Point: yes, it is necessary to rely entirely on glycemic values for the insulin treatment of all gestational diabetic women

Different methods and settings for glucose monitoring for gestational diabetes during pregnancy

BACKGROUND

Incidence of gestational diabetes mellitus (GDM) is increasing worldwide. Blood glucose monitoring plays a crucial part in maintaining glycaemic control in women with GDM and is generally recommended by healthcare professionals. There are several different methods for monitoring blood glucose which can be carried out in different settings (e.g. at home versus in hospital).

OBJECTIVES

The objective of this review is to compare the effects of different methods and settings for glucose monitoring for women with GDM on maternal and fetal, neonatal, child and adult outcomes, and use and costs of health care.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (30 September 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-randomised controlled trials (qRCTs) comparing different methods (such as timings and frequencies) or settings, or both, for blood glucose monitoring for women with GDM.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias, and extracted data. Data were checked for accuracy.We assessed the quality of the evidence for the main comparisons using GRADE, for:- primary outcomes for mothers: that is, hypertensive disorders of pregnancy; caesarean section; type 2 diabetes; and- primary outcomes for children: that is, large-for-gestational age; perinatal mortality; death or serious morbidity composite; childhood/adulthood neurosensory disability;- secondary outcomes for mothers: that is, induction of labour; perineal trauma; postnatal depression; postnatal weight retention or return to pre-pregnancy weight; and- secondary outcomes for children: that is, neonatal hypoglycaemia; childhood/adulthood adiposity; childhood/adulthood type 2 diabetes.

MAIN RESULTS

We included 11 RCTs (10 RCTs; one qRCT) that randomised 1272 women with GDM in upper-middle or high-income countries; we considered these to be at a moderate to high risk of bias. We assessed the RCTs under five comparisons. For outcomes assessed using GRADE, we downgraded for study design limitations, imprecision and inconsistency. Three trials received some support from commercial partners who provided glucose meters or financial support, or both. Main comparisons Telemedicine versus standard care for glucose monitoring (five RCTs): we observed no clear differences between the telemedicine and standard care groups for the mother, for:- pre-eclampsia or pregnancy-induced hypertension (risk ratio (RR) 1.49, 95% confidence interval (CI) 0.69 to 3.20; 275 participants; four RCTs; very low quality evidence);- caesarean section (average RR 1.05, 95% CI 0.72 to 1.53; 478 participants; 5 RCTs; very low quality evidence); and- induction of labour (RR 1.06, 95% CI 0.63 to 1.77; 47 participants; 1 RCT; very low quality evidence);or for the child, for:- large-for-gestational age (RR 1.41, 95% CI 0.76 to 2.64; 228 participants; 3 RCTs; very low quality evidence);- death or serious morbidity composite (RR 1.06, 95% CI 0.68 to 1.66; 57 participants; 1 RCT; very low quality evidence); and- neonatal hypoglycaemia (RR 1.14, 95% CI 0.48 to 2.72; 198 participants; 3 RCTs; very low quality evidence).There were no perinatal deaths in two RCTs (131 participants; very low quality evidence). Self-monitoring versus periodic glucose monitoring (two RCTs): we observed no clear differences between the self-monitoring and periodic glucose monitoring groups for the mother, for:- pre-eclampsia (RR 0.17, 95% CI 0.01 to 3.49; 58 participants; 1 RCT; very low quality evidence); and- caesarean section (average RR 1.18, 95% CI 0.61 to 2.27; 400 participants; 2 RCTs; low quality evidence);or for the child, for:- perinatal mortality (RR 1.54, 95% CI 0.21 to 11.24; 400 participants; 2 RCTs; very low quality evidence);- large-for-gestational age (RR 0.82, 95% CI 0.50 to 1.37; 400 participants; 2 RCTs; low quality evidence); and- neonatal hypoglycaemia (RR 0.64, 95% CI 0.39 to 1.06; 391 participants; 2 RCTs; low quality evidence). Continuous glucose monitoring system (CGMS) versus self-monitoring of glucose (two RCTs): we observed no clear differences between the CGMS and self-monitoring groups for the mother, for:- caesarean section (RR 0.91, 95% CI 0.68 to 1.20; 179 participants; 2 RCTs; very low quality evidence);or for the child, for:- large-for-gestational age (RR 0.67, 95% CI 0.43 to 1.05; 106 participants; 1 RCT; very low quality evidence) and- neonatal hypoglycaemia (RR 0.79, 95% CI 0.35 to 1.78; 179 participants; 2 RCTs; very low quality evidence).There were no perinatal deaths in the two RCTs (179 participants; very low quality evidence). Other comparisons Modem versus telephone transmission for glucose monitoring (one RCT): none of the review's primary outcomes were reported in this trial Postprandial versus preprandial glucose monitoring (one RCT): we observed no clear differences between the postprandial and preprandial glucose monitoring groups for the mother, for:- pre-eclampsia (RR 1.00, 95% CI 0.15 to 6.68; 66 participants; 1 RCT);- caesarean section (RR 0.62, 95% CI 0.29 to 1.29; 66 participants; 1 RCT); and- perineal trauma (RR 0.38, 95% CI 0.11 to 1.29; 66 participants; 1 RCT);or for the child, for:- neonatal hypoglycaemia (RR 0.14, 95% CI 0.02 to 1.10; 66 participants; 1 RCT).There were fewer large-for-gestational-age infants born to mothers in the postprandial compared with the preprandial glucose monitoring group (RR 0.29, 95% CI 0.11 to 0.78; 66 participants; 1 RCT).

