Reference intervals for hemoglobin A1c in pregnant women: data from an Italian multicenter study

13. Management of Diabetes in Pregnancy: Standards of Medical Care in Diabetes-2018

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

The utility of HbA1c combined with haematocrit for early screening of gestational diabetes mellitus

AIMS

To evaluate the utility of glycated haemoglobin A1c (HbA1c) alone and in combination with haematocrit (HCT) for screening gestational diabetes mellitus (GDM) between 12-16 gestational weeks.

METHODS

This prospective study was carried out in the Obstetrics and Gynaecology Hospital of Fudan University from November 2014 to February 2015. In total, 690 pregnant women between 20 and 35 years old were included in this study. All subjects received a routine blood examination for HbA1c and HCT at 12-16 gestational weeks (gw) and a 75-g oral glucose tolerance test at 24-28 gw. Threshold values for the diagnosis of GDM were a plasma glucose concentration of 5.1 mmol/L after fasting, 10.0 mmol/L at 60 min, and 8.5 mmol/L at 120 min. Receiver operating characteristic curves were used to evaluate the diagnostic performance of HbA1c with or without HCT.

RESULTS

One hundred seven women were diagnosis with GDM at 24-28 gw. An HbA1c cutoff value < 4.55% at 12-16 gw showed adequate sensitivity to exclude GDM (85.0%) but low specificity (17.3%), while an HbA1c cutoff value ≥ 5.25% presented adequate specificity (96.6%) but low sensitivity (13.3%) in diagnosing GDM. The area under the receiver operating characteristic curve for HbA1c (12-16 gw) detection of GDM was 0.563 (95% confidence interval [CI], 0.50-0.625). When combined HbA1c with HCT ( > 38.8%) for the screening of GDM, the area under the receiver operating characteristic curve was 0.604 (95% [CI] 0.509, 0.701).

CONCLUSIONS

Whether the adoption of HbA1c as a screening test for GDM would benefit pregnant women remains to be determined. However, combining HbA1c with HCT for the screening of GDM may be a useful tool to predict GDM.

The diagnostic value of glycated albumin in gestational diabetes mellitus

PURPOSE

Our objective was to compare the diagnostic performance of glycated hemoglobin (HbA1c), GA, and fasting plasma glucose (FPG) for the diagnosis of GDM.

METHODS

Women at their late second or early third trimesters seen from October 2011 to April 2012 were studied. GDM was diagnosed based on oral glucose tolerance test results, and GA and HbA1c were measured at the same time. Patients were divided into two groups (with and without GDM), and areas under the receiver-operating characteristic curves (AUCs) were calculated to determine the diagnostic value of FPG, GA, and HbA1c.

RESULTS

A total of 698 women were included, of which 232 (33.2%) had GDM. Overall, FPG had the highest AUC for the detection of GDM, and was significantly higher than that of GA (0.692 vs. 0.568, p < 0.001) and HbA1c (0.692 vs. 0.619, p = 0.014). The AUC of FPG was significantly greater than that of GA and HbA1c. At 24-28 weeks' gestation, the AUCs of FPG were significantly greater than those of GA and HbA1c.

CONCLUSIONS

These results do not support the use of GA as a screening tool for GDM.

Effect of iron supplementation on HbA1c levels in pregnant women with and without anaemia

BACKGROUND

Iron deficiency anaemia has been associated with higher HbA1c levels. However, during and after iron supplementation there is a decrease in HbA1c results, causing a misinterpretation. Our aim was to analyse the effect of iron supplementation on HbA1c levels in nondiabetic pregnant women with and without anaemia.

METHODS

Pregnant women in prenatal care, without gestational diabetes (GDM) or previous diabetes mellitus (DM) that performed an oral glucose tolerance test (OGTT) in the third trimester of pregnancy were invited to participate. Clinical and laboratorial analyses were performed, including standardized questionnaire, OGTT, full blood count and HbA1c.

RESULTS

A total of 231 pregnant women without DM or GDM were included in the study. According to anaemia and/or iron supplementation, we divided women in: no iron and no anaemia - Group 1 (N=86); no iron and with anaemia - Group 2 (N=29); iron and no anaemia - Group 3 (N=87); iron and anaemia - Group 4 (N=29). There was statistically a significant, although no clinically relevant, difference between HbA1c values in pregnant women in Groups 1 and 4 [5.1±0.4% (32±4.4mmol/mol) and 4.8±0.3% (29±3.3mmol/mol), P<0.01; respectively]. HbA1c values in pregnant women in Groups 1, 2 and 3 were similar, independently of anaemia [5.1±0.4% (32±4.4mmol/mol); 5.0±0.4% (31±4.4mmol/mol) and 5.0±0.4% (31±4.4mmol/mol); p>0.05; respectively].

CONCLUSIONS

Iron supplementation during pregnancy does not affect HbA1c levels and has no clinical impact in the final interpretation of results in the absence of anaemia or presence of mild anaemia. Interpreting HbA1c results in pregnant women during iron therapy and with moderate or severe anaemia still requires caution.

The care of pregestational and gestational diabetes and drug metabolism considerations

INTRODUCTION

Normal pregnancy development involves gradual decline in insulin sensitivity, which sometimes requires pharmacotherapy. Insulin is the drug of choice for gestational and pregestational diabetes. Metabolism of traditional insulins results in inadequate onset and duration of action and marked peak activity. These properties increase risk of excessive glucose excursions, which are especially undesirable during pregnancy. Insulin analogs have been emerging as a safer and more effective treatment of diabetes during pregnancy. Areas covered: This manuscript reviews currently used antihyperglycemic agents: fast and long-acting insulins, metformin and glyburide. Trials demonstrating their efficacy and safety during pregnancy are described. Certain drug metabolism considerations (e.g. affinity to IGF-1) are emphasized. Expert opinion: The theories that insulin analogs bind to immunoglobulin and cross placenta have been disproved. Lispro, aspart, glargine and detemir do not transfer across the placenta and do not result in adverse maternal and neonatal outcomes. In addition, favorable pharmacokinetic profiles (rapid onset and 24-hour near peakless activity) substantially reduce blood glucose variability including hypoglycemia. We believe that insulin analogs should be given strong consideration for the treatment of diabetes during pregnancy. Metformin has also proven to be safe and may be considered as an initial single agent for milder gestational diabetes.

Associations between gestational diabetes mellitus and elevated HbA1c early postpartum in a multi-ethnic population

AIMS

To investigate the prevalence of elevated HbA_1c 14 weeks postpartum in different ethnic groups and in women with and without gestational diabetes mellitus (GDM) in the index pregnancy and to explore demographic and biological factors from early pregnancy associated with elevated HbA_1c (HbA_1c ≥5.7% (≥39mmol/mol)) postpartum.

