Management of gestational diabetes

Glycemic targets for the optimal treatment of GDM

Lowering glucose is of pivotal importance in the treatment of diabetes in pregnancy. A spectrum of different glucose thresholds can be established and used appropriately to prevent each complication. This article outlines the concept of normality and what definition of normality should be used to evaluate the relationship between the level of glycemia and perinatal outcome.

Oral Hypoglycemic Agents in pregnancy: An Update

INTRODUCTION

Traditionally, insulin has been the gold standard in the management of Type 2 diabetes in pregnancy and gestational diabetes. However, insulin therapy can be inconvenient because of the needs for multiple injections, its associated cost, pain at the injection site, need for refrigeration, and skillful handling of the syringes. This has led to the exploration of oral hypoglycemic agents as an alternative to insulin therapy.

OBJECTIVES

This review examines and evaluates the evidences on the efficacy, safety, and current recommendations of oral hypoglycemic agents.

CONCLUSION

The evidence of this study supports the use of glyburide and metformin in the management of Type 2 diabetes and gestational diabetes with no increased risk of neonatal hypoglycemia or congenital anomalies. The safety of these oral hypoglycemic agents are limited to the prenatal period and more randomized controlled trials are required to provide information on the long-term follow up on neonatal and cognitive development.

Effect of ambulatory versus hospital treatment for gestational diabetes or hyperglycemia on infant mortality rates: a systematic review

CONTEXT AND OBJECTIVE

Pregnancies complicated by diabetes are associated with increased neonatal and maternal complications. The most serious maternal complication is the risk of developing type 2 diabetes, 10-12 years after the delivery. For rigorous control over blood glucose, pregnant women are treated through ambulatory management or hospitalization. The aim of this study was to evaluate the effectiveness of ambulatory management versus hospitalization in pregnancies complicated by diabetes or hyperglycemia.

DESIGN AND SETTING

Systematic review conducted in a public university hospital.

METHODS

A systematic review of the literature was performed and the main electronic databases were searched. The date of the most recent search was September 4, 2011. Two authors independently selected relevant clinical trials, assessed their methodological quality and extracted data.

RESULTS

Only three studies were selected, with small sample sizes. There was no statistically significance different between ambulatory management and hospitalization, regarding mortality in any of the subcategories analyzed: perinatal and neonatal deaths (relative risk [RR] 0.65; 95% confidential interval [CI]: 0.11 to 3.84; P = 0.63); neonatal deaths (RR 0.29; 95% CI: 0.01 to 6.07; P = 0.43); and infant deaths (RR 0.29; 95% CI: 0.01 to 6.07; P = 0.43).

CONCLUSIONS

This review, based on studies with high or moderate risk of bias, showed that there was no statistically significant difference between ambulatory management and hospital care, regarding reduction of mortality rates in pregnancies complicated by diabetes or hyperglycemia. It also suggested that there is a need for further randomized controlled trials on this issue.

Type 2 diabetes in pregnancy - An increasing problem

The worldwide epidemic in type 2 diabetes has been associated with an increased diagnosis in young adults. This has lead to a rapid rise in the number of pregnancies complicated by type 2 diabetes. Studies have shown risk of serious adverse outcome, including congenital malformation and perinatal mortality, is the same, or increased, in type 2 diabetes compared to type 1 diabetes. Despite improved glycaemic control in type 2 diabetes compared to type 1 diabetes, rates of perinatal morbidity, including preterm birth and macrosomia, appear to be similar. Risk factors associated with poor pregnancy outcome in women with type 2 diabetes include obesity, ethnicity and poor pregnancy preparation. This review will cover practical aspects of management of type 2 diabetes before, during and after pregnancy, including prepregnancy care, safety of oral hypoglycaemic agents, glycaemic management during labour, and choice of effective contraception.

