Nutritional management of the obese gestational diabetic pregnant woman

Gestational diabetes mellitus: challenges in diagnosis and management

Gestational diabetes mellitus (GDM) is a well-characterized disease affecting a significant population of pregnant women worldwide. It has been widely linked to undue weight gain associated with factors such as diet, obesity, family history, and ethnicity. Poorly controlled GDM results in maternal and fetal morbidity and mortality. Improved outcomes therefore rely on early diagnosis and tight glycaemic control. While straightforward protocols exist for screening and management of diabetes mellitus in the general population, management of GDM remains controversial with conflicting guidelines and treatment protocols. This review highlights the diagnostic and management options for GDM in light of recent advances in care.

Gestational diabetes mellitus

Gestational diabetes mellitus is one of the most common medical problems that results from an increase in the insulin resistance as well as an impairment of the compensatory increase in insulin secretion from the beta cells of the pancreas. It serves as a metabolic stress test that uncovers underlying insulin resistance and beta-cell dysfunction. Gestational diabetes is associated with a variety of maternal and fetal complications, most notably macrosomia. Controversy surrounds the ideal approach for detecting gestational diabetes, andthe approaches recommended for screening and diagnosis are largely based on expert opinion. Controlling maternal glycemia with Medical Nutrition Therapy, close monitoring of blood glucose levels and treatment with insulin if blood glucose levels are not at goal has been shown to decrease fetal and maternal morbidities. Other treatment modalities, such as oral agents, need further study to validate their safety and efficacy. Finally, postpartum management of women with Gestational diabetes is critical because of their markedly increased risk of Type 2 diabetes in the future. Efforts should be made to prevent gestational diabetes in subsequent pregnancies. Because body fat and diet contribute to the risk of gestational diabetes mellitus, patients who lose weight before pregnancy and follow an appropriate diet may lower their risk of gestational diabetes mellitus.

Turning the tide: type 2 diabetes trends in offspring of mothers with gestational diabetes mellitus

In this review, the thesis is presented that maternal hyperglycemia produces an overnourished, fat fetus. If the fetus has a predisposition for type 2 diabetes, then the fat deposition in the fetus is predominantly in the fetal visceral cavity. Visceral fat deposition is the origin of insulin resistance. The fat fetus begins life with its pancreatic output of insulin compromised. Thus, the stage is set for developing type 2 diabetes in its lifetime. This review supports the hypothesis that normalization of maternal nutrition and fucose will decrease the risk of type 2 diabetes.

Pregnancy and Diabetes Management: Advances and Controversies

BACKGROUND

The treatment of diabetes in pregnancy has potentially far-reaching benefits for both pregnant women with diabetes and their children and may provide a cost-effective approach to the prevention of obesity, type 2 diabetes mellitus, and metabolic syndrome. Early and accurate diagnosis of diabetes in pregnancy is necessary for optimizing maternal and fetal outcomes.

CONTENT

Optimal control of diabetes in pregnancy requires achieving normoglycemia at all stages of a woman's pregnancy, including preconception and the postpartum period. In this review we focus on new universal guidelines for the screening and diagnosis of diabetes in pregnancy, including the 75-g oral glucose tolerance test, as well as the controversy surrounding the guidelines. We review the best diagnostic and treatment strategies for the pregestational and intrapartum periods, labor and delivery, and the postpartum period, and discuss management algorithms as well as the safety and efficacy of diabetic medications for use in pregnancy.

SUMMARY

Global guidelines for screening, diagnosis, and classification have been established, and offer the potential to stop the cycle of diabetes and obesity caused by hyperglycemia in pregnancy. Normoglycemia is the goal in all aspects of pregnancy and offers the benefits of decreased short-term and long-term complications of diabetes.

Obesity and gestational diabetes

The prevalence of both obesity and gestational diabetes mellitus (GDM) is increasing worldwide. GDM affects about 7% of all pregnancies and is defined as any degree of impaired glucose tolerance during gestation. The presence of obesity has a significant impact on both maternal and fetal complications associated with GDM. These complications can be addressed, at least in part, by good glycaemic control during pregnancy. The significance and impact of obesity in women with GDM are discussed in this article, together with treatment options, the need for long-term risk modification and postpartum follow-up.

Intensive insulin therapy in pregnancy: strategies for successful implementation in pregestational diabetes mellitus

The role of intensive insulin therapy (IIT) in the reduction of long-term diabetes-related complications is well established. Normal blood glucose level prior to and during pregnancy is critical in reducing both short- and long-term morbidity and mortality in mother and infant. IIT in pregnancy, though occasionally challenging, is necessary to achieve and maintain normal blood glucose level during pregnancy. Current knowledge and recent advances in insulin formulations and delivery systems have improved our ability to achieve glycemic targets in pregnancy while limiting maternal and fetal morbidity. The objective of this review is to discuss contemporary strategies for successful use of IIT in pregnancy.

