Longitudinal changes in the continuous glucose profile measured by the CGMS in healthy pregnant women and determination of cut-off values

Third trimester re-screening for gestational diabetes in morbidly obese women despite earlier negative test can reveal risks for obstetrical complications

AIM

We investigated associations of maternal obesity with late gestational diabetes mellitus (GDM) diagnosis (>34 weeks) in women with previous normal glucose screening, and associations of late GDM with obstetrical outcomes.

METHODS

This retrospective cohort study assessed obstetrical and neonatal outcomes of 238 women with normal (24-28 week) glucose screening results, who underwent late repeat oral glucose tolerance tests (OGTT) (>34 weeks) due to a suspected LGA fetus (54.6%) or polyhydramnios (45.4%). A sub-analysis was performed of outcomes of women with late versus mid-trimester GDM.

RESULTS

The GDM rate in repeat OGTT screening was 22.2% for the total sample, and 33% among women with morbid obesity. Among women with late GDM versus without late GDM, rates were higher for macrosomia, large-for-gestational-age fetus induction of labor, neonatal hypoglycemia, jaundice, and the need for phototherapy. Among women with late GDM, a higher pregestational BMI was associated with adverse maternal and perinatal outcomes. Higher risks for macrosomia and CS due to macrosomia were demonstrated in women with late vs. mid-trimester GDM.

CONCLUSION

Late screening in pregnancy may reveal GDM among women with previous normal glucose screening, particularly among those with late third trimester BMI ≥ 35 kg/m² , GDM in a previous pregnancy or fasting glucose >95 mg/dl. Women diagnosed with GDM at >34 weeks following normal glucose screening at 24-28 weeks are at higher risk for adverse perinatal outcomes. For women with morbid obesity, or suspected macrosomia or polyhydramnios in the late third trimester, and normal glucose screening in the second trimester, retesting should be considered.

Longitudinal changes in glucose during pregnancy in women with gestational diabetes risk factors

AIMS/HYPOTHESIS

Despite recommendations to screen women with diabetes risk factors for hyperglycaemia in the first trimester, criteria for normal glucose values in early pregnancy have not been firmly established. We aimed to compare glucose levels in early pregnancy with those later in gestation and outside of pregnancy in women with diabetes risk factors.

METHODS

In pregnant women (N = 123) followed longitudinally through the postpartum period, and a separate cohort of non-pregnant women (N = 65), we performed 75 g oral glucose tolerance tests. All participants had one or more risk factors for diabetes. Using linear regression, we tested for differences in glucose levels between non-pregnant and pregnant women at early (7-15 weeks) and mid-late (24-32 weeks) gestation as well as postpartum, with adjustment for maternal age, parity, marital status and BMI. In a longitudinal analysis using mixed-effects models, we tested for differences in glucose levels across early and mid-late pregnancy compared with postpartum. Differences are expressed as β (95% CI).

RESULTS

Fasting glucose was lower in pregnant compared with non-pregnant women by 0.34 (0.18, 0.51) mmol/l (p < 0.0001) in early pregnancy and by 0.45 (0.29, 0.61) mmol/l (p < 0.0001) in mid-late pregnancy. In longitudinal models, fasting glucose was lower by 0.13 (0.04, 0.21) mmol/l (p = 0.003) in early pregnancy and by 0.16 (0.08, 0.25) mmol/l (p = 0.0003) in mid-late pregnancy compared with the same women postpartum. Early pregnancy post-load glucose levels did not differ from those in non-pregnant women or the same women postpartum. In mid-late pregnancy, compared with non-pregnant women, elevations in 1 h post-load glucose level (0.60 [-0.12, 1.33] mmol/l, p = 0.10) and 2 h post-load glucose (0.49 [-0.21, 1.19] mmol/l, p = 0.17) were not statistically significant. However, in longitudinal analyses, 1 h and 2 h post-load glucose levels were higher in mid-late pregnancy (by 0.78 [0.35, 1.21] mmol/l, p = 0.0004, and 0.67 [0.30, 1.04] mmol/l, p = 0.0005, respectively) when compared with postpartum.

CONCLUSIONS/INTERPRETATION

In women with diabetes risk factors, fasting glucose declines in the first trimester. Post-load glucose increases later in pregnancy. These findings may inform criteria for diagnosing hyperglycaemia early in pregnancy.

Early Gestational Diabetes Mellitus: Diagnostic Strategies and Clinical Implications

Preexisting diabetes mellitus (DM) should be ruled out early in pregnancy in those at risk. During screening, a significant proportion of women do not reach the threshold for overt DM but fulfill the criteria used for diagnosing conventional gestational DM (cGDM). There is no consensus on the management of pregnancies with intermediate levels of hyperglycemia thus diagnosed. We have used the term early gestational DM (eGDM) for this condition and reviewed the currently available literature. Fasting plasma glucose (FPG), oral glucose tolerance test, and glycated hemoglobin (HbA1c) are the commonly employed screening tools in early pregnancy. Observational studies suggest that early pregnancy FPG and Hba1c correlate with the risk of cGDM and adverse perinatal outcomes. However, specific cut-offs, including those proposed by the International Association of the Diabetes and Pregnancy Study Group, do not reliably predict the development of cGDM. Emerging data, though indicate that FPG ≥ 92 mg/dL (5.1 mmol/L), even in the absence of cGDM, signals the risk for perinatal complication. Elevated HbA1c, especially a level ≥ 5.9%, also correlates with the risk of cGDM and worsened outcome. HbA1c as a diagnostic test is however besieged with the usual caveats that occur in pregnancy. The studies that explored the effects of intervention present conflicting results, including a possibility of fetal malnutrition and small-for-date baby in the early treatment group. Diagnostic thresholds and glycemic targets in eGDM may differ, and large multicenter randomized controlled trials are necessary to define the appropriate strategy.