Prevention of gestational diabetes mellitus: a review of studies on weight management

Entering pregnancy with overweight, obesity or gaining excessive gestational weight could increase the risk of gestational diabetes mellitus (GDM), which is associated with negative consequences for both the mother and the offspring. The objective of this article was to review scientific evidence regarding the association between obesity and GDM, and how weight management through nutritional prevention strategies could prove successful in reducing the risk for GDM. Studies published between January 1975 and January 2009 on the relationship between GDM, pre-pregnancy body mass index (BMI), gestational weight gain and nutritional prevention strategies were included in this review. Results from these reports suggest that maternal obesity assessed by pre-pregnancy BMI is associated with an increased risk of GDM. They also show an association between gestational weight gain and increased risk for GDM. Higher dietary fat and lower carbohydrate intakes during pregnancy appear to be associated with a higher risk for GDM, independent of pre-pregnancy BMI. Some studies showed that restricting energy and carbohydrates could minimize gestational weight gain. However, a firm conclusion on the most effective nutritional intervention for the control of gestational weight gain and glycaemic responses could not be reached based on available studies. In light of the studies reviewed, we conclude that weight management through nutritional prevention strategies could be successful in reducing the risk of GDM. Further studies are required to identify the most effective diet composition to prevent GDM and excessive gestational weight gain.

A walking intervention improves capillary glucose control in women with gestational diabetes mellitus: a pilot study

Exercise prescriptions that can be translated into clinical recommendations are clearly needed for women with gestational diabetes mellitus (GDM). A pilot project was developed to document the effectiveness of a structured low-intensity walking protocol on capillary glucose control in GDM women. Ten GDM women followed conventional management of diet and insulin therapy, plus a low-intensity walking program (W) from diagnosis to delivery. Capillary glucose concentrations, insulin requirements, and pregnancy outcomes were compared with a matched cohort by body mass index (BMI), age, and insulin usage (20 GDM women who followed conventional management alone (C)). Baseline capillary glucose concentrations were not significantly different between the W and C groups. The W group had an average acute drop in capillary glucose concentration from pre- to post-exercise of 2.0 mmol x L(-1). In addition, the W group had significantly lower mean glucose concentrations in the fasted state and 1 h after meals than the C group in the week prior to delivery. These lower glucose concentrations were achieved while requiring fewer units of insulin per day (C, 0.50 +/- 0.37 U x kg(-1); W, 0.16 +/- 0.13 U x kg(-1); p < 0.05), injected less frequently. These results suggest an effective role in glucose regulation for this structured walking program.

Is insulin lispro safe in pregnant women: Does it cause any adverse outcomes on infants or mothers?

AIM

To determine the rate of major congenital anomalies and complications retrospectively in offspring of women with diabetes mellitus treated insulin lispro.

MATERIAL AND METHODS

Twenty-seven patients had used insulin lispro (ILYS) and 59 patients had used regular human insulin (RHI) during the pregnancy period were evaluated. We also evaluated and analyzed the results of 53 of the 86 women who had gestational diabetes mellitus only. They were not using insulin aspart or insulin glarjine. We evaluated the birth weight, congenital anamolies, mode of delivery, abortus and stillbirth rates.

RESULTS

Mean HbA1c level was 6.27+2.23 for ILYS group and 7.07+2.09 for RHI group (p: 0.067). The duration of diabetes, gestational age, mode of delivery, type of diabetes, number of liveborn, stillbirth and miscarriages were not stastically different between all groups (p>0.05). Nine (15.25%) of 59 infants treated with RHI had congenital anomalies and one stillborn. The infants in ILYS-receiving group had no congenital anomalies but one pregnant (3.70%) had a stillborn. The difference in incidence of congenital anomalies between those using ILYS and RHI was not statistically significant (p: 0.157). There was also no difference in respect to congenital anomalies of gestational diabetic groups which used either ILYS or RHI.

CONCLUSION

Major congenital anomalies for offspring of mothers treated with ILYS are similar with RHI group. Although HbA1c levels were lower in ILYS group, all outcomes are similar with RHI. So ILYS is an alternative choice in treatment of pregnant women with DM.

Pregnancy outcome in gestational diabetes

OBJECTIVE

To assess maternal and neonatal outcomes of gestational diabetes mellitus (GDM) following glycemic screening and diabetic management, with special focus on concurrent GDM and pre-eclampsia.

METHODS

A retrospective chart review of 782 women diagnosed with and treated for GDM at a Chinese university teaching hospital. Data on maternal and neonatal outcome, glycemic control, concurrent pre-eclampsia, and diabetic management were collected and analyzed.