METHODS

From a cohort study in Oslo, Norway, we included 570 pregnant women, examined in gestational week 15, 28, and 14 weeks postpartum. The association between elevated HbA_1c and demographic and biological factors were assessed by logistic regression analyses.

RESULTS

The prevalence of elevated HbA_1c postpartum was 23% in the total population, 15% among Western Europeans and 28% among women with ethnic minority background (p<0.01). In ethnic minorities elevated HbA_1c was found in 39% of women with recent GDM diagnosed by the World Health Organization 2013 criteria and in 21% of women without GDM (p<0.01), compared to 22% and 13% in Western Europeans (p=0.11). We found independent associations between elevated HbA_1c and ethnic minority background (OR 2.0, 95% CI 1.27, 3.18), and GDM (OR 2.04, 95% CI 1.35, 3.10) (p<0.01).

CONCLUSIONS

The prevalence of elevated HbA_1c postpartum was 23%, and significantly higher among women with ethnic minority background irrespective of GDM.

Early Pregnancy Biochemical Predictors of Gestational Diabetes Mellitus

PURPOSE OF REVIEW

Universal oral glucose tolerance-based screening is employed to identify pregnant women with gestational diabetes mellitus (GDM), as treatment of this condition decreases the risk of associated complications. A simple and accurate blood test which identifies women at low or high risk for GDM in the first trimester would have the potential to decrease costs and improve outcomes through prevention or treatment. This review summarizes published data on early pregnancy biomarkers which have been tested as predictors of GDM.

RECENT FINDINGS

A large number of first-trimester biochemical predictors of GDM have been reported, mostly in small case-control studies. These include glycemic markers (fasting glucose, post-load glucose, hemoglobin A1C), inflammatory markers (C-reactive protein, tumor necrosis factor-alpha), insulin resistance markers (fasting insulin, sex hormone-binding globulin), adipocyte-derived markers (adiponectin, leptin), placenta-derived markers (follistatin-like-3, placental growth factor, placental exosomes), and others (e.g., glycosylated fibronectin, soluble (pro)renin receptor, alanine aminotransferase, ferritin). A few large studies suggest that first-trimester fasting glucose or hemoglobin A1C may be useful for identifying women who would benefit from early GDM treatment. To translate the findings from observational studies of first-trimester biomarkers for GDM to clinical practice, trials or cost-effectiveness analyses of screening and treatment strategies based on these novel biomarkers are needed.

Is There a Role for HbA1c in Pregnancy?

Outside pregnancy, HbA1c analysis is used for monitoring, screening for and diagnosing diabetes and prediabetes. During pregnancy, the role for HbA1c analysis is not yet established. Physiological changes lower HbA1c levels, and pregnancy-specific reference ranges may need to be recognised. Other factors that influence HbA1c are also important to consider, particularly since emerging data suggest that, in early pregnancy, HbA1c elevations close to the reference range may both identify women with underlying hyperglycaemia and be associated with adverse pregnancy outcomes. In later pregnancy, HbA1c analysis is less useful than an oral glucose tolerance test (OGTT) at detecting gestational diabetes. Postpartum, HbA1c analysis detects fewer women with abnormal glucose tolerance than an OGTT, but the ease of testing may improve follow-up rates and combining HbA1c analysis with fasting plasma glucose or waist circumference may improve detection rates. This article discusses the relevance of HbA1c testing at different stages of pregnancy.

Use of Insulin Lispro Protamine Suspension in Pregnancy

Maternal metabolism changes substantially during pregnancy, which poses numerous challenges to physicians managing pregnancy in women with diabetes. Insulin is the agent of choice for glycemic control in pregnant women with diabetes, and the insulin analogs are particularly interesting for use in pregnancy. These agents may reduce the risk of hypoglycemia and promote a more physiological glycemic profile than regular human insulin in pregnant women with type 1 (T1D), type 2 (T2D), or gestational (GDM) diabetes. However, there have been concerns regarding potential risk for crossing the placental barrier, mitogenic stimulation, teratogenicity, and embryotoxicity. Insulin lispro protamine suspension (ILPS), an intermediate- to long-acting insulin, has a stable and predictable pharmacological profile, and appears to have a favorable time–action profile and produce desirable basal and postprandial glycemic control. As the binding of insulin lispro is unaffected by the protamine molecule, ILPS is likely to have the same mitogenic and immunogenic potential as insulin lispro. Insulin lispro produces similar outcomes to regular insulin in pregnant women with T1D, T2D, or GDM, does not cross the placental barrier, and is considered a useful treatment option for pregnant women with diabetes. Clinical data support the usefulness of ILPS for basal insulin coverage in non-pregnant patients with T1D or T2D, and suggest that the optimal regimen, in terms of balance between efficacy and hypoglycemic risk, is a once-daily injection, especially in patients with T2D. Available data concerning use of ILPS in pregnant women are currently derived from retrospective analyses that involved, in total, >1200 pregnant women. These analyses suggest that ILPS is at least as safe and effective as neutral protamine Hagedorn insulin. Thus, available experimental and clinical data suggest that ILPS once daily is a safe and effective option for the management of diabetes in pregnant women.

Funding: Eli Lilly and Company.

HbA1c Test as a Tool in the Diagnosis of Gestational Diabetes Mellitus

Aims

Gestational diabetes mellitus (GDM) is a prevalent and potentially serious condition which may put both mothers and neonates at risk. The current recommendation for diagnosis is the oral glucose tolerance test (OGTT). This study aimed to determine the usefulness of HbA1c test as a diagnostic tool for GDM as compared to the traditional criteria based on the OGTT.

Methods

This was a diagnostic test accuracy study. We performed OGTT and HbA1c test in women attending prenatal visits at a tertiary hospital. GDM was defined according to WHO1999 or ADA/WHO 2013 criteria. ROC curve was used to evaluate the diagnostic performance of HbA1c. Sensitivity, specificity and likelihood ratios for different HbA1c cut-off points were calculated.

Results

Of the 262 women in the third trimester of gestation enrolled in the study, 86 (33%) were diagnosed with GDM. Only five of these women presented HbA1c ≥48 mmol/mol (6.5%). This cut-off point presented 100% specificity but very low sensitivity (7%). Based on ROC curve, and considering OGTT as the reference criterion, HbA1c ≥40 mmol/mol (5.8%) showed adequate specificity in diagnosing GDM (94.9%) but low sensitivity (26.4%). Unlike, HbA1c values of 31 mmol/mol (5.0%) presented adequate sensitivity (89.7%) but low specificity (32.6%) to detect GDM. For women with HbA1c ≥40 mmol/mol (5.8%), the positive and negative likelihood ratios were 5.14 (95%CI 2.49–10.63) and 0.78 (0.68–0.88), respectively. The post-test probability of GDM was about 40%, representing a 4.0-fold increase in the mean pre-test probability. This cut-off point could eliminate the need for the unpleasant and laborious OGTT tests in almost one third of cases, as 38% of patients with GDM may be diagnosable by HbA1c test alone.