Targeting postprandial hyperglycemia

In healthy individuals, blood glucose levels in the fasting state are maintained by the continuous basal-level insulin secretion. After a meal, the rise in postprandial glucose (PPG) is controlled by the rapid pancreatic release of insulin, stimulated by both glucose and the intestinal production of the incretins glucose-dependent insulinotropic polypeptide and glucagon-like peptide 1. In diabetic individuals, postprandial insulin secretion is insufficient to suppress an excessive rise in PPG. There is increasing evidence that elevated PPG exerts a more deleterious effect on the vascular system than elevation of fasting plasma glucose. In particular, individuals with normal fasting plasma glucose but impaired glucose tolerance have significantly increased risk of cardiovascular events. With the recognition of the importance of PPG and the availability of new pharmacologic options, management of diabetes will shift to greater attention to PPG levels. The prototype for such an approach is in the treatment of gestational diabetes and diabetic pregnancies where PPG is the primary target of efforts at glycemic control. These efforts have been extremely successful in improving the outlook for diabetic pregnant women. There are many approaches to reduction of PPG; dietary management and promotion of exercise are very effective. Sulfonylureas, meglitinides, metformin, thiazolidinediones, and disaccharidase inhibitors all counteract PPG elevation. The development of glucagon-like peptide 1 agonists such as exendin and dipeptidyl peptidase IV inhibitors such as vildagliptin offers a new approach to suppression of PPG elevation. New semisynthetic insulin analogues permit a more aggressive response to postprandial glucose elevation, with lower risk of hypoglycemia, than with regular insulin. Inhaled insulin also has a rapid onset of action and offers benefits in PPG control. It is proposed that an aggressive treatment approach focusing on PPG, similar to the current standards for diabetic pregancies, be directed at individuals with diabetes and impaired glucose tolerance.

Nutrition and pregnancy: the link between dietary intake and diabetes

Pregnancy is a time when serial metabolic changes in the mother are carefully regulated to provide optimum substrate to both mother and fetus. Subtle perturbations in maternal metabolism can have implications not only for the index pregnancy, but also for future generations. The literature provides evidence that maternal nutrition plays a major role in the destiny of the offspring. Both maternal malnutrition and overnutrition are associated with subsequent diabetes in the offspring. Pregnancy represents a window of opportunity for health care providers to change dietary patterns toward habits that will be healthier for the individual now, as well as impacting on the future. The challenge for clinicians is to provide nutritional information based on scientific evidence that facilitates the normalization of fetal nutrition, and thus minimize the risk that the child will develop diabetes.

Achieving Euglycaemia in Women with Gestational Diabetes Mellitus

Gestational diabetes mellitus is one of the major medical complications of pregnancy. Untreated, the mother and the unborn child may experience morbidity and fetal death may even occur. It is important to diagnose and treat all hyperglycaemia appearing during pregnancy. Ideally, a screening and diagnostic test that identified all women at risk for hyperglycaemia-associated complications would be employed in all pregnant women. Unfortunately, there is no such test available currently. The best alternative is to administer an oral glucose challenge test to all pregnant women and then apply the best strategies for interpretation. This article discusses the limitations of our present diagnostic tools and suggests an option for the clinician until the definitive test has been elucidated. In addition, this article outlines one dietary and management strategy that has been associated with an outcome of pregnancy that is similar to the outcome of pregnancies in healthy women. This strategy includes starting with a "euglycaemic" diet (comprising < 40% carbohydrates and > or =40% fat), which can then be individualised according to the patient's glucose levels. Appropriate exercise, such as arm ergometer training, may enhance the benefits of diet control. For patients who require insulin, if the fasting glucose level is >90 mg/dL or 5 mmol/L (whole blood capillary) then NPH insulin (insulin suspension isophane) should be given before bed, beginning with dosages of 0.2 U/kg/day. If the postprandial glucose level is elevated, pre-meal rapid-acting insulin should be prescribed, beginning with a dose of 1U per 10g of carbohydrates in the meal. If both the fasting and postprandial glucose levels are elevated, or if a woman's postprandial glucose levels can only be blunted if starvation ketosis occurs, a four-injections-per-day regimen should be prescribed. The latter can be based on combinations of NPH insulin and regular human insulin, timed to provide basal and meal-related insulin boluses. The total daily insulin dose for the four-injection regimen should be adjusted according to pregnant bodyweight and gestational week (0.7-1 U/kg/day); doses may need to be increased for the morbidly obese or when there is twin gestation. There is now some evidence that insulin lispro, other insulin analogues and oral antihyperglycaemic drugs may be beneficial in gestational diabetes, and more data on these agents are awaited with interest.

A randomised controlled trial of dietary energy restriction in the management of obese women with gestational diabetes

A randomised controlled trial was designed to determine the effect of moderate 30% maternal dietary energy restriction on the requirement for maternal insulin therapy and the incidence of macrosomia in gestational diabetes. Although the control group restricted their intake to a level similar to that of the intervention group (6,845 kiloJoules (kJ) versus 6,579 kJ), the resulting cohort could not identify any adverse effect of energy restriction in pregnancy. Energy restriction did not alter the frequency of insulin therapy (17.5% in the intervention group and 16.9% in the control group). Mean birthweight (3,461 g in the intervention group and 3,267 g in the control group) was not affected. There was a trend in the intervention group towards later gestational age at commencement of insulin therapy (33 weeks versus 31 weeks) and lower maximum daily insulin dose (23 units versus 60 units) which did not reach statistical significance. Energy restriction did not cause an increase in ketonemia.