RESULTS

The incidence of GDM was 3.8%. Of the affected women, 62.9% were managed with diet only and the remainder received insulin treatment. Overall, 80.7% had good glycemic control. Poor glycemic control and concurrent pre-eclampsia correlated with maternal and neonatal complications.

CONCLUSION

Aggressive management for tight glycemic control improves maternal and neonatal outcomes in women with GDM.

Overweight and obese in gestational diabetes: the impact on pregnancy outcome

OBJECTIVE

We sought to investigate the relationship between prepregnancy weight, treatment modality (diet or insulin), level of glycemic control, and pregnancy outcome.

STUDY DESIGN

We recruited women with gestational diabetes (GDM) from inner city prenatal clinics. All women were instructed in the use of an intensified management protocol using memory reflectance meters. Outcomes were analyzed according to maternal prepregnancy body mass index (BMI, kg/m 2 ) categories: normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9), and obese (BMI > or =30), and by diet or insulin therapy and glycemic control (mean blood glucose <100 mg/dL = good control). Pregnancy outcome variables included a composite outcome (at least 1 of the following: neonatal metabolic complications, large-for-gestational age or macrosomic infants, NICU admission for >24 hours, and the need for respiratory support) (not including oxygen therapy). In addition to composite outcome, a bivariate analysis was performed for each single variable, including preeclampsia and cesarean section delivery.

RESULTS

Four thousand and one women were enrolled. Obese women who achieved targeted levels of glycemic control had comparable pregnancy outcomes to normal weight and overweight women only when they were treated with insulin. Normal weight women treated with diet therapy who achieved targeted levels of glycemic control had good outcomes, but obese women treated with diet therapy who achieved targeted levels of glycemic control, nevertheless, had a 2- to 3-fold higher risk for adverse pregnancy outcome when compared with overweight and normal weight patients with well-controlled GDM. Women with GDM who failed to achieve established levels of glycemic control had significantly higher adverse pregnancy outcomes in all 3 maternal weight groups.

CONCLUSION

In obese women with BMI > or =30 with GDM, achievement of targeted levels of glycemic control was associated with enhanced outcome only in women treated with insulin.

Is There a Role for Oral Antihyperglycemics in Gestational Diabetes and Type 2 Diabetes during Pregnancy?

Diabetes mellitus is a heterogeneous disorder of glucose intolerance that is generally classified into the following categories: type 1 and type 2 diabetes and gestational diabetes (GDM). Currently, the number of pregnancies complicated by type 2 diabetes and GDM exceed those affected by type 1 diabetes. Numerous studies have established a direct relationship between maternal glycemic control and neonatal outcomes for all types of diabetes. Therefore, modern treatment protocols during pregnancy emphasize strict glycemic control by a combination of diet and medication. Traditionally, insulin therapy has been considered the gold standard for management because of its efficacy in achieving tight glucose control and the fact that it does not cross the placenta. Since GDM and type 2 diabetes are characterized by insulin resistance and relatively decreased insulin secretion, treatment with oral antihyperglycemic agents that target these defects is of potential interest. However, because of concerns regarding transplacental passage and, therefore, the possibility of fetal teratogenesis and prolonged neonatal hypoglycemia, these agents are not currently recommended in pregnancy. There are no randomized controlled trials on which to draw conclusions regarding the teratogenicity of these oral agents. However, most retrospective studies and the published clinical experience have not demonstrated an increased risk of malformed infants among women treated with oral antihyperglycemic agents. Rather, the data indicate that the increased risk for major congenital anomalies appears to be related to maternal glycemic control prior to and during conception. These studies and currently available data on the use of both metformin and sulfonylureas in pregnancy have also failed to demonstrate an increased risk of neonatal hypoglycemia and other neonatal morbidities. To date, there has only been one randomized controlled trial to test the effectiveness and safety of sulfonylurea therapy (glyburide [glibenclamide]) in the management of women with GDM. Both the insulin- and glyburide-treated women were able to achieve satisfactory glucose control and had similar perinatal outcomes. Glyburide was not detected in the cord serum of any infant in the glyburide group. In summary, based on the currently available data, it appears that glyburide could be safely and effectively utilized in the management of GDM. However, more intensive investigation regarding the safety and feasibility of oral agents in pregnancies complicated by type 2 diabetes is necessary. It is important to emphasize that it is the level of metabolic control achieved and not the mode of therapy that is crucial to improving outcomes in these pregnancies.