Conclusions

Our results show that combined HbA1c and OGTT measurements may be useful in diagnosing GDM.

Obese Nondiabetic Pregnancies and High Maternal Glycated Hemoglobin at Delivery as an Indicator of Offspring and Maternal Postpartum Risks: The Prospective PEACHES Mother-Child Cohort

BACKGROUND

We investigated whether obese pregnant women negative for gestational diabetes (GDM) still experience dysglycemia, as indicated by high glycated hemoglobin (Hb A1c) at delivery, and whether this impacts offspring and long-term maternal outcomes.

METHODS

Data of 462 mother-child pairs of our prospective Programming of Enhanced Adiposity Risk in Childhood - Early Screening (PEACHES) cohort study were analyzed. Of 885 obese and normal-weight pregnancies prospectively enrolled after GDM testing according to the International Association of Diabetes and Pregnancy Study Groups criteria, 462 GDM-negative mothers and their offspring were investigated. We assessed associations of maternal Hb A1c at delivery with large-for-gestational-age (LGA) birth weights, cord-blood C-peptide, and biomarkers of glucose metabolism and inflammation in obese mothers followed for 2.9 years (median) postpartum (n = 42).

RESULTS

Cumulative distribution analysis in GDM-negative normal-weight women (n = 155) revealed that 12% had Hb A1c ≥5.7% at delivery (high Hb A1c). Among obese GDM-negative women (n = 307), 31.9% (95% CI, 26.7%-37.4%) equaled or exceeded this cutoff. In obese GDM-negative women with Hb A1c ≥5.7% (n = 98) vs <5.7% (n = 209) at delivery, newborns were more likely to be born LGA [adjusted odds ratio 3.56 (95% CI, 1.64-8.02)], and mean cordblood serum C-peptide was increased by 0.09 ng/mL (95% CI, 0.01-0.17 ng/mL). In the mothers at follow-up, mean postpartum Hb A1c, fasting glucose, high-sensitivity C-reactive protein, and fibrinogen concentrations were higher by 0.3% (95% CI, 0.1%-0.5%), 6.0 mg/dL (95% CI, 2.4-9.5 mg/dL), 6.8 mg/L (95% CI, 1.4-12.3 mg/L), and 74.9 mg/dL (95% CI, 13.6-136.2 mg/dL), respectively.

CONCLUSIONS

Increased Hb A1c in obese GDM-negative women at delivery indicates gestational dysglycemia, potentially conferring offspring and long-term maternal health risks. These findings should raise awareness as to careful monitoring of obese pregnancies. Measurement of Hb A1c at delivery could help select women who may need closer postpartum health checks.

Lower resting energy expenditure and fat oxidation in Native American and Hispanic infants born to mothers with diabetes

OBJECTIVE

To determine whether exposure to diabetes in utero affects resting energy expenditure (REE) and fuel oxidation in infants.

STUDY DESIGN

At 35 ± 5 days after birth, body composition and REE were measured in full-term offspring of Native American and Hispanic women with either well-controlled diabetes (13 girls, 11 boys) or normal healthy pregnancies (18 girls, 17 boys).

RESULTS

Control of dysglycemia during gestation in the women with diabetes mellitus met current clinical standards, shown by average glycated hemoglobin (5.9 ± 0.2%; 40.6 ± 2.3 mmol/mol). Infant body mass (offspring of women with diabetes: 4.78 ± 0.13, control offspring: 4.56 ± 0.08 kg) and body fatness (offspring of women with diabetes: 25.2 ± 0.6, control offspring: 24.2 ± 0.5 %) did not differ between groups. REE, adjusted for lean body mass, was 14% lower in offspring of women with diabetes (41.7 ± 2.3 kJ/h) than control offspring (48.6 ± 2.0, P = .025). Fat oxidation was 26% lower in offspring of women with diabetes (0.54 ± 0.05 g/h) than control offspring (0.76 ± 0.04, P < .01) but carbohydrate oxidation did not differ. Thus, fat oxidation accounted for a lower fraction of REE in the offspring of women with diabetes (49 ± 4%) than control offspring (60 ± 3%, P = .022). Mothers with diabetes were older and had higher prepregnancy body mass index than control mothers.

CONCLUSIONS

Well-controlled maternal diabetes did not significantly affect body mass or composition of offspring at 1-month old. However, infants with mothers with diabetes had reduced REE and fat oxidation, which could contribute to adiposity and future disease risk. Further studies are needed to assess the impact differences in age and higher prepregnancy body mass index.

Association of pre-pregnancy BMI and postpartum weight retention with postpartum HbA1c among women with Type 1 diabetes

AIM

To examine the association of pre-pregnancy BMI and postpartum weight retention with postpartum HbA(1c) levels in women with Type 1 diabetes.

METHODS

We longitudinally evaluated 136 women with Type 1 diabetes who received prenatal, pregnancy, and postpartum care through Joslin Diabetes Center's Diabetes and Pregnancy Program between 2004 and 2009. Weight, BMI and HbA(1c) concentrations were assessed before the index pregnancy and repeatedly monitored after delivery until 12 months postpartum. We used linear mixed models to assess the association of postpartum HbA(1c) with pre-pregnancy BMI and postpartum weight retention.

RESULTS

The mean HbA(1c) concentration increased from 49 mmol/mol (6.6%) at 6 weeks postpartum to 58 mmol/mol (7.5%) by 10 months postpartum, a level similar to the mean pre-pregnancy HbA(1c) concentration. Postpartum weight retention showed a linearly decreasing trend of 0.06 kg/week (P < 0.0001), with -0.1 kg average postpartum weight retention by 1 year postpartum. Compared with women with a pre-pregnancy BMI ≥ 25 kg/m², women with a lower pre-pregnancy BMI maintained a 3.4 mmol/mol (0.31%) lower HbA(1c) concentration, after adjusting for several sociodemographic, reproductive and diabetes-related factors (P = 0.03). There was a suggestion of a time-varying positive association between HbA1c and postpartum weight retention, with the most significant difference of 3.7 mmol/mol (0.34%; P = 0.05) at 30 weeks postpartum among women with postpartum weight retention ≥ 5 kg vs those with postpartum weight retention < 5 kg.

CONCLUSIONS

Pre-pregnancy BMI and postpartum weight retention were positively associated with HbA(1c) during the first postpartum year in women with Type 1 diabetes. Interventions to modify the behaviours associated with these body weight factors before pregnancy and after delivery may help women with Type 1 diabetes maintain good glycaemic control after pregnancy.

