide nutritional guidance within the office setting. Having personnel on staff who fully realize the importance of a multidisciplinary approach to health and diet can lead to greater success for patients.
Low-fat diets traditionally restrict dietary fat intake to less than 30 % of total calories, and very-low-fat diets restrict to less than 15 % of total calories from fat. Weight loss does occur with low-fat diets, but very-low-fat diets may be difficult to maintain. In most studies, low-carbohydrate diets have demonstrated more weight loss than low-fat diets, at least in the first 12 months [29]. One potential side effect may be an increase in LDL cholesterol, which in the population of overweight or obese patients could be detrimental in the long run. Other commercial diets are also popular. Two recent randomized controlled trials comparing several different commercial diets found similar weight loss within the first 6–12 months in all diets [31, 32].
A large meta-analysis demonstrated that increases in physical activity combined with caloric restriction result in greater weight reduction and fat mass versus lean mass balance than either alone [33]. Physical activity in particular does rely heavily on environmental factors. Many women, with one or more jobs, children, and other life stressors, will find it challenging to fit in physical activity. Furthermore, many women live in areas where it may not be safe to exercise outside and may not have access to other exercise options. Again, motivational interviewing may be beneficial in identifying the barriers to increased physical activity and some of the patient’s own feelings about exercise. Without identifying and addressing both personal and environmental factors that are playing a role in a sedentary lifestyle, the provider will not be able to adequately promote behavior change.
Depending on a woman’s readiness for change, the provider may want to recommend delaying pregnancy until the woman can achieve a healthy weight. If she is not using effective contraception, the provider should recommend contraceptive options that will not make weight loss more difficult and that are easily reversible when pregnancy is desired. One type of contraception that may be less desirable is depot medroxyprogesterone acetate (DMPA) which could result in weight gain and may result in longer time to ovulation when conception is desired. Pharmaceutical management of obesity is outside the scope of this chapter, but lifestyle modification is also critical to the success of patients who are undergoing such treatment.
Bariatric Surgery
Bariatric surgery may be recommended for women with BMI of 40 kg/m2 and above or for women with BMI over 35 kg/m2 when comorbidities (such as diabetes, coronary artery disease, or severe sleep apnea) are present [34]. In general, women who undergo bariatric surgery demonstrate improvement in measures related to medical comorbidities as well as quality of life. Providers should counsel patients to avoid pregnancy for at least 12–18 months after surgery, and if conception should occur, pregnancy should be monitored more closely for potential complications. Patients should take vitamin B12, at least 400 μg/day of folic acid, and iron supplementation. Patients should be monitored for bowel obstruction, stricture, and nutritional deficiencies.
A systematic review of cohort studies evaluating the effect of bariatric surgery on pregnancy outcomes concluded that rates of adverse maternal and neonatal outcomes may be lower in obese women who have undergone bariatric surgery before conception [35]. A recent retrospective study showed a decreased risk in gestational diabetes in women who underwent bariatric surgery as compared with obese and morbidly obese controls who did not have bariatric surgery, but there was also a 17.4 % rate of small for gestational age (SGA) infants in the surgery group as compared to the control group (5.0 %) [36].
Providing Guidance for Weight Gain During Pregnancy
The ideal time for all of the above interventions is before pregnancy. However, if an overweight or obese patient presents in early pregnancy, most of the aforementioned recommendations are still appropriate [37, 38]. In addition, gestational weight gain (GWG) needs to be discussed at the first prenatal visit. In 2009, the IOM released its revised recommendations for gestational weight gain lowering the total weight gain recommended for women who are classified as obese at the time of conception (Table 3.1) [3, 39]. These weight gain recommendations are applicable to adult and adolescent mothers. Providers should discuss the GWG recommendations at length with patients, and GWG should be assessed at each visit. For women of short stature (<157 cm), the recommendation is to maintain the GWG at the lower end of what is recommended for prepregnancy BMI [40–43].
The American Congress of Obstetricians and Gynecologists has outlined recommended practices when managing pregnancy in a woman who is overweight or obese [3, 44]. First, similar to caring for women during preconception, it is critical to treat BMI as a vital sign in the newly gravid woman. The provider should clearly convey the diagnosis and show her the BMI value on a BMI chart. The provider should explain the risks associated with being obese in pregnancy and recommend a specific range of GWG based on IOM recommendations [5]. Finally the provider should discuss physical activity and diet during pregnancy. Although small studies examining effects of exercise on pregnancy outcomes have reported inconsistent findings, ACOG recommends 30 min or more of moderate exercise on most days of the week for pregnant women [45–49]. Using the same techniques described above, it is important to identify the patient’s readiness to change and use her current situation to help motivate her. The provider should give detailed information about resources available, including nutrition counseling, exercise-related materials, and how to access those resources. Some additional ideas to implement in practice that may help make weight loss more feasible for patients include providing patients with a pedometer, partnering with a local gym to provide discounts, or utilizing other community resources. Actual weight should be documented at each prenatal visit and appropriate feedback provided to the patient based on recommended GWG.
Lifestyle modification during pregnancy has not been studied quite as extensively as in the nongravid woman. Two recent systematic reviews assessing the evidence found no statistically significant difference in maternal or neonatal outcomes between women randomized to antenatal lifestyle intervention and those who received usual care [46, 47]. However, many of the included studies were limited by sample size, unclear randomization procedures, and attrition.
Research Gaps and the Next Generation of Research
Gaps in clinical practice for preconception care were outlined clearly in the CDC/ATSDR Preconception Care Work Group in 2006 [5]. The recommendations made at that time remain timely and relevant to current practice: (1) Individual responsibility across the lifespan: each woman, man, and couple should be encouraged to have a reproductive life plan; (2) Consumer awareness: increase public awareness of the importance of preconception health behaviors and preconception care services; (3) Preventive visits: risk assessment and educational and health promotion counseling should be part of every primary care visit for women of childbearing age to improve pregnancy outcomes; and (4) Interventions for identified risks: increase the proportion of women who receive interventions, in particular those with evidence of effectiveness.
The fourth recommendation captures the highest priority research gap for preconception care of the overweight and obese woman. There is limited evidence to guide providers and public health officials to the most effective interventions for weight loss in overweight and obese women who are considering pregnancy. Clinical trials of lifestyle interventions that target women considering pregnancy are critical to improving the long-term health of women regardless of their preferences or plans for childbearing [50, 51].
Conclusion
Our ability to confidently provide guidance on appropriate preconception interventions for overweight or obese women is limited by few clinical trials focusing on this particularly important time frame in the life of reproductive age women. Providers and public health officials should take advantage of the preconception period, which is an important teachable moment in the life of women.
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