Maternal metabolic control and perinatal outcome in women with gestational diabetes treated with regular or lispro insulin: comparison with non-diabetic pregnant women

OBJECTIVE

To compare maternal glucose levels and neonatal outcome, achieved in women with gestational diabetes (GDM) receiving either regular insulin or insulin lispro, with those of a control group of non-diabetic pregnant women.

STUDY DESIGN

We enrolled 49 pregnant women with GDM, randomly allocated to the treatment with either insulin lispro (n=25) or regular insulin (n=24), and 50 pregnant women with normal GCT, matched for age, parity, pre-pregnancy weight and BMI, who formed the control group. All the women were caucasian, non-obese, with a singleton pregnancy and delivered term live born infants. Women of both groups were requested to perform a blood glucose profile (consisting of nine determinations: fasting/pre-prandial, 1 and 2h post-prandial) every week from the time of diagnosis to 38 weeks (study subgroups) or every 2 weeks from 28 to 38 weeks' gestation (control group).

RESULTS

Overall pre-prandial blood glucose values in diabetic women were significantly higher than those of controls; at the 1h post-prandial time point, blood glucose values of GDM women receiving insulin lispro were similar to those of controls, whereas in the regular group they were significantly higher. Overall, both the lispro and regular insulin obtained optimal metabolic control at the 2h post-prandial time point, although near-normal blood glucose levels 2h after lunch could be observed only in the lispro group. There were no statistically significant differences between the groups in neonatal outcome and anthropometric characteristics; however, the rate of infants with a cranial-thoracic circumference (CC/CT) ratio between the 10th and the 25th percentile was significantly higher in the group treated with regular insulin in comparison to the lispro and control groups.

CONCLUSIONS

Fasting/pre-prandial and 1h post-prandial maternal blood glucose levels in non-diabetic pregnant women fell well below the currently accepted criteria of glycemic normality in diabetic pregnancies. In women with GDM, the use of insulin lispro enabled the attainment of near-normal glucose levels at the 1h post-prandial time point and was associated with normal anthropometric characteristics; the use of regular insulin was not able to blunt the 1h peak post-prandial response to a near-normal extent and resulted in infants with a tendency toward the disproportionate growth. Insulin lispro can be regarded as a valuable option for the treatment of gestational diabetes.

Oral hypoglycemic agents and the pregnant diabetic: "from bench to bedside"

Today, the criteria for diagnosis and treatment have evolved into an evidence-based medicine approach. The need for evidence-based information is especially critical in the management of gestational diabetes, in general, and especially in the use of oral hypoglycemic agents. These agents have been categorically contraindicated for decades in the United States based on anecdotal and/or weak evidence for these recommendations. In this article, the similarities between gestational and type 2 diabetes are described and the rationale for the use of oral hypoglycemic agents for the treatment of both are discussed. The author will show how research from basic sciences (placental transfers) to clinical studies (perinatal outcome) can lead to significant evidence on which to base management recommendations.

Audit of maternal and fetal outcomes in women treated for glucose intolerance during pregnancy

OBJECTIVE

To determine whether one should aim for glycaemia that is statistically 'normal' or for levels of glycaemia low enough to prevent macrosomia (if such a threshold exists) when glucose intolerance is detected during pregnancy.

DESIGN

An audit of pregnancy outcomes in women with impaired glucose tolerance in pregnancy as compared to a local age-matched reference group with normal glucose tolerance.

RESULTS

Our study suggests that for most patients, more intensive therapy would not have been justified. Maternal smoking appeared to convey some 'advantages' in terms of neonatal outcomes, with reduction in large-for-gestational-age (LGA) infants and jaundice in babies of impaired glucose tolerance (IGT) mothers.

CONCLUSIONS

These observations demonstrate the importance of considering risk factors other than GTT results in analysing pregnancy outcomes, while emphasising that 'normalisation' of fetal size should not be our only therapeutic endpoint. Our detailed outcome review allows us to reassure patients with GDM that with current treatment protocols, they should have every expectation of a positive pregnancy outcome.