An early pregnancy HbA1c ≥5.9% (41 mmol/mol) is optimal for detecting diabetes and identifies women at increased risk of adverse pregnancy outcomes

OBJECTIVE

Pregnant women with undiagnosed diabetes are a high-risk group that may benefit from early intervention. Extrapolating from nonpregnancy data, HbA1c ≥6.5% (48 mmol/mol) is recommended to define diabetes in pregnancy. Our aims were to determine the optimal HbA1c threshold for detecting diabetes in early pregnancy as defined by an early oral glucose tolerance test (OGTT) at <20 weeks' gestation and to examine pregnancy outcomes relating to this threshold.

RESEARCH DESIGN AND METHODS

During 2008-2010 in Christchurch, New Zealand, women were offered an HbA1c measurement with their first antenatal bloods. Pregnancy outcome data were collected. A subset completed an early OGTT, and HbA1c performance was assessed using World Health Organization criteria.

RESULTS

HbA1c was measured at a median 47 days' gestation in 16,122 women. Of those invited, 974/4,201 (23%) undertook an early OGTT. In this subset, HbA1c ≥5.9% (41 mmol/mol) captured all 15 cases of diabetes, 7 with HbA1c <6.5% (<48 mmol/mol). This HbA1c threshold was also 98.4% (95% CI 97-99.9%) specific for gestational diabetes mellitus (GDM) before 20 weeks (positive predictive value = 52.9%). In the total cohort, excluding women referred for GDM management, women with HbA1c of 5.9-6.4% (41-46 mmol/mol; n = 200) had poorer pregnancy outcomes than those with HbA1c <5.9% (<41 mmol/mol; n = 8,174): relative risk (95% CI) of major congenital anomaly was 2.67 (1.28-5.53), preeclampsia was 2.42 (1.34-4.38), shoulder dystocia was 2.47 (1.05-5.85), and perinatal death was 3.96 (1.54-10.16).

CONCLUSIONS

HbA1c measurements were readily performed in contrast to the low uptake of early OGTTs. HbA1c ≥5.9% (≥41 mmol/mol) identified all women with diabetes and a group at significantly increased risk of adverse pregnancy outcomes.

Glycation of fetal hemoglobin reflects hyperglycemia exposure in utero

OBJECTIVE

The lifetime risk of metabolic diseases in offspring of women with gestational diabetes mellitus (GDM) depends, at least in part, on the impact of glycemic fetal programming. To quantify this impact, we have developed and validated a unique mass spectrometry method to measure the percentage of glycated hemoglobin in cord blood.

RESEARCH DESIGN AND METHODS

This case-control study includes 37 GDM women and 30 pregnant women with normal glucose tolerance (NGT).

RESULTS

Glycation of the α-chain (Glα) was higher in neonates from GDM (2.32 vs. 2.20%, P < 0.01). Glα strongly correlated with maternal A1C measured at delivery in the overall cohort (r = 0.67, P < 0.0001) as well as in each group (GDM: r = 0.66, P < 0.0001; NGT: r = 0.50, P = 0.01).

CONCLUSIONS

Thus, Glα may reflect hyperglycemic exposure during the last weeks of fetal development. Future studies will confirm Glα is a predictive biomarker of prenatally programmed lifetime metabolic health and disease.

[Sources of error when using haemoglobin A1c]

BACKGROUND

Measurement of glycated haemoglobin A1 in whole blood (b-HbA1c) can be used in both diagnosing and following up patients with diabetes. Correct interpretation of analytical results is contingent on agreement between average plasma glucose (p-glucose) and b-HbA1c. This article provides an overview of factors that may result in a discrepancy between average glucose concentration and b-HbA1c.

METHOD

Literature search in PubMed to identify scientific articles that describe strengths and weaknesses of b-HbA1c.

RESULTS

The b-HbA1c reading usually provides a good picture of average p-glucose for the preceding two to three months. Patients who are being treated with iron/vitamin B12 supplements, have liver failure, haemolytic anaemia or bleeding usually have a lower b-HbA1c than their p-glucose level would suggest. With increasing patient age, B12 deficiency or iron deficiency anaemia, higher values of b-HbA1c are seen for the same p-glucose level. Some ethnic groups have a higher b-HbA1c than their average p-glucose would suggest, but the risk of long-term complications appears generally to be more closely associated with b-HbA1c than with the glucose level. Pregnancy, renal failure or haemoglobinopathies may make the b-HbA1c value unreliable as an expression of average p-glucose.

INTERPRETATION

Correct interpretation of b-HbA1c is conditional on the requisitioner being aware of possible sources of error. If the patient is suspected to have a condition that leads to lack of consistency between b-HbA1c and average p-glucose, glucose-based criteria must be used in diagnosing diabetes.

HbA1c levels in patients with gestational diabetes mellitus: Relationship with pre-pregnancy BMI and pregnancy outcome

BACKGROUND/AIMS

The use of glycated hemoglobin (HbA1c) measurement in gestational diabetes mellitus (GDM) is controversial. Aim of the present study was to determine HbA1c levels in a series of GDM patients, in order to verify the possible contribution of HbA1c to GDM management.

MATERIALS/SUBJECTS AND METHODS

The study included 148 caucasian GDM patients. GDM screening was performed between the 24th and the 28th week of gestation by a two-step procedure, according to the 4th and 5th International Workshop Conference on Gestational Diabetes Mellitus recommendations. Exclusion criteria were: preexisting diabetes, corticosteroid therapy, history of asthma or hypertension, known fetal anomaly, history of previous stillbirth, preterm delivery considered to be likely for either maternal disease or fetal conditions. HBA1c was determined by a standard HPLC technique.

RESULTS

At GDM diagnosis, all HbA1c levels were ≤ 6% and the greatest frequency (71/148; 48.0%) of HbA1c values resulted in the range 5.0-5.3%. This frequency increased to 54% before delivery. A significant correlation between HbA1c values at GDM diagnosis and individual BMI prior to conception was observed. The proportion of pregnancies presenting negative outcomes increased progressively with increasing HbA1c levels, from 6.2% (1/16) for HbA1c levels <5% to 18.3% (13/71) for HbA1c 5.0-5.3%, to 37.8% (17/45) in patients with HBA1c levels 5.4-5.6%, to 56.2% (9/16) for HbA1c levels >5.6%. ROC analysis showed that HbA1c at diagnosis and before delivery resulted a good predictor of adverse pregnancy outcome.

CONCLUSIONS

The present results indicate that HbA1c levels could be of help in predicting adverse pregnancy events.

