Is exercise safe or useful for gestational diabetic women?

Clinical management of pregnancy in the obese mother: before conception, during pregnancy, and post partum

The global epidemic of obesity has led to an increasing number of obese women of reproductive age. Obesity is associated with reduced fertility, and pregnancies complicated by maternal obesity are associated with adverse outcomes, including increased risk of gestational diabetes, pre-eclampsia, preterm birth, instrumental and caesarean births, infections, and post-partum haemorrhage. The medical and obstetric management of obese women is focused on identifying, addressing, and preventing some of these associated complications, and is a daunting challenge given the high percentage of patients with obesity and few therapeutic options proven to improve outcomes in this population. The UK's National Institute for Health and Care Excellence guidelines and the American College of Obstetricians and Gynecologists recommend that all pregnant women follow a healthy diet, and consider at least half an hour of moderate physical activity per day during pregnancy. However, although obese women are often directed to seek the advice of a nutritionist and to limit gestational weight gain, guidelines for the management of pregnancy and delivery in this high-risk group are lacking. The post-partum period represents an important opportunity to optimise maternal health before the next pregnancy. As many of the physiological changes of pregnancy associated with maternal obesity are present from early pregnancy onward, reducing maternal obesity before conception is probably the best strategy to decrease the health burden associated with maternal obesity.

Exercise guidelines for gestational diabetes mellitus

The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. This disease has many detrimental consequences for the woman, the unborn foetus and child. The management of GDM aims to mediate the effects of hyperglycaemia by controlling blood glucose levels. Along with pharmacology and dietary interventions, exercise has a powerful potential to assist with blood glucose control. Due to the uncertainty of risks and benefits of exercise during pregnancy, women tend to avoid exercise. However, under adequate supervision exercise is both safe and beneficial in the treatment of GDM. Therefore it is vital that exercise is incorporated into the continuum of care for women with GDM. Medical doctors should be able to refer to competently informed exercise professionals to aid in GDM treatment. It is important that exercise treatment is informed by research. Hence, the development of evidence-based guidelines is important to inform practice. Currently there are no guidelines for exercise in GDM. This review aims to assess the efficacy of exercise for the management of GDM in order to establish an exercise prescription guideline specific to the condition. It is recommended that women with GDM should do both aerobic and resistance exercise at a moderate intensity, a minimum of three times a week for 30-60 min each time.

Lifestyle patterns in early pregnancy linked to gestational diabetes mellitus diagnoses when using IADPSG criteria. The St Carlos gestational study

Early-pregnancy lifestyle (EPL) could influence the development of gestational diabetes mellitus(GDM), depending on the diagnostic criteria used.

OBJECTIVE

We studied EPL in 1750 pregnant women using Carpenter-Coustan criteria(CCc), and in 1526 with the International Association of Diabetes and Pregnancy Study Groups criteria(IADPSGc).

METHODS

GDM risk factors were assessed in women between 24 and 28 weeks of gestational age during two consecutive years. A semiquantitative frequent-food-consumption questionnaire was used to evaluate lifestyle during pregnancy. Multiple logistic regression analysis was conducted to assess GDM risk with different lifestyle patterns.

RESULTS

Using IADPSGc, the GDM ORs (95%CI) for intake/week were: nuts >3 times: 0.59 (0.39-0.91; p < 0.015), refined cereals ≤1 serving: 0.72(0.58-0.89; p < 0.003), juices <4 servings: 0.77 (0.62-0.95; p < 0.017), cookies and pastries <4 servings: 0.71(0.57-0.89; p < 0.003) as compared to opposite habits. No significant nutritional patterns were found to be significant using CCc. The OR (95%CI) for GDM with none of the four risk patterns as compared to having three-four risk factors was 0.21(0.07-0.62; p < 0.005), remaining significant after stratification by BMI, age, obstetric events, parity and family history. The multiple logistic regression model including nutritional categories and pregestational BMI, age, obstetric history, parity, personal/family history, had an area under the curve(AUC) of the receiver operating curve(ROC) for the probability to predict GDM of 0.66 (CI 95%: 0.63-0.69; p < 0.001).

CONCLUSION

Our study is the first to identify four early-pregnancy nutritional patterns associated with the GDM when using IADPSGc. Adherence to a low-risk nutritional pattern from early pregnancy on could be an effective strategy for GDM prevention.