Medical nutritional therapy in pregnant women with pregestational diabetes mellitus

OBJECTIVE

Diabetic women now can have the same chances as nondiabetic women to have a healthy infant. The reduction of risk associated with pregnancies complicated by diabetes can only be assured if normoglycemia is achieved before and during pregnancy. This review is intended to provide guidelines and scientific evidence for the optimal diet for the Type 1 or Type 2 diabetic woman.

METHODS

The literature over the past 10 years is presented. Those diets which achieved the best outcome of pregnancies complicated by diabetes (as evidenced by term delivery of a healthy, normal weight infant) are then outlined.

RESULTS

Diets which provide adequate calories without causing postprandial hyperglycemia or premeal ketosis are found to be based on body weight and gestational week of the pregnancy. Quantity of carbohydrate in the meal plan emerges as the most important component in achieving and maintaining glucose control.

CONCLUSIONS

The medical nutritional therapy for the Type 1 and Type 2 diabetic woman is a necessary component of the overall strategy to achieve and maintain normoglycemia and thus achieve the best outcome of pregnancy.

Sweet taste and intake of sweet foods in normal pregnancy and pregnancy complicated by gestational diabetes mellitus

BACKGROUND

Dietary compliance in gestational diabetes mellitus (GDM) is poor. Changes in sweet taste perception might alter food preferences in GDM, making dietary compliance difficult to achieve. These indexes have never been studied in GDM.

OBJECTIVES

This study documented changes in sweet taste perception and dietary intakes in pregnant women with and without GDM and determined whether these differences persisted postpartum.

DESIGN

Subjects were 30 pregnant women without GDM, 25 pregnant women with recently diagnosed GDM, and 12 nonpregnant control subjects. Pregnant women were tested at 28-32 wk gestation and retested 12 wk postpartum. Subjects evaluated the taste of strawberry-flavored milks with different sucrose (0-10%) and fat (0-10%) contents and glucose solutions (10-160 mmol/L).

RESULTS

Women with GDM showed no differences in liking for the milk samples across test sessions and their liking ratings were not significantly different from those of nonpregnant control subjects. Women without GDM liked the 10% sucrose-sweetened milk samples less during pregnancy than at 12 wk postpartum (P </= 0.01), at which time their ratings were not significantly different from those of nonpregnant control subjects. In women with GDM, plasma glucose after a 50-g glucose load was correlated with both increased liking for the taste of glucose (r = 0.64, P </= 0.001) and higher consumption of fruit and fruit juices (r = 0.45, P </= 0.02).

CONCLUSIONS

Normal pregnancy was associated with a lower preference for 10% sucrose-sweetened milk samples late in gestation than postpartum, whereas GDM was associated with no such differences. Plasma glucose in women with GDM was related to a higher preference for the sweet taste of glucose and higher dietary sweet-food intakes from fruit and fruit juices. These findings have important implications for the dietary management of GDM.

Gestational diabetes

OBJECTIVE

To review the detection, diagnosis, and clinical management of gestational diabetes.

DATA SOURCES

MEDLINE, Gestational Diabetes Guideline Review, 1968-1998.

STUDY SELECTION

By the author.

DATA EXTRACTION

By the author.

DATA SYNTHESIS

Gestational diabetes is a common complication of pregnancy, occurring in 2% to 6% of pregnancies. Uncontrolled gestational diabetes is associated with increased infant morbidity and mortality, macrosomia, and cesarean deliveries, and is a strong marker for the future development of maternal diabetes mellitus. Women with risk factors for gestational diabetes should be screened for glucose intolerance at 24 to 28 weeks' gestation. If a screening plasma glucose concentration is 140 mg/dL or greater one hour after a 50 gram oral glucose load, then a diagnostic 100 gram, three-hour oral glucose tolerance test should be performed. Medical nutrition therapy is the cornerstone of management and must be designed to meet individual needs. Self-monitoring of blood glucose should be taught to and performed by all women with gestational diabetes. Insulin, which does not readily cross the placental barrier, is the drug therapy of choice in women failing medical nutrition therapy.

CONCLUSION

Pharmacists can optimize overall care by educating, monitoring, and intervening or assisting the patient in the management of gestational diabetes.

Nutrition management in women with gestational diabetes mellitus: a review by ADA's Diabetes Care and Education Dietetic Practice Group

Gestational diabetes mellitus (GDM) is the most common medical disorder complicating pregnancy that requires the services of a registered dietitian. Despite three international workshops on GDM, many questions remain regarding its epidemiology, pathophysiology, screening, diagnosis, and management. Registered dietitians encounter these controversial issues when working with women referred for GDM education and counseling. Nutrition intervention remains the cornerstone of therapy. The purpose of this article is not to provide practice guidelines but to review the literature and current practices in research centers across the United States. Registered dietitians are in a position to individualize nutrition care to each woman's needs and to participate in the decision-making process of nutrition management.