Glucose Fluctuations during Gestation: An Additional Tool for Monitoring Pregnancy Complicated by Diabetes

Continuous glucose monitoring (CGM) gives a unique insight into magnitude and duration of daily glucose fluctuations. Limited data are available on glucose variability (GV) in pregnancy. We aimed to assess GV in healthy pregnant women and cases of type 1 diabetes mellitus or gestational diabetes (GDM) and its possible association with HbA1c. CGM was performed in 50 pregnant women (20 type 1, 20 GDM, and 10 healthy controls) in all three trimesters of pregnancy. We calculated mean amplitude of glycemic excursions (MAGE), standard deviation (SD), interquartile range (IQR), and continuous overlapping net glycemic action (CONGA), as parameters of GV. The high blood glycemic index (HBGI) and low blood glycemic index (LBGI) were also measured as indicators of hyperhypoglycemic risk. Women with type 1 diabetes showed higher GV, with a 2-fold higher risk of hyperglycemic spikes during the day, than healthy pregnant women or GDM ones. GDM women had only slightly higher GV parameters than healthy controls. HbA1c did not correlate with GV indicators in type 1 diabetes or GDM pregnancies. We provided new evidence of the importance of certain GV indicators in pregnant women with GDM or type 1 diabetes and recommended the use of CGM specifically in these populations.

Predictors of large and small for gestational age birthweight in offspring of women with gestational diabetes mellitus

AIM

To identify predictors of large and small for gestational age in women with gestational diabetes mellitus.

METHODS

A retrospective audit of clinical data analysed for singleton births in women diagnosed with gestational diabetes by Australasian Diabetes in Pregnancy Society guidelines from 1994 to 2009. Exclusions were: incomplete data, delivered at < 36 weeks gestation and/or last recorded weight > 4 weeks pre-delivery. We assessed: pre-pregnancy BMI, ethnicity, total maternal weight gain, weight gain before and after treatment initiation for gestational diabetes, HbA(1c) at gestational diabetes presentation and treatment modality (diet or insulin) and smoking. Birthweight was assessed using customized percentile charts (large for gestational age > 90th; small for gestational age < 10th percentile). Multiple regression analyses were undertaken; statistical significance was p < 0.05.

RESULTS

There were 1695 women first seen at (mean ± sd) 28.1 ± 5.3 weeks gestation (range 6-39). Ethnic mix was South-East Asian 36.7%, Middle Eastern 27.6%, European 22.4%, Indian/Pakistani 8.6%, Samoan 1.9%, African 1.5% and Maori 1.1%. Therapy was diet 69.1% and insulin 30.9%. Mean total weight gain was 12.3 ± 6.1 kg, the majority (10.6 ± 6.0 kg), gained before dietary intervention. There were 7.9% small for gestational age and 15.2% large for gestational age births. Significant independent large for gestational age predictors were: weight gain before intervention, pre-pregnancy BMI, weight gain after intervention and treatment type, but not HbA1c or smoking. Significant small for gestational age predictors were: weight gain before intervention, weight gain after intervention, but not pre-pregnancy BMI, HbA(1c) or smoking.

CONCLUSION

Conventional treatment for gestational diabetes mellitus concentrates on management of blood glucose levels. The trends identified here emphasize the need to also address pregnancy weight gain stratified by pre-pregnancy BMI.

Diagnostic accuracy of glycosylated hemoglobin in chinese patients with gestational diabetes mellitus: a meta-analysis based on 2,812 patients and 5,918 controls

BACKGROUND AND AIMS

The accuracy of glycosylated hemoglobin (HBA1c) detection for the diagnosis of gestational diabetes mellitus (GDM) has been extensively studied in the Chinese population, but the exact role of these detections remains controversial. The present meta-analysis was performed to establish the overall accuracy of HBA1c for the diagnosis of Chinese patients with GDM.

METHODS

After a systematic review of related studies, the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and other measures about the accuracy of HBA1c in the diagnosis of GDM were pooled using random-effects models. The summary receiver operating characteristic (SROC) curve analysis was used to summarize the overall test performance.

RESULTS

Forty-one studies included 2812 Chinese patients with GDM and 5918 controls were included in our meta-analysis. The summary estimates for HBA1c in the diagnosis of GDM in the studies included were as follows: sensitivity 0.762 (95% confidence interval [CI]: 0.746-0.777), specificity 0.917 (95% CI: 0.910-0.924), PLR 8.21 (95% CI: 3.77-17.89), NLR 0.20 (95% CI: 0.09-0.44), and DOR 41.40 (95% CI: 11.47-149.38). Our data showed that the SROC curve is positioned near the desirable upper left corner of the SROC curve, while the area under curve (AUC) was 0.93 with a Q* value of 0.865.

CONCLUSIONS

Measurement of HBA1c is likely to be a useful diagnostic tool for confirming GDM. The results of HBA1c should be interpreted in parallel with clinical findings and the results of conventional tests.

Managing type 1 diabetes mellitus in pregnancy--from planning to breastfeeding

Type 1 diabetes mellitus in pregnant women increases the risk of adverse outcomes for mother and offspring. Careful preconception counselling and screening is important, with particular focus on glycaemic control, indications for antihypertensive therapy, screening for diabetic nephropathy, diabetic retinopathy and thyroid dysfunction, as well as review of other medications. Supplementation with folic acid should be initiated before conception in order to minimize the risk of fetal malformations. Obtaining and maintaining tight control of blood glucose and blood pressure before and during pregnancy is crucial for optimizing outcomes; however, the risk of severe hypoglycaemia during pregnancy is a major obstacle. Although pregnancy does not result in deterioration of kidney function in women with diabetic nephropathy and normal serum creatinine levels, pregnancy complications such as pre-eclampsia and preterm delivery are more frequent in these women than in women with T1DM and normal kidney function. Rapid-acting insulin analogues are considered safe to use in pregnancy and studies on long-acting insulin analogues have provided reassuring results. Immediately after delivery the insulin requirement declines to approximately 60% of the prepregnancy dose, and remains 10% lower than before pregnancy during breastfeeding.

Utility of HbA1c for diagnosis of gestational diabetes mellitus

OBJECTIVE

To evaluate the utility of HbA(1c) in combination with OGTT for diagnosis of GDM.

MATERIALS AND METHODS

607 pregnant women with their estimated gestational age between 24 and 28 weeks were evaluated for GDM using OGTT based on ADA criteria. HbA(1c) was also done at the same time.