Supervised exercise-based intervention to prevent excessive gestational weight gain: a randomized controlled trial

OBJECTIVE

To study the effect on maternal weight gain of a supervised light- to moderate-intensity exercise-based intervention performed from the ninth week of pregnancy.

PARTICIPANTS AND METHODS

A total of 962 healthy pregnant women were randomly assigned to a standard care or exercise intervention group conducted between September 1, 2007, and January 31, 2011. The intervention included light- to moderate-intensity aerobic and resistance exercises performed 3 days a week (50-55 minutes per session). Excessive gestational weight gain was calculated on the basis of the 2009 Institute of Medicine (IOM) recommendations. Gestational body weight gain was calculated on the basis of the weight measured at the first prenatal visit (fifth to sixth weeks of gestation) and weight measured at the last visit to the clinic before delivery. Women were categorized into normal weight or overweight or obese.

RESULTS

Women in the intervention group gained less weight (adjusted mean difference, 1.039 kg; 95% CI, 0.534-1.545 kg; P<.001) and were less likely to gain weight above the IOM recommendations (odds ratio, 0.625; 95% CI, 0.461-0.847) compared with those in the standard care group. The main treatment effects according to body mass index category were that normal weight women in the intervention group gained less weight (adjusted mean difference, 1.393 kg; 95% CI, 0.813-1.972 kg; P<.001) and were less likely to gain weight above the IOM recommendations (odds ratio, 0.508; 95% CI, 0.334-0.774) than normal weight women who received standard care. No significant treatment effect was observed in overweight or obese women.

CONCLUSION

Supervised exercise of light to moderate intensity can be used to prevent excessive gestational weight gain, especially in normal weight women.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01790347.

Gestational diabetes mellitus: risks and management during and after pregnancy

Gestational diabetes mellitus (GDM) carries a small but potentially important risk of adverse perinatal outcomes and a long-term risk of obesity and glucose intolerance in offspring. Mothers with GDM have an excess of hypertensive disorders during pregnancy and a high risk of developing diabetes mellitus thereafter. Diagnosing and treating GDM can reduce perinatal complications, but only a small fraction of pregnancies benefit. Nutritional management is the cornerstone of treatment; insulin, glyburide and metformin can be used to intensify treatment. Fetal measurements complement maternal glucose monitoring in the identification of pregnancies that require such intensification. Glucose testing shortly after delivery can stratify the short-term diabetes risk in mothers. Thereafter, annual glucose and HbA(1c) testing can detect deteriorating glycaemic control, a harbinger of future diabetes mellitus, usually type 2 diabetes mellitus. Interventions that mitigate obesity or its metabolic effects are most potent in preventing or delaying diabetes mellitus. Lifestyle modification is the primary approach; use of medications for diabetes prevention after GDM remains controversial. Family planning enables optimization of health in subsequent pregnancies. Breastfeeding may reduce obesity in children and is recommended. Families should be encouraged to help children adopt lifestyles that reduce the risk of obesity.

Diagnosis and treatment of hyperglycemia in pregnancy

Hyperglycemia in pregnancy is an opportunity for women at risk for complications during pregnancy and beyond to change their life course to improve outcomes for themselves and their offspring. Providers of diabetes care during pregnancy complicated by hyperglycemia in pregnancy have the unique opportunity to make a significant difference.

The Effect of Exercise During Pregnancy on Maternal Outcomes: Practical Implications for Practice

The American College of Obstetricians and Gynecologists recommends that women with low-risk pregnancies participate in moderate-intensity exercise during their pregnancy. Currently, only 15.1% of pregnant women exercise at the recommended levels, which is significantly lower than the general population's 45%. One potential reason is that exercise during pregnancy is perceived as risky. In this article, the authors provide a critical review of the literature examining the effect of exercise on preeclampsia, gestational diabetes, weight gain, labor and birth, and other issues associated with pregnancy. Overall, the evidence indicates that exercise during pregnancy is safe and perhaps even reduces the risk of preeclampsia and gestational diabetes. The evidence for weight gain and labor and birth (rates of cesarean sections, duration of labor) is mixed. Unfortunately, much of the research examining exercise during pregnancy is observational, and the few randomized controlled trials that do exist are small and inadequately powered. Taken together, given the potential benefits of exercise during pregnancy and the lack of evidence for harmful effects on the mother and newborn, practitioners should encourage their healthy pregnant patients to exercise. Practical guidelines for recommending exercise to pregnant women are presented.