GLU: a software package for analysing continuously measured glucose levels in epidemiology

Continuous glucose monitors (CGM) record interstitial glucose levels 'continuously', producing a sequence of measurements for each participant (e.g. the average glucose level every 5 min over several days, both day and night). To analyse these data, researchers tend to derive summary variables such as the area under the curve (AUC), to then use in subsequent analyses. To date, a lack of consistency and transparency of precise definitions used for these summary variables has hindered interpretation, replication and comparison of results across studies. We present GLU, an open-source software package for deriving a consistent set of summary variables from CGM data. GLU performs quality control of each CGM sample (e.g. addressing missing data), derives a diverse set of summary variables (e.g. AUC and proportion of time spent in hypo-, normo- and hyper- glycaemic levels) covering six broad domains, and outputs these (with quality control information) to the user. GLU is implemented in R and is available on GitHub at https://github.com/MRCIEU/GLU. Git tag v0.2 corresponds to the version presented here.

Longitudinal Changes in the Relationship Between Hemoglobin A1c and Glucose Tolerance Across Pregnancy and Postpartum

OBJECTIVE

To characterize the relationship between hemoglobin A1c (HbA1c) levels and glucose tolerance across pregnancy and postpartum.

DESIGN AND PARTICIPANTS

In a longitudinal study of pregnant women with gestational diabetes risk factors (N = 102), we performed oral glucose tolerance testing (OGTT) and HbA1c measurements at 10-15 weeks of gestation, 24-30 weeks of gestation (N = 73), and 6-24 weeks postpartum (N = 42). Complete blood counts were obtained from clinical records. We calculated HbA1c-estimated average glucose levels and compared them with mean OGTT glucose levels (average of fasting, 1- and 2-hour glucose levels). Linear mixed effects models were used to test for longitudinal changes in measurements.

RESULTS

Mean OGTT glucose increased between 10-15 and 24-30 weeks of gestation (β = 8.1 mg/dL, P = .001), while HbA1c decreased during the same time period (β = -0.13%, P < .001). At 10-15 weeks of gestation and postpartum the discrepancy between mean OGTT glucose and HbA1c-estimated average glucose was minimal (mean [standard deviation]: 1.2 [20.5] mg/dL and 0.16 [18.1] mg/dL). At 24-30 weeks of gestation, the discrepancy widened (13.2 [17.9] mg/dL, β = 12.7 mg/dL, P < .001, compared to 10-15 weeks of gestation, with mean OGTT glucose being higher than HbA1c-estimated average glucose). Lower hemoglobin at 24-30 weeks of gestation was associated with a greater discrepancy (β = 6.4 mg/dL per 1 g/dL lower hemoglobin, P = .03 in an age- and gestational age-adjusted linear regression model).

CONCLUSIONS

HbA1c accurately reflects glycemia in the 1st trimester, but underestimates glucose intolerance in the late 2nd trimester. Lower hemoglobin level is associated with greater underestimation. Accounting for gestational age and maternal hemoglobin may improve the clinical interpretation of HbA1c levels during pregnancy.

Difference in the prevalence of gestational diabetes mellitus according to gestational age at 75-g oral glucose tolerance test in Japan: The Japan Assessment of Gestational Diabetes Mellitus Screening trial

AIMS/INTRODUCTION

To evaluate the differences in the results of 75-g oral glucose tolerance tests (OGTTs) according to gestational age in Japan.

MATERIALS AND METHODS

In this prospective cohort study, 2,578 pregnant women were divided into three categories based on their gestational age during the 75-g OGTT: <14 weeks' gestation, 14-23 weeks' gestation and 24-32 weeks' gestation. The association between gestational age and the results of the 75-g OGTT were evaluated using multivariable analysis.

RESULTS

Early gestational age was associated with high fasting plasma glucose levels at the time of the 75-g OGTT, and low corresponding 1-h and 2-h plasma glucose levels. Compared with women with a gestational age of 24-32 weeks, women who had undergone the 75-g OGTT at <14 weeks' gestation had significantly higher odds of gestational diabetes mellitus diagnosis based on the currently used criteria in Japan (adjusted odds ratio 1.42, 95% confidence interval 1.07-1.90).

CONCLUSIONS

The results of the 75-g OGTT varied by gestational age. The use of the same 75-g OGTT cut-off values for the diagnosis of gestational diabetes mellitus, regardless of gestational age, might lead to increases in the prevalence of gestational diabetes mellitus diagnosis in Japan.

Research Gaps in Gestational Diabetes Mellitus: Executive Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop

The National Institute of Diabetes and Digestive and Kidney Diseases convened a workshop on research gaps in gestational diabetes mellitus (GDM) with a focus on 1) early pregnancy diagnosis and treatment and 2) pharmacologic treatment strategies. This article summarizes the proceedings of the workshop. In early pregnancy, the appropriate diagnostic criteria for the diagnosis of GDM remain poorly defined, and an effect of early diagnosis and treatment on the risk of adverse outcomes has not been demonstrated. Despite many small randomized controlled trials of glucose-lowering medication treatment in GDM, our understanding of medication management of GDM is incomplete as evidenced by discrepancies among professional society treatment guidelines. The comparative effectiveness of insulin, metformin, and glyburide remains uncertain, particularly with respect to long-term outcomes. Additional topics in need of further research identified by workshop participants included phenotypic heterogeneity in GDM and novel and individualized treatment approaches. Further research on these topics is likely to improve our understanding of the pathophysiology and treatment of GDM to improve both short- and long-term outcomes for mothers and their children.