RESULTS

The mean HbA(1c) value in women with GDM was significantly higher than women without GDM (5.73 ± 0.34% compared to 5.34 ± 0.35%). The area under ROC curve of HbA(1c) to detect GDM was 0.805 and an HbA(1c) cutoff value of ≥5.95% had sensitivity of 28.6% and specificity of 97.2% in diagnosing GDM while an HbA(1c) cutoff value of ≥5.45% had sensitivity of 85.7% and specificity of 61.1% in diagnosing GDM. For women with an HbA(1c) value between 5.45% and 5.95%, an OGTT should be performed to correctly identify women with GDM. Using this methodology 85.7% of the GDM cases would have been detected and only 2.8% of normal women would have been wrongly labeled as having GDM. Also, this methodology would have obviated an OGTT in 61.8% women in our study.

CONCLUSION

HbA(1c) in combination with OGTT can obviate the need of OGTT in almost two-thirds of women with GDM.

Antenatal haemoglobin A1c and risk of large-for-gestational-age infants in a multi-ethnic cohort of women with gestational diabetes

Gestational diabetes mellitus (GDM) is a risk factor for delivering a large-for-gestational-age (LGA) infant. Haemoglobin A1c (A1C) is an indicator of glycaemic control. The objective of this study was to test whether higher A1C quartile at the time of diagnosis of GDM is associated with increased risk of delivering a LGA or macrosomic infant. Women with singleton pregnancies treated for GDM at a large diabetes and pregnancy programme located in Charlotte, North Carolina, were eligible for inclusion in this retrospective cohort study. Clinical information, including A1C at diagnosis, treatment, prior medical and obstetric history, and birth data were abstracted from medical records. LGA was defined as birthweight >90th percentile for gestational age and sex and macrosomia as birthweight >4000 g. Logistic regression was used to analyse the association of A1C at GDM diagnosis with risk of delivering LGA or macrosomic infants. This study included 502 women. Prevalences of LGA and macrosomia were 4% and 6% respectively. After adjustment there was no detectable trend of increased risk for LGA (P for trend = 0.12) or macrosomia (P for trend = 0.20) across increasing quartiles of A1C at GDM diagnosis. A1C at GDM diagnosis may not be linearly associated with LGA or macrosomia, possibly because of the mediating effect of strict glycaemic control in this clinical setting.

Hemoglobin A1c and postpartum abnormal glucose tolerance among women with gestational diabetes mellitus

OBJECTIVE

To analyze the association of hemoglobin A1c (HbA1c) at gestational diabetes mellitus (GDM) diagnosis with postpartum abnormal glucose in a cohort of women with GDM.

METHODS

Women with singleton pregnancies treated for GDM at a large diabetes and pregnancy program located in Charlotte, North Carolina, who completed a postpartum 2-hour oral glucose tolerance test were eligible for inclusion in this retrospective cohort study. Clinical information, including maternal HbA1c at diagnosis, was abstracted from medical records. A parametric survival model was used to assess the association of HbA1c at GDM diagnosis with postpartum maternal abnormal glucose including impaired fasting glucose, impaired glucose tolerance, and any postpartum abnormal glucose.

RESULTS

Of the 277 postpartum women with GDM, 75 (32%) had impaired fasting glucose, 61 (28%) had impaired glucose tolerance, and 15 (9%) were diagnosed with type 2 diabetes mellitus after delivery. After adjustment for clinic, maternal age, parity, prepregnancy body mass index 25 or higher, nonwhite race or ethnicity, and gestational week at first HbA1c, we detected a trend of increased risk for impaired fasting glucose (P=.01), impaired glucose tolerance (P=.002), and any glucose abnormality (P<.001) associated with increased quartile of HbA1c at GDM diagnosis.

CONCLUSION

Hemoglobin A1c measured at GDM diagnosis may be a useful tool for identifying patients with GDM at highest risk of developing postpartum abnormal glucose.

What do we need beyond hemoglobin A1c to get the complete picture of glycemia in people with diabetes?

Hemoglobin A1c (HbA1c) is currently the most commonly used marker for the determination of the glycemic status in people with diabetes and it is frequently used to guide therapy and especially medical treatment of people with diabetes. The measurement of HbA1c has reached a high level of analytical quality and, therefore, this biomarker is currently also suggested to be used for the diagnosis of diabetes. Nevertheless, it is crucial for people with diabetes and their treating physicians to be aware of possible interferences during its measurement as well as physiological or pathological factors that contribute to the HbA1c concentration without being related to glycemia, which are discussed in this review. We performed a comprehensive review of the literature based on PubMed searches on HbA1c in the treatment and diagnosis of diabetes including its most relevant limitations, glycemic variability and self-monitoring of blood glucose (SMBG). Although the high analytical quality of the HbA1c test is widely acknowledged, the clinical relevance of this marker regarding risk reduction of cardiovascular morbidity and mortality is still under debate. In this respect, we argue that glycemic variability as a further risk factor should deserve more attention in the treatment of diabetes.

HbA1c in pregnancy

During pregnancy, the glucose levels vary according to the hormonal changes and the metabolic needs necessary to maintain fetal nutrition but strict glycemic control is essential to minimize the maternal and fetal morbidity and mortality of pregnancies complicated by diabetes. Although considered the "gold standard" for diagnosis, measurement of glucose in the blood is subject to several limitations, many of which are not widely appreciated. Measurement of A1c for diagnosis is appealing as with one number, a total, integrated view of glycemia over time is derived though it has some inherent limitations. Thus, supplementation with HbA1c, as is common outside pregnancy, seems appropriate. Before pregnancy, the target for metabolic control in women with diabetes is HbA1c values near the normal range. However, the upper normal range of HbA1c during normal pregnancy is only sparsely investigated with different methods though recently a number of papers have been published regarding the determination of reference ranges for HbA1c in pregnancy. These changes may have clinical implications for the assessment and management of glycemic control in diabetic pregnancy and calls for establishment of separate reference limits of HbA1c levels in different trimesters as compared to general population.

A pilot study on dietary approaches in multiethnicity: two methods compared

Background. Medical nutritional therapy is the most important method for normalizing glucose levels in pregnancy. In this setting, there is a new problem to consider relating to migrants, their personal food preferences, and ethnic, cultural, and religious aspects of their diet. We compared maternal and fetal outcomes between two multiethnic groups of pregnant women, one adopting a food plan that included dishes typical of the foreign women's original countries (the "ethnic meal plan" group), while the other group adopted a standard meal plan. Findings. To develop the meal plan, each dish chosen by the women was broken down into its principal ingredients. The quantity of each food was given in tablespoons, teaspoons, slices, and cups, and there were photographs of the complete dish. The group treated with the ethnic meal plan achieved a better metabolic control at the end of the pregnancy and a lower weight gain (though the difference was not statistically significant). As for fetal outcome, the group on the ethnic meal plan had babies with a lower birth weight and there were no cases of macrosomia or LGA babies. Conclusions. This preliminary study indicates the positive effect of an ethnic approach to diet on the outcome of pregnancy.