Optimizing the outcome of pregnancy in obese women: from pregestational to long-term management

The obesity epidemic is of some concern in women of reproductive age. Maternal obesity is associated with many pregnancy complications, especially gestational diabetes and hypertensive disorders of pregnancy. Delivery in obese women is characterized by a high caesarean-section rate and an increased risk of anaesthetic and postoperative complications. Weight retention after birth may increase the risk of type 2 diabetes in the long term. Foetal risks include macrosomia, malformations and increased perinatal mortality, with the long-term infant health marked by a higher risk of obesity and metabolic disorders. Optimal management includes preconception counselling, pregravid weight-loss programmes, monitoring of gestational weight gain, repeated screening for pregnancy complications and long-term follow-up to minimize the social and economic consequences of pregnancy in overweight women.

[Fifteen practical questions concerning gestational diabetes]

With a review of the current literature, a clarification on screening and management of gestational diabetes is hereby set out, within the frame of a Clinical Expert Series. According to the ethnic group, the prevalence varies from 1 to 14%. The treatment is based on dietary advice, insulin. The ACHOIS study demonstrates that the treatment of gestational diabetes significantly decreases perinatal complications (4 to 1%). The place of the oral treatment (glyburide) remains to be defined. In most countries, diagnosis rests on oral glucose test tolerance: Sullivan 50 g glucose test (1 hour) and 100 g test of glucose if positive (3 hours); WHO 75 g test (2 hours). The screening can be systematic or only on risk factors (wide variations between studies). Screening of gestational diabetes is required because its management improves pregnancy outcomes. Despite this, there is no consensus on the strategy of screening and diagnosis.

Exercise for diabetic pregnant women

BACKGROUND

Diabetes in pregnancy may result in unfavourable maternal and neonatal outcomes. Exercise was proposed as an additional strategy to improve glycaemic control. The effect of exercise during pregnancies complicated by diabetes needs to be assessed.

OBJECTIVES

To evaluate the effect of exercise programs, alone or in conjunction with other therapies, compared to no specific program or to other therapies, in pregnant women with diabetes on perinatal and maternal morbidity and on the frequency of prescription of insulin to control glycaemia. To compare the effectiveness of different types of exercise programs on perinatal and maternal morbidity.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 December 2005).

SELECTION CRITERIA

All known randomised controlled trials evaluating the effect of exercise in diabetic pregnant women on perinatal outcome and maternal morbidity.

DATA COLLECTION AND ANALYSIS

We evaluated relevant studies for meeting the inclusion criteria and methodological quality. Three review authors abstracted the data. For all data analyses, we entered data based on the principle of intention to treat. We calculated relative risks and 95% confidence intervals for dichotomous data.

MAIN RESULTS

Four trials, involving 114 pregnant women with gestational diabetes, were included in the review. None included pregnant women with type 1 or type 2 diabetes. Women were recruited during the third trimester and the intervention was performed for about six weeks. The programs generally consisted in exercising three times a week for 20 to 45 minutes. We found no significant difference between exercise and the other regimen in all the outcomes evaluated.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend, or advise against, diabetic pregnant women to enrol in exercise programs. Further trials, with larger sample size, involving women with gestational diabetes, and possibly type 1 and 2 diabetes, are needed to evaluate this intervention.

Exercise or other physical activity for preventing pre-eclampsia and its complications

BACKGROUND

The association between an increase in regular physical activity and a reduction in the risk of hypertension is well documented for non-pregnant people. It has been suggested that exercise may help prevent pre-eclampsia and its complications. Possible adverse effects of increased physical activity during pregnancy, particularly on the risk of preterm birth and fetal growth restriction, are unclear. It is, therefore, important to assess whether exercise reduces the risk of pre-eclampsia and its complications and, if so, whether these benefits outweigh the risks.

OBJECTIVES

To assess the effects of exercise, or increased physical activity, on prevention of pre-eclampsia and its complications.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (December 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2005, Issue 1), and EMBASE (2002 to February 2005).

SELECTION CRITERIA

Studies were included if these were randomised trials evaluating the effects of exercise or increased physical activity during pregnancy for women at risk of pre-eclampsia.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and extracted data. Data were entered on Review Manager software for analysis, and double checked for accuracy.