Glycaemic profile in the second and third trimesters of normal pregnancy compared to non-pregnant adult females

Aim

To assess the glycaemic profile and glycaemic variation in the second and third trimesters of normal pregnancies.

Methodology

Healthy pregnant women aged 19-35 years between 24 and 36 weeks of gestation were recruited for ambulatory glucose profile monitoring. A total of 18 women in the second trimester, 15 women in the third trimester and 9 healthy non-pregnant women were recruited providing, respectively, 205 days (19,680 data points), 147 days (14,112 data points) and 100 days (9,600 data points) for analysis.

Results

Mean blood glucose level was 20.2% lower in the second trimester and 10.6% lower in the third trimester than non-pregnant women (p < 0.001). In pregnancy, it took 15 to 20 minutes more to reach peak postprandial blood glucose levels compared to non-pregnant women (p = 0.003). Glycaemic variability was more in the third trimester (p < 0.001).

Conclusion

There is tight blood sugar control along with lower mean blood glucose in healthy pregnant women compared to non-pregnant women. Despite this tight glycaemic control, glycaemic variability is higher during pregnancy.

Is fasting plasma glucose in early pregnancy a better predictor of adverse obstetric outcomes than glycated haemoglobin?

OBJECTIVES

To determine, in a multi-ethnic cohort, the suitability of first-trimester fasting plasma glucose and HbA1c levels in non-diabetic range to identify women without diabetes at increased pregnancy risk.

STUDY DESIGN

A retrospective analysis of a prospective cohort between April 2013 and September 2015. Universal testing for fasting plasma glucose and HbA1c levels at the first antenatal blood sampling was performed and women were screened for gestational diabetes mellitus at 24-28 weeks' gestation. Primary outcomes were macrosomia and pre-eclampsia, and secondary outcomes preterm delivery, Caesarean section and large-for-gestational age. Different fasting plasma glucose and HbA1c cut-off levels were assessed for associations with outcomes.

RESULTS

1,228 pregnancies were included for outcome analysis. After adjustment for potential confounders, no association was found between fasting plasma glucose levels and pregnancy outcomes. Women with an HbA1c ≥5.8% (39.9 mmol/mol) showed an increased risk of macrosomia (OR 2.69, 95% CI 1.16-6.24); an HbA1c ≥5.9% (41 mmol/mol) threshold was independently associated with a three-fold risk of pre-eclampsia (95% CI 1.03-9.9) and an HbA1c ≥6.0% (42.1 mmol/mol) with a four-fold risk of large-for-gestational age (95% CI 1.49-11.07).

CONCLUSIONS

In a multi-ethnic population, first-trimester fasting plasma glucose levels were not a better predictor of pregnancy complications than HbA1c. Further, an early HbA1c ≥5.8% (39.9 mmol/mol) threshold is already associated with an increased risk of macrosomia.

Controversies and Advances in Gestational Diabetes-An Update in the Era of Continuous Glucose Monitoring

Diabetes in pregnancy, both preexisting type 1 or type 2 and gestational diabetes, is a highly prevalent condition, which has a great impact on maternal and fetal health, with short and long-term implications. Gestational Diabetes Mellitus (GDM) is a condition triggered by metabolic adaptation, which occurs during the second half of pregnancy. There is still a lot of controversy about GDM, from classification and diagnosis to treatment. Recently, there have been some advances in the field as well as recommendations from international societies, such as how to distinguish previous diabetes, even if first recognized during pregnancy, and newer diagnostic criteria, based on pregnancy outcomes, instead of maternal risk of future diabetes. These new recommendations will lead to a higher prevalence of GDM, and important issues are yet to be resolved, such as the cost-utility of this increase in diagnoses as well as the determinants for poor outcomes. The aim of this review is to discuss the advances in diagnosis and classification of GDM, as well as their implications in the field, the issue of hyperglycemia in early pregnancy and the role of hemoglobin A1c (HbA1c) during pregnancy. We have looked into the determinants of the poor outcomes predicted by the diagnosis by way of oral glucose tolerance tests, highlighting the relevance of continuous glucose monitoring tools, as well as other possible pathogenetic factors related to poor pregnancy outcomes.

Glucose Profiles in Pregnant Women After a Gastric Bypass : Findings from Continuous Glucose Monitoring

BACKGROUND

The diagnosis of gestational diabetes mellitus (GDM) usually requires an oral glucose tolerance test, but this procedure seems inappropriate after gastric bypass surgery (Roux-en-Y gastric bypass (RYGB)) due to specific altered glycemic responses. We aimed here at describing continuous glucose monitoring (CGM) profile of pregnant women after RYGB.

METHODS

CGM was performed in 35 consecutive pregnant women after RYGB at 26.2 ± 5 weeks of gestation.

RESULTS

After RYGB, pregnant women display high postprandial interstitial glucose (IG) peaks and low IG before and 2 h after meals. The postprandial IG peak is reached early, within 54 ± 9 min. The maximum IG values reach 205 mg/dl, and the percentage of time above 140 mg/dl (6.6 ± 7 %) is similar to what is described in GDM women.

CONCLUSIONS

This study is the first to describe CGM profile in pregnant women after RYGB. CGM features are similar to those of non-pregnant post-RYGB patients, characterized by wide and rapid changes in postprandial IG, and high exposure to hyperglycemia. The exposure to hyperglycemia is similar to what is reported in GDM although the time to postprandial peak is shorter. CGM could be an additional useful approach to screen for glucose intolerance during pregnancy after RYGB.