AUTHORS' CONCLUSIONS

Evidence from 11 RCTs assessing different methods or settings for glucose monitoring for GDM suggests no clear differences for the primary outcomes or other secondary outcomes assessed in this review.However, current evidence is limited by the small number of RCTs for the comparisons assessed, small sample sizes, and the variable methodological quality of the RCTs. More evidence is needed to assess the effects of different methods and settings for glucose monitoring for GDM on outcomes for mothers and their children, including use and costs of health care. Future RCTs may consider collecting and reporting on the standard outcomes suggested in this review.

Timing of peak blood glucose after breakfast meals of different glycemic index in women with gestational diabetes

This study aims to determine the peak timing of postprandial blood glucose level (PBGL) of two breakfasts with different glycemic index (GI) in gestational diabetes mellitus (GDM). Ten women with diet-controlled GDM who were between 30 and 32 weeks of gestation were enrolled in the study. They consumed two carbohydrate controlled, macronutrient matched bread-based breakfasts with different GI (low vs. high) on two separate occasions in a random order after an overnight fast. PBGLs were assessed using a portable blood analyser. Subjects were asked to indicate their satiety rating at each blood sample collection. Overall the consumption of a high GI breakfast resulted in a greater rise in PBGL (mean ± SEM peak PBGL: low GI 6.7 ± 0.3 mmol/L vs. high GI 8.6 ± 0.3 mmol/L; p < 0.001) and an earlier peak PBGL time (16.9 ± 4.9 min earlier; p = 0.015), with high variability in PBGL time between subjects. There was no significant difference in subjective satiety throughout the test period. In conclusion, the low GI breakfast produced lower postprandial glycemia, and the peak PBGL occurred closer to the time recommended for PBGL monitoring (i.e., 1 h postprandial) in GDM than a macronutrient matched high GI breakfast.

Recent advances in the treatment of gestational diabetes

Despite four decades of research there is a lack of international consensus on the screening, diagnosis, treatment and follow up of gestational diabetes mellitus (GDM). Currently, GDM is managed by diet modification, exercise and exogenous human insulin. During the last decade, several insulin analogues and oral antihyperglycaemic drugs have revolutionised the management of diabetes mellitus in non-pregnant women. Most of these recent drugs still remain investigational in GDM due to concerns about their safety in pregnancy. This review will focus primarily on the pharmacological treatment of GDM. It will objectively assess the value of these exciting new drugs in pregnancy as they could potentially benefit every woman with GDM.

Management of diabetes mellitus by obstetrician-gynecologists

OBJECTIVE

To compare practice patterns of the American College of Obstetrician and Gynecologists (ACOG) Fellows for the diagnosis and treatment of gestational diabetes mellitus (GDM) and type 1 diabetes mellitus with current ACOG recommendations and prior published series.

METHODS

We sent a questionnaire to 1,398 practicing ACOG Fellows and Junior Fellows, 398 of whom comprise the Collaborative Ambulatory Research Network. Responses were evaluated by age and sex to assess differences in practice.

RESULTS

Younger physicians were more likely to treat pregnant patients. Ninety-six percent of obstetricians routinely screen for GDM, nearly all by using a 50-g glucose 1-hour oral test. Nearly 60% of respondents establish the diagnosis of GDM using the National Diabetes Data Group criteria. In addition to medical nutrition therapy, almost 75% of respondents recommend exercise for patients with GDM. Approximately 60% of respondents reported that all of their patients with GDM self-monitor their blood glucose. When medical nutrition therapy is ineffective for their patients with GDM, 82% of respondents initially prescribe insulin, whereas 13% begin with glyburide. Nearly 75% of respondents routinely perform a postpartum evaluation of glucose tolerance in the patient with GDM. Most obstetricians manage the glucose control of their patients with type 1 diabetes mellitus themselves.

CONCLUSION

Practicing obstetrician-gynecologists have incorporated recent recommendations into their practice patterns for both GDM and type 1 diabetes mellitus, including patients' self-monitoring of blood glucose, exercise, and postpartum testing in GDM.

LEVEL OF EVIDENCE

III