MAIN RESULTS

Two small, good quality trials (45 women) were included. Both compared moderate intensity regular aerobic exercise with maintenance of normal physical activity during pregnancy. The confidence intervals were wide and crossed the line of no effect for all reported outcomes including pre-eclampsia (relative risk 0.31, 95% confidence interval 0.01 to 7.09).

AUTHORS' CONCLUSIONS

There is insufficient evidence for reliable conclusions about the effects of exercise on prevention of pre-eclampsia and its complications.

Perceived Exertion in Physical Activity and Risk of Gestational Diabetes Mellitus

BACKGROUND

Physical activity has been associated with decreased risk of gestational diabetes mellitus. Expanding on 2 previously published analyses of absolute exertion measures (time spent and energy expended), we assessed the relation between perceived exertion during usual prepregnancy recreational physical activity and gestational diabetes.

METHODS

We analyzed data from a Washington State 1998-2002 case-control study (216 cases, 472 controls) and a 1996-2002 prospective cohort study (897 participants) separately. We used logistic regression models to derive odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among case-control participants, risk of gestational diabetes was markedly lower for women who reported very strenuous to maximal exertion in usual activity during the year before pregnancy versus those who reported negligible or minimal exertion (adjusted OR = 0.19; CI = 0.15-0.50). There was a direct inverse relation between perceived exertion and risk of gestational diabetes. This relation was also evident among the subset of participants who did not meet physical activity guidelines in the year before pregnancy. Similarly, the OR among cohort participants reporting very strenuous to maximal exertion was 0.57 (0.24-1.37) versus those reporting negligible to moderate exertion.

CONCLUSIONS

These results suggest that risk of gestational diabetes is inversely related to the exertion perceived during recreational physical activity in the year before pregnancy. Perceived exertion may be a valuable addition to behavior and fitness measures in assessing relations between physical activity and pregnancy-related health outcomes.

A case-control study of maternal recreational physical activity and risk of gestational diabetes mellitus

Despite the maternal and infant morbidity associated with gestational diabetes mellitus (GDM), few modifiable risk factors have been identified. We explored the relation between recreational physical activity performed during the year before and during the first 20 weeks of pregnancy and the risk of GDM. 155 GDM cases and 386 normotensive, non-diabetic pregnant controls provided information about the type, intensity, frequency, and duration of physical activity performed during these time periods. Women who participated in any recreational physical activity during the first 20 weeks of pregnancy, as compared with inactive women, experienced a 48% reduction in risk of GDM (odds ratio [OR] = 0.52; 95% confidence interval [CI] 0.33-0.80). The number of hours spent performing recreational activities and the energy expended were related to a decrease in GDM risk. No clear patterns related to distance walked and pace of walking emerged. Daily stair climbing, when compared with no stair climbing, was associated with a 49-78% reduction in GDM risk (P for trend <0.011). Recreational physical activity performed during the year before the index pregnancy was also associated with statistically significant reductions in GDM risk, but women who engaged in physical activity during both time periods experienced the greatest reduction in risk (OR = 0.40; 95% CI 0.23-0.68). These data suggest that recreational physical activity performed before and/or during pregnancy is associated with a reduced risk of GDM.

Aerobic exercise during pregnancy reverts maternal insulin resistance in rats

PURPOSE AND METHODS

To determine whether pregnancy modifies the effect of aerobic exercise on insulin responsiveness, female rats were mated or kept nonpregnant and exercised or not on a treadmill (10 degrees slope, 20 m.min-1) 5 d.wk-1 during a 20-min period that was increased progressively up to 70 min on the 19th d. On day 20, a hyperinsulinemic euglycemic clamp was performed with 0.8 IU insulin.h-1.kg-1 under conscious conditions.

RESULTS

Food intake and body weight, circulating lactic acid, glucose, and insulin as well as fetal body weight and number were unaffected by the exercise protocol. The rate of glucose infusion required to maintain basal glucose levels during the clamp was similar in exercised and nonexercised virgin rats and significantly lower in pregnant than in virgin nonexercised rats. However, in exercised pregnant rats the glucose infusion rate was almost as high as in the exercised virgin rats.

CONCLUSIONS

The results show that although our aerobic exercise protocol does not affect insulin responsiveness in nonpregnant rats, it completely reverts the insulin resistance present in late pregnant rats.

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.