Masked hypoglycemia in pregnancy

BACKGROUND

Hypoglycemia is a major hindrance for optimal glycemic control in women with gestational diabetes mellitus (GDM) on insulin. In the present study, masked hypoglycemia (glucose <2.77mmol/L for ≥30 min) was estimated in pregnant women using a continuous glucose monitoring (CGM) system.

METHODS

Twenty pregnant women with GDM on insulin (cases) and 10 age-matched euglycemic pregnant women (controls) between 24 and 36 weeks gestation were recruited. Both groups performed self-monitoring of blood glucose (SMBG) and underwent CGM for 72 h to assess masked hypoglycemia. Masked hypoglycemic episodes were further stratified into two groups based on interstitial glucose (2.28-2.77 and ≤2.22 mmol/L).

RESULTS

Masked hypoglycemia was recorded in 35% (7/20) of cases and 40% (4/10) of controls using CGM, with an average of 1.28 and 1.25 episodes per subject, respectively. Time spent at glucose levels between 2.28 and 2.77 mmol/L did not differ between the two groups (mean 114 vs 90 min; P = 0.617), but cases spent a longer time with glucose ≤2.2 mmol/L. Babies born to women with GDM were significantly lighter than those born to controls (2860 vs 3290 g; P = 0.012). There was no significant difference in birth weight within the groups among babies born to women with or without hypoglycemia.

CONCLUSION

Euglycemic pregnant women and those with GDM on insulin had masked hypoglycemia. Masked hypoglycemia was not associated with adverse maternal or fetal outcomes. Therefore, low glucose levels in the hypoglycemic range may represent a physiologic adaptation in pregnancy. This response is exaggerated in women with GDM on insulin.

Correlation of the plasma sphingoid base profile with results from oral glucose tolerance tests in gestational diabetes mellitus

Oral glucose tolerance test (OGTT) is usually insufficient to accurately predict the risk for type 2 diabetes mellitus (T2DM), it is therefore necessary to identify an additional biomarker that would most likely improve the accuracy of OGTT. The current OGTT was performed in 53 volunteers after ingestion of 75 g glucose in 250 ml water to each volunteer. Similarly the sphingoid base profile of these volunteers was explored using liquid-chromatography linked with mass spectrometer (LC-MS) and correlated with the different time-points glucose values of OGTT as well as with total area under the curve (tAUC), incremental area under the curve (iAUC), and positive incremental area under the curve (pAUC). The findings showed that 1-deoxysphinganine (1-deoxySA) was significantly positively correlated with the 1-hour, 2-hour, and 3-hour plasma glucose level as well as with total, incremental, and positive incremental AUC while 1-deoxysphingosine (1-deoxySO) was correlated only with 1-hour, 2-hour glucose levels and tAUC of OGTT. The C18SAdiene was negatively correlated with all-time points glucose values and AUCs followed by negative correlation of C18SO, C16SO and C17SO with 2-hour glucose and tAUC of OGTT. The ratios of 1-deoxySA and 1-deoxySO with respect to C18SAdiene have shown significant correlation with 2-hour and AUCs. These ratios were higher in subjects with gestational diabetes in comparison with normal subjects. These findings underlined that 1-deoxysphingolipids (1-deoxySLs) and their ratios with C18SAdiene could be significantly correlated with the glucose load of OGTT and might be used as predictive biomarkers along with OGTT for the risk assessment of diabetes.

Continuous Glucose Monitoring in Patients with Abnormal Glucose Tolerance during Pregnancy: A Case Series

Abnormal glucose tolerance during pregnancy is associated with perinatal complications. We used continuous glucose monitoring (CGM) in pregnant women with glucose intolerance to achieve better glycemic control and to evaluate the maternal glucose fluctuations. We also used CGM in women without glucose intolerance (the control cases). Furthermore, the standard deviation (SD) and mean amplitude of glycemic excursions (MAGE) were calculated for each case. For the control cases, the glucose levels were tightly controlled within a very narrow range; however, the SD and MAGE values in pregnant women with glucose intolerance were relativity high, suggesting postprandial hyperglycemia. Our results demonstrate that pregnant women with glucose intolerance exhibited greater glucose fluctuations compared with the control cases. The use of CGM may help to improve our understanding of glycemic patterns and may have beneficial effects on perinatal glycemic control, such as the detection of postprandial hyperglycemia in pregnant women.

Estriol blunts postprandial blood glucose rise in male rats through regulating intestinal glucose transporters

Despite increased total food intake in healthy, late-stage pregnant women, their peak postprandial blood sugar levels are normally much lower than the levels seen in healthy nonpregnant women. In this study, we sought to determine whether estriol (E3), an endogenous estrogen predominantly produced during human pregnancy, contributes to the regulation of the postprandial blood glucose level in healthy normal rats. In vivo studies using rats showed that E3 blunted the speed and magnitude of the blood glucose rise following oral glucose administration, but it did not appear to affect the total amount of glucose absorbed. E3 also did not affect insulin secretion, but it significantly reduced the rate of intestinal glucose transport compared with vehicle-treated animals. Consistent with this finding, expression of the sodium-dependent glucose transporter 1 and 2 was significantly downregulated by E3 treatment in the brush-border membrane and basolateral membrane, respectively, of enterocytes. Most of the observed in vivo effects were noticeably stronger with E3 than with 17β-estradiol. Using differentiated human Caco-2 enterocyte monolayer culture as an in vitro model, we confirmed that E3 at physiologically relevant concentrations could directly inhibit glucose uptake via suppression of glucose transporter 2 expression, whereas 17β-estradiol did not have a similar effect. Collectively, these data showed that E3 can blunt the postprandial glycemic surge in rats through modulating the level of intestinal glucose transporters.