Determination of reference intervals of glycated albumin and hemoglobin A1c in healthy pregnant Japanese women and analysis of their time courses and influencing factors during pregnancy

Glycemic control is an important issue in gestational diabetes mellitus (GDM) and in diabetic pregnant women. We determined the reference intervals of glycated albumin (GA) and hemoglobin A1c (HbA1c) as glycemic control markers in healthy Japanese pregnant women and analyzed their time courses and factors that influence these variables during pregnancy. 676 women were screened for the present study. After the exclusion of non-pregnant and puerperal women, 574 women were studied to determine the reference intervals. HbA1c, GA, casual plasma glucose, urinary glucose, urinary protein, and body mass index (BMI) (non-pregnancy) were measured. HbA1c levels significantly decreased in the second trimester of pregnancy and increased in the third trimester, while GA levels significantly decreased towards the third trimester. Casual plasma glucose levels decreased in the first trimester and subsequently remained constant. The reference intervals of GA and HbA1c in the healthy pregnant women were 11.5-15.7% and 4.5-5.7%, respectively. GA levels were lower (p<0.01) and HbA1c levels were higher (p<0.05) in pregnant women with proteinuria. In the obese group, GA levels were lower (p<0.01) than those of the control group (18.5≤ BMI <25kg/m²), and HbA1c levels were higher (p<0.01) than those of the control group. On the basis of the results of this multicenter study, the reference intervals of GA and HbA1c in healthy Japanese pregnant women were determined. Strict glycemic control is essential to reduce perinatal complications. GA appears to be a useful marker for pregnant women, since it can be measured easily and changes rapidly and markedly.

Is there a relationship between mean blood glucose and glycated hemoglobin?

Measurement of hemoglobin A1c (HbA1c) is considered the gold standard for monitoring chronic glycemia of diabetes patients. Hemoglobin A1c indicates an average of blood glucose levels over the past 3 months. Its close association with the risk for the development of long-term complications is well established. However, HbA1c does not inform patients about blood glucose values on a daily basis; therefore, frequent measurements of blood glucose levels are necessary for the day-to-day management of diabetes. Clinicians understand what HbA1c means and how it relates to glucose, but this is not the case with patients. Therefore, the translation of the HbA1c results into something more familiar to patients seemed a necessity. The scope of this article is to review the literature to search for enough scientific evidence to support the idea of a close relationship between HbA1c and mean blood glucose (MBG), and to justify the translation of HbA1c into something that reflects the MBG. Most studies confirm a close relationship between HbA1c and MBG, although different studies result in different linear equations. Factors affecting this relationship may limit the usefulness and applicability of a unique mathematical equation to all diabetes populations.

New International Association of the Diabetes and Pregnancy Study Groups (IADPSG) recommendations for diagnosing gestational diabetes compared with former criteria: a retrospective study on pregnancy outcome

AIMS

The International Association of the Diabetes and Pregnancy Study Groups (IADPSG) Consensus Panel recommends new criteria for diagnosing gestational diabetes. We evaluated the clinical and metabolic characteristics, and pregnancy outcome, in women previously classifiable as 'normal' according to the 4th International Workshop Conference on gestational diabetes criteria, but reclassified as 'abnormal' according to the new recommendations.

METHODS

Using the new IADPSG criteria, 3953 pregnancies were retrospectively reclassified as 1815 women with normal glucose tolerance and 2138 with gestational diabetes, 112 (2.8%) of whom would have been classified as normal according to the older criteria.

RESULTS

Of the 2138 women classified as abnormal by the new criteria, the 112 women now reclassified as abnormal were younger and had a lower pre-pregnancy BMI than the 2026 women who had also been classified as abnormal by the previous criteria. The 100-g oral glucose tolerance test showed significantly higher glucose levels in these 112 women than in the 1815 women reclassified as normal (P < 0.0001). Caesarean section was significantly more frequent (P < 0.01) and the ponderal index for the newborn significantly higher in these reclassified women than in those classified as normal (P < 0.0001), and their basal glucose levels correlated significantly with the ponderal index (P < 0.05).

CONCLUSION

The new criteria for diagnosing gestational diabetes identified a group of women previously classifiable as normal according to the 4th International Workshop Conference criteria, but revealing metabolic characteristics and pregnancy outcomes resembling those of women who would have been considered to have gestational diabetes by the previous criteria.

The general use of glycated haemoglobin for the diagnosis of diabetes and other categories of glucose intolerance: still a long way to go

Glycated haemoglobin (HbA(1c)) is considered the 'gold standard' for monitoring metabolic control in diabetes. An International Expert Committee recently recommended HbA(1c) as a better method than measurement of glucose to use in the diagnosis of diabetes, based on its strong association with microvascular complications, a lower day-to-day variability and ease of use, not necessarily in the fasting state. These recommendations have been embraced by the American Diabetes Association (ADA), which stated in its Standards of Medical Care in Diabetes 2010 that "A(1c), fasting plasma glucose or the 2 h 75 g oral glucose tolerance test (OGTT) are appropriate for testing diabetes and assessing the risk of future diabetes," and that "a confirmed A(1c) ≥ 6.5% is diagnostic for diabetes." Measuring HbA(1c) has several advantages over glucose measurements, but its exclusive use should only be considered if the test is conducted under standardised conditions and its limitations are taken into due account. The impact of its use on the epidemiology of diabetes and other categories of glucose intolerance, as seen from recent reports, is also discussed.

Pregnancy outcome in immigrant women with gestational diabetes mellitus

Recent studies show adverse outcomes of pregnancy among immigrant women from countries with high diabetes rates. We compared maternal and fetal outcomes in immigrant and Italian women with gestational diabetes mellitus (GDM) followed up at our center. Maternal characteristics considered were age, pre-pregnancy body mass index (BMI), HbA1c, frequency of insulin treatment, timing and mode of delivery, and hypertensive disorders; and, for fetal outcome, infants large or small for gestational age, and fetal complications. Pre-pregnancy BMI and HbA1c were higher in immigrant GDM women than in Italians, and more of them were on insulin. No differences in maternal outcome emerged between the two groups. More large for gestational age (LGA) babies were born to immigrant women than to Italians, but no other differences emerged. Apart from newborn LGA, maternal and fetal outcomes were comparable in our immigrant and Italian GDM women. Immigrant GDM women have favourable outcomes if given access to health care and language and cultural barriers are removed.

Antepartum A1C, maternal diabetes outcomes, and selected offspring outcomes: an epidemiological review

Between 1989 and 2004, the prevalence of gestational diabetes mellitus (GDM) in the United States increased by 122%. Glycated haemoglobin, as measured by haemoglobin A1C (A1C), can potentially identify pregnant women at high risk for adverse outcomes associated with GDM including macrosomia and post-partum glucose intolerance. Our objective was to systematically review the literature with respect to A1C levels during pregnancy and associated maternal and offspring outcomes. We used MEDLINE to identify relevant publications from 1975 to 2009. We included articles if they met the following criteria: original full text articles in English; primary exposure of antepartum A1C; women with GDM at baseline or who developed GDM during the study; primary outcome of GDM, insulin use, post-partum abnormal glucose or type 2 diabetes (T2DM), birthweight, macrosomia or large for gestational age. Case series and case reports were excluded. Twenty studies met our criteria. A1C at GDM diagnosis was positively associated with post-partum abnormal glucose. Women with post-partum T2DM or impaired glucose tolerance had mean A1C at GDM diagnosis higher than those with normal post-partum glucose (P ≤ 0.002) and a 1% increase in A1C at GDM diagnosis was associated with 2.36 times higher odds of post-partum abnormal glucose 6 weeks after delivery [95% confidence interval 1.19, 4.68]. The association of A1C and birthweight varied substantially between studies, with correlation coefficients ranging from 0.11 to 0.51. A1C, a less burdensome and costly measure than an oral glucose tolerance test, appears to be an attractive measure for identifying women at high risk of adverse outcomes associated with GDM.

Pregnancy complicated by diabetes: what is the best level of HbA1c for conception?

To reduce the congenital malformations that occur in pregnancies complicated by diabetes, it is essential to achieve and maintain a good metabolic control before conception. In this context, measuring HbA1c is considered as the gold standard for monitoring metabolic control in diabetes and various different HbA1c levels have been recommended as optimal in the preconception period for diabetic women planning a pregnancy. An analysis of key studies published on this issue until now clearly shows that HbA1c levels correlate closely with the occurrence of congenital malformations and other neonatal complications characteristic of pregnant diabetic women. HbA1c is therefore one of the key markers to use in monitoring metabolic control, and the most reasonable approach would seem to be to use a standardized measurement method and aim for HbA1c levels resembling normal values as closely as possible, with a view to preventing episodes of hypoglycemia.

Dysglycemias in pregnancy: from diagnosis to treatment. Brazilian consensus statement

There is an urgent need to find consensus on screening, diagnosing and treating all degrees of dysglycemia that may occur during pregnancies in Brazil, considering that many cases of dysglycemia in pregnant women are currently not diagnosed, leading to maternal and fetal complications. For this reason the Brazilian Diabetes Society (SBD) and the Brazilian Federation of Gynecology and Obstetrics Societies (FEBRASGO), got together to introduce this proposal. We present here a joint consensus regarding the standardization of clinical management for pregnant women with any degree of dysglycemia, on the basis of current information, to improve medical assistance and to avoid related complications of dysglycemia in pregnancy to the mother and the fetus. This consensus aims to standardize the diagnosis among general practitioners, endocrinologists and obstetricians allowing the dissemination of information in basic health units, public and private services, that are responsible for screening, diagnosing and treating disglycemic pregnant patients.

Management of gestational diabetes mellitus

The incidence of gestational diabetes mellitus (GDM) is on the increase and, if not diagnosed, managed and treated adequately, can have unfavorable maternal and fetal outcomes. Several studies have shown that glycemic values considered as adequate in the past when monitoring GDM failed to contain these adverse outcomes and randomized trials are needed to ascertain whether these targets should be lowered. Dietary restrictions remain the mainstay of GDM management and suitable physical exercise can help too. The use of rapid-acting insulin analogues (lispro and aspart) are novel treatments for improving metabolic control by reducing postprandial glycemia, while long-acting insulin analogues need to be evaluated by further studies for safety in clinical use before they can be prescribed. Numerous studies have found glyburide and metformin safe in women with GDM but more randomized controlled trials are needed, with a long-term follow-up of mother and child, to confirm these results.

Macrosomia in well controlled CSII treated Type I diabetic pregnancy

OBJECTIVE

To survey the effect of tight glycemic control by insulin pumps, of pre-gestational Type 1 diabetic women on pregnancy outcome.

METHODS

Twelve consecutive Type 1, insulin pump treated, diabetic patients followed in the high risk maternal - fetal clinic were ascertained. Data regarding glucose control was assessed and correlated with pregnancy outcome.

RESULTS

A total of 14 deliveries (10 singleton) were assessed. There were no miscarriages, one baby that was born with a ventricular septal defect (VSD). Glycemic control was within the acceptable guidelines. HbA1c (%) by trimesters: 6.5 +/- 0.9, 5.9 +/- 0.7, 5.8 +/- 0.6 and average glucose (mg/dL) 121.0 +/- 15.2, 114.8 +/- 13.2, 116.0 +/- 21.1. Average birth weight was 3312.1 +/- 750.2 g with five babies (35%) weighting over 4.0 kg at birth. Birth weight was significantly correlated with HbA1c at the first trimester, mean glucose at trimester 1 and 2, and maternal weight at delivery (r = 0.74, p = 0.045; r = 0.72, p = 0.051; r = 0.74, p = 0.046; r = 0.74, p = 0.04, respectively).

CONCLUSIONS

Our study of a limited number of patients suggest that women with pre-gestational diabetes obtaining acceptable glycemic goals with insulin pump therapy have increased risk of macrosomia. Current glycemic goals and therapies in treating pre-gestational diabetic patients therefore might not be sufficient to normalise pregnancy outcomes in of women with pre-gestational diabetes.

Elevated third-trimester haemoglobin A 1c predicts preterm delivery in type 1 diabetes

The prevalence of preterm delivery is considerably elevated in women with type 1 diabetes. The aim of the study was to evaluate haemoglobin A(1c) (HbA(1c)) as a predictor of preterm delivery. Two hundred thirteen consecutive pregnant women with type 1 diabetes and normal urinary albumin excretion were included prospectively. HbA(1c) was analyzed at 10, 20 and 28 weeks of gestation. Seventy-one women (33%) delivered pre term and 142 at term. At 10 weeks of gestation, HbA(1c) was 7.3% (S.D. 1.0) vs. 6.9% (S.D. 0.9) (P<.01), at 20 weeks of gestation 6.6% (S.D. 0.7) vs. 6.1% (S.D. 0.7) (P<.001) and at 28 weeks of gestation 6.7% (S.D. 0.8) vs. 6.1% (S.D. 0.7) (P<.001). When comparing HbA(1c) at 10, 20 and 28 weeks of gestation, HbA(1c) at 28 weeks of gestation (P<.001) was the best predictor of preterm delivery. The adjusted odds ratio per 1% increment in HbA(1c) at 28 weeks of gestation was 2.8 (95% CI 1.7-4.4). HbA(1c) at 28 weeks of gestation was a clinical significant predictor of preterm delivery in type 1 diabetes.