Glycemic targets in pregnancies affected by diabetes: historical perspective and future directions

The definition of optimal glycemic control in pregnancies affected by diabetes remains enigmatic. Diabetes phenotypes are heterogeneous. Moreover, fetal macrosomia insidiously occurs even with excellent glycemic control. Current blood glucose (BG) targets (FBG ≤95, 1-h post-prandial <140, 2 h <120 mg/dL) have improved perinatal outcomes, but arguably they have not normalized. The conventional management approach has been to replicate a pattern of glycemia in normal pregnancy. Although these patterns are lower than previously appreciated, a randomized controlled trial (RCT) has never compared current vs. lower glucose targets powered on maternal/fetal outcomes. This paper provides historical context to the current targets by reviewing evidence supporting their evolution. Using lower targets (FBG <90, 1 h <122, 2 h <110, mean BG ≤95 mg/dL) may help normalize outcomes, but phenotypic differences (type 1 vs. type 2 vs. gestational diabetes) might require different glycemic goals. There remains a critical need for well-designed RCTs to confirm optimal glycemic control that minimizes both small for and large for gestational age across pregnancies affected by diabetes.

Changing perspectives in pre-existing diabetes and obesity in pregnancy: maternal and infant short- and long-term outcomes

PURPOSE OF REVIEW

Climbing obesity rates in women have propelled the increasing prevalence of type 2 diabetes mellitus (T2DM) in pregnancy, and an increasing number of women with type 1 diabetes mellitus (T1DM) are also affected by obesity. Increasing recognition that an intrauterine environment characterized by obesity, insulin resistance, nutrient excess, and diabetes may be fueling the obesity epidemic in children has created enormous pressure to re-examine the conventional wisdom of our current approaches.

RECENT FINDINGS

Compelling data in pregnancies complicated by diabetes, in particular those accompanied by insulin resistance and obesity, support a fetal programming effect resulting in increased susceptibility to metabolic disease for the offspring later in life. Recent data also underscore the contribution of obesity, lipids, and lesser degrees of hyperglycemia on fetal fat accretion, challenging the wisdom of current gestational weight gain recommendations with and without diabetes. The risks of adverse pregnancy outcomes in T2DM are at least as high as in T1DM and there remains controversy about the ideal glucose treatment targets, the benefit of different insulin analogues, and the role of continuous glucose monitoring in T1DM and T2DM.

SUMMARY

It has become unmistakably evident that achieving optimal outcomes in mothers with diabetes is clearly impacted by ideal glycemic control but goes far beyond it. The intrauterine metabolic environment seems to have long-term implications on the future health of the offspring so that the effectiveness of our current approaches can no longer be simply measured by whether or not maternal glucose values are at goal.

Prediction of gestational diabetes mellitus in the first trimester, comparison of fasting plasma glucose, two-step and one-step methods: a prospective randomized controlled trial

Our aim was to evaluate and compare the diagnostic performance of three methods commonly used for GDM screening: fasting plasma glucose (FPG), two-step 50 g glucose challenge test (GCT), and 75 g glucose tolerance test (GTT) in a randomized study design to predict GDM in the first trimester and determine the best approach in predicting GDM. In a non-blind, parallel-group prospective randomized controlled study; 736 singleton pregnant women underwent FPG testing in the first trimester and randomly assigned to two groups; two-step 50 g GCT and 75 g GTT. GDM diagnosis was made according to Carpenter-Coustan or ADA (American Diabetes Association) criteria in two-step 50 g GCT and 75 g GTT groups, respectively. Subsequent testing was performed by two-step 50 g GCT at 24-28 weeks for screen negatives. After excluding the women who were lost to follow-up or withdrawn as a result of pregnancy loss, 486 pregnant women were recruited in the study. The FPG, two-step GCT, and one-step GTT methods identified GDM in 25/486 (5.1 %), 15/248 (6.0 %), and 27/238 (11.3 %) women, respectively. Area under ROC curves were 0.623, 0.708, and 0.792, respectively. Sensitivities were 47.17, 68.18, and 87.1 %, respectively. Specificities were 77.37, 100, and 100 %, respectively. Positive predictive values were 20.33, 100, and 100 %, respectively. Negative predictive values were 92.29, 97, and 98.1 %, respectively. Until superior screening alternatives become available, the 75 g GTT may be preferred for GDM screening in the first trimester.

Shape information in repeated glucose curves during pregnancy provided significant physiological information for neonatal outcomes

Objective

To use multilevel functional principal component analysis to exploit the information inherent in the shape of longitudinally sampled glucose curves during pregnancy, and to analyse the impact of glucose curve characteristics on neonatal birth weight, percentage fat and cord blood C-peptide.

Study Design and Setting

A cohort study of healthy, pregnant women (n = 884). They underwent two oral glucose tolerance tests (gestational weeks 14–16 and 30–32), which gave two glucose curves per woman.

Results

Glucose values were higher, and peaked later in third trimester than in early pregnancy. The curve characteristic “general glucose level” accounted for 91% of the variation across visits, and 72% within visits. The curve characteristics “timing of postprandial peak”, and “oscillating glucose levels” accounted for a larger part of the variation within visits (15% and 8%), than across visits (7% and <2%). A late postprandial peak during pregnancy, and high general glucose levels in third trimester had significant, positive effects on birth weight (p<0.05). Generally high glucose levels during pregnancy had a significant, positive impact on neonatal percentage fat (p = 0.04). High general glucose level in third trimester had a significant, positive impact on cord blood C-peptide (p = 0.004).

Conclusion

Shape information in entire OGTT curves provides significant physiological information of importance for several outcomes, and may contribute to the understanding of the metabolic changes during pregnancy.

A standard approach to continuous glucose monitor data in pregnancy for the study of fetal growth and infant outcomes

The power of continuous glucose monitoring system (CGMS) technology to profile glycemic patterns throughout a 24-h period has benefited the care of individuals with diabetes mellitus for over 10 years. Recently, this technology has been utilized to better understand glucose patterns in pregnancy, especially as they relate to abnormal fetal growth given that adiposity at birth is associated with increased risks for childhood obesity and metabolic syndrome. However, the lack of a standardized approach to defining glucose measures associated with maternal outcomes and fetal growth has greatly limited comparison and pooling of CGMS data among pregnancy trials, hindering our ability to take advantage of the enormous amount of data available to explore these relationships. The purpose of this article is to offer a methodical approach to the identification and extraction of CGMS-derived glucose variables for the characterization of glycemic profiles in pregnant women, particularly focusing on women with gestational diabetes or obesity who are at risk for abnormal fetal growth. A review of the properties of CGMS data and examples of how CGMS data in pregnancy have been reported to date are included. We further define several pregnancy-relevant, CGMS-derived glucose variables and directly apply them to unpublished data to illustrate how these measures might be utilized. This approach offers one possible standardized method to define and analyze these time-sensitive glucose measures to facilitate comparisons among studies and to increase our understanding of how glycemic profiles contribute to excess infant adiposity in pregnant women with and without diabetes.

Role of continuous glucose monitoring in the management of diabetic pregnancy

Self-monitoring of blood glucose (SMBG) with intermittent capillary glucose fingerstick tests is currently the universally accepted method of glucose monitoring in pregnancy. During pregnancy SMBG tests are recommended before and after meals and before bed (typically 7 values/d). Continuous glucose monitoring systems consist of a disposable subcutaneous glucose-sensing device, electrochemically measuring glucose levels in subcutaneous tissues every 10 seconds, providing an average interstitial glucose value every 5 minutes (typically 288 values/d). From a research perspective this provides unprecedented insights into the pathophysiology of glucose metabolism, while from a clinical perspective it can facilitate enhanced patient-professional decision making, patient motivation, and improved glycaemic control. CGM has thus been described as a "roadmap for effective self-management" and as a "stepping stone in the journey towards a cure." This review will consider the lessons learned and evidence supporting current and potential future use of CGM in the management of diabetes in pregnancy.

Shape information from glucose curves: functional data analysis compared with traditional summary measures

Background

Plasma glucose levels are important measures in medical care and research, and are often obtained from oral glucose tolerance tests (OGTT) with repeated measurements over 2–3 hours. It is common practice to use simple summary measures of OGTT curves. However, different OGTT curves can yield similar summary measures, and information of physiological or clinical interest may be lost. Our mean aim was to extract information inherent in the shape of OGTT glucose curves, compare it with the information from simple summary measures, and explore the clinical usefulness of such information.

Methods

OGTTs with five glucose measurements over two hours were recorded for 974 healthy pregnant women in their first trimester. For each woman, the five measurements were transformed into smooth OGTT glucose curves by functional data analysis (FDA), a collection of statistical methods developed specifically to analyse curve data. The essential modes of temporal variation between OGTT glucose curves were extracted by functional principal component analysis. The resultant functional principal component (FPC) scores were compared with commonly used simple summary measures: fasting and two-hour (2-h) values, area under the curve (AUC) and simple shape index (2-h minus 90-min values, or 90-min minus 60-min values). Clinical usefulness of FDA was explored by regression analyses of glucose tolerance later in pregnancy.

Results

Over 99% of the variation between individually fitted curves was expressed in the first three FPCs, interpreted physiologically as “general level” (FPC1), “time to peak” (FPC2) and “oscillations” (FPC3). FPC1 scores correlated strongly with AUC (r=0.999), but less with the other simple summary measures (−0.42≤r≤0.79). FPC2 scores gave shape information not captured by simple summary measures (−0.12≤r≤0.40). FPC2 scores, but not FPC1 nor the simple summary measures, discriminated between women who did and did not develop gestational diabetes later in pregnancy.

Conclusions

FDA of OGTT glucose curves in early pregnancy extracted shape information that was not identified by commonly used simple summary measures. This information discriminated between women with and without gestational diabetes later in pregnancy.

Comparison of Insulin Lispro Protamine Suspension with NPH Insulin in Pregnant Women with Type 2 and Gestational Diabetes Mellitus: Maternal and Perinatal Outcomes

Insulin therapy is still the gold standard in diabetic pregnancy. Insulin lispro protamine suspension is an available basal insulin analogue. Aim. To study pregnancy outcomes of women with type 2 and gestational diabetes mellitus when insulin lispro protamine suspension or human NPH insulin was added to medical nutrition therapy and/or short-acting insulin. Methods. In this retrospective study, for maternal outcome we recorded time and mode of delivery, hypertension, glycaemic control (fasting blood glucose and HbA1c), hypoglycemias, weight increase, and insulin need. For neonatal outcome birth weight and weight class, congenital malformations was recorded and main neonatal complications. Two-tail Student's t-test and chi-square test were performed when applicable; significant P < 0.05. Results. Eighty-nine pregnant women (25 with type 2 diabetes and 64 with gestational diabetes mellitus; 53 under insulin lispro protamine suspension and 36 under human NPH insulin) were recruited. Maternal and neonatal outcomes were quite similar between the two therapeutic approaches; however, insulin need was higher in NPH. At the end of pregnancy, eight women with gestational diabetes continued to use only basal insulin analogue. Conclusions. Pregnancy outcome in type 2 and gestational diabetes mellitus with insulin lispro protamine suspension was similar to that with NPH insulin, except for a lower insulin requirement.

A two-step screening algorithm including fasting plasma glucose measurement and a risk estimation model is an accurate strategy for detecting gestational diabetes mellitus

AIMS/HYPOTHESIS

It is currently not clear how to construct a time- and cost-effective screening strategy for gestational diabetes mellitus (GDM). Thus, we elaborated a simple screening algorithm combining (1) fasting plasma glucose (FPG) measurement; and (2) a multivariable risk estimation model focused on individuals with normal FPG levels to decide if a further OGTT is indicated.

METHODS

A total of 1,336 women were prospectively screened for several risk factors for GDM within a multicentre study conducted in Austria. Of 714 women (53.4%) who developed GDM using recent diagnostic guidelines, 461 were sufficiently screened with FPG. A risk prediction score was finally developed using data from the remaining 253 women with GDM and 622 healthy women. The screening algorithm was validated with a further 258 pregnant women.

RESULTS

A risk estimation model including history of GDM, glycosuria, family history of diabetes, age, preconception dyslipidaemia and ethnic origin, in addition to FPG, was accurate for detecting GDM in participants with normal FPG. Including an FPG pretest, the receiver operating characteristic AUC of the screening algorithm was 0.90 (95% CI 0.88, 0.91). A cut-off value of 0.20 was able to differentiate between low and intermediate risk for GDM with a high sensitivity. Comparable results were seen with the validation cohort. Moreover, we demonstrated an independent association between values derived from the risk estimation and macrosomia in offspring (OR 3.03, 95% CI 1.79, 5.19, p < 0.001).

CONCLUSIONS/INTERPRETATION

This study demonstrates a new concept for accurate but cheap GDM screening. This approach should be further evaluated in different populations to ensure an optimised diagnostic algorithm.

Continuous glucose monitoring in pregnancy: new frontiers in clinical applications and research

Current treatment of diabetes in pregnancy relies on intermittent self-monitoring of blood glucoses using finger sticks to monitor capillary blood glucoses. Continuous glucose monitoring (CGM) systems are an emerging technology that allow frequent glucose measurements (every 5 min) and the ability to monitor glucose trends in real time. Although these devices are currently expensive and mildly invasive to use, there is huge potential for their use in both the research and clinical realms. From a research perspective, there is the potential to better understand glucose metabolism in pregnancy, both in patients with and without diabetes. For the treating clinician, CGM has the potential to improve detection of hyperglycemic excursions as well as asymptomatic hypoglycemia and the data to improve management of glucose levels in diabetes patients. In this article, we review current literature examining use of CGM in both research and clinical applications.

Continuous glucose monitoring during breastfeeding in women with recent gestational diabetes mellitus

AIMS

This study monitored blood glucose profiles in normotolerant breastfeeding women, with and without previous gestational diabetes, in real life in order to identify normal blood glucose fluctuations during breastfeeding.

SUBJECTS AND METHODS

Two groups were studied: (1) 18 women with recent gestational diabetes mellitus but normotolerant postpartum (pGDM-N group) and (2) 15 women normotolerant both during pregnancy and postpartum (pN-N group). All participants underwent continuous glucose monitoring during which they recorded their main daily activities and three standardized events: "suckling," "meal," and "meal and suckling." Other than these three events, these women were essentially on an "ad lib" diet. Data were expressed as median and SD values. Student's t test and Fisher's test were used to compare mean, variances, and percentages. Differences were significant with P<0.05. Clustering analysis was used to determine the normal range of glucose values.

RESULTS

The two groups were matched for age, follow-up duration, and monitoring measurements but not for body mass index. Blood glucose levels and variances were higher in the pGDM-N group, particularly during daytime and the three standardized events, and were not related to body mass index. Suckling had no direct effect on glucose profile during both the non-fed and the fed state. Blood glucose levels that best represent the normal breastfeeding population were between 50 and 126 mg/dL (from 2.8 to 7.0 mmol/L).

CONCLUSIONS

Three months after delivery, normotolerant women with recent gestational diabetes had higher daily blood glucose levels than women who were always normotolerant, with no direct effect of suckling. The blood glucose profiles of healthy subjects could be representative of the normal range of the population during breastfeeding.

Chronic pulsatile hyperglycemia reduces insulin secretion and increases accumulation of reactive oxygen species in fetal sheep islets

Children from diabetic pregnancies have a greater incidence of type 2 diabetes. Our objective was to determine if exposure to mild-moderate hyperglycemia, by modeling managed diabetic pregnancies, affects fetal β-cell function. In sheep fetuses, β-cell responsiveness was examined after 2 weeks of sustained hyperglycemia with 3 pulses/day, mimicking postprandial excursions, and compared to saline-infused controls (n = 10). Two pulsatile hyperglycemia (PHG) treatments were studied: mild (mPHG, n = 5) with +15% sustained and +55% pulse; and moderate (PHG, n = 10) with +20% sustained and +100% pulse. Fetal glucose-stimulated insulin secretion and glucose-potentiated arginine insulin secretion were lower (P < 0.05) in PHG (0.86 ± 0.13 and 2.91 ± 0.39  ng/ml plasma insulin) but not in mPHG fetuses (1.21 ± 0.08 and 4.25 ± 0.56  ng/ml) compared to controls (1.58 ± 0.25 and 4.51 ± 0.56  ng/ml). Islet insulin content was 35% lower in PHG and 35% higher in mPHG vs controls (P < 0.01). Insulin secretion and maximally stimulated insulin release were also reduced (P < 0.05) in PHG islets due to lower islet insulin content. Isolated PHG islets also had 63% greater (P < 0.01) reactive oxygen species (ROS) accumulation at 11.1  mmol/l glucose than controls (P < 0.01), but oxidative damage was not detected in islet proteins. PHG fetuses showed evidence of oxidative damage to skeletal muscle proteins (P < 0.05) but not insulin resistance. Our findings show that PHG induced dysregulation of islet ROS handling and decreased islet insulin content, but these outcomes are independent. The β-cell outcomes were dependent on the severity of hyperglycemia because mPHG fetuses had no distinguishable impairments in ROS handling or insulin secretion but greater insulin content.

Gestational diabetes mellitus: Non-insulin management

Gestational diabetes mellitus (GDM) complicates a substantial number of pregnancies. There is consensus that in patients of GDM, excellent blood glucose control, with diet and, when necessary, oral hypoglycemics and insulin results in improved perinatal outcomes, and appreciably reduces the probability of serious neonatal morbidity compared with routine prenatal care. Goals of metabolic management of a pregnancy complicated with GDM have to balance the needs of a healthy pregnancy with the requirements to control glucose level. Medical nutrition therapy is the cornerstone of therapy for women with GDM. Surveillance with daily self-monitoring of blood glucose has been found to help guide management in a much better way than blood glucose checking in labs and clinics, which tends to be less frequent. Historically, insulin has been the therapeutic agent of choice for controlling hyperglycemia in pregnant women. However, difficulty in medication administration with multiple daily injections, potential for hypoglycemia, and increase in appetite and weight make this therapeutic option cumbersome for many pregnant patients. Use of oral hypogycemic agents (OHAs) in pregnancy has opened new vistas for GDM management. At present, there is a growing acceptance of glyburide (glibenclamide) use as the primary therapy for GDM. Glyburide and metformin have been found to be safe, effective and economical for the treatment of gestational diabetes. Insulin, however, still has an important role to play in GDM. GDM is a window of opportunity, which needs to be seized, for prevention of diabetes in future life. Goal of our educational programs should be not only to improve pregnancy outcomes but also to promote healthy lifestyle changes for the mother that will last long after delivery. Team effort on part of obstetricians and endocrinologists is required to make "the diabetes capital of the world" into "the diabetes care capital of the world".

Continuous glucose profiles in obese and normal-weight pregnant women on a controlled diet: metabolic determinants of fetal growth

OBJECTIVE

We sought to define 24-h glycemia in normal-weight and obese pregnant women using continuous glucose monitoring (CGM) while they consumed a habitual and controlled diet both early and late in pregnancy.

RESEARCH DESIGN AND METHODS

Glycemia was prospectively measured in early (15.7 ± 2.0 weeks' gestation) and late (27.7 ± 1.7 weeks' gestation) pregnancy in normal-weight (n = 22) and obese (n = 16) pregnant women on an ad libitum and controlled diet. Fasting glucose, triglycerides (early pregnancy only), nonesterified fatty acids (FFAs), and insulin also were measured.

RESULTS

The 24-h glucose area under the curve was higher in obese women than in normal-weight women both early and late in pregnancy despite controlled diets. Nearly all fasting and postprandial glycemic parameters were higher in the obese women later in pregnancy, as were fasting insulin, triglycerides, and FFAs. Infants born to obese mothers had greater adiposity. Maternal BMI (r = 0.54, P = 0.01), late average daytime glucose (r = 0.48, P < 0.05), and late fasting insulin (r = 0.49, P < 0.05) correlated with infant percentage body fat. However, early fasting triglycerides (r = 0.67, P < 0.001) and late fasting FFAs (r = 0.54, P < 0.01) were even stronger correlates.

CONCLUSIONS

This is the first study to demonstrate that obese women without diabetes have higher daytime and nocturnal glucose profiles than normal-weight women despite a controlled diet both early and late in gestation. Body fat in infants, not birth weight, was related to maternal BMI, glucose, insulin, and FFAs, but triglycerides were the strongest predictor. These metabolic findings may explain higher rates of infant macrosomia in obese women, which might be targeted in trials to prevent excess fetal growth.

Methods for the screening and diagnosis of gestational diabetes mellitus between 24 and 28 weeks of pregnancy

The aim of this review is to provide answers to the question “How does one screen for and diagnose gestational diabetes mellitus (GDM) between 24 and 28 weeks gestation?” Two methods are currently widely used: a one-step approach (the 75g-Oral Glucose Tolerance Test, OGTT) and a two-step approach (the 50g Glucose Challenge Test, GCT, followed by 100g-OGTT). A review of the literature showed that both methods had good reproducibility (around 80%), whilst neither required preliminary diet changes. The data of the Hyperglycaemia Adverse Pregnancy Outcomes (HAPO) study on materno-foetal morbidity provided consistent support in favour of the 75g-OGTT. In addition, this one-step method presents several advantages over the two-step method, i.e. it provides a faster diagnosis time, better tolerance and it is easier to remember. We thus recommend a 75g-OGTT including three measures of the glycaemia at times 0, 1 and 2 hours for the diagnosis of GDM between 24-28 weeks of pregnancy. A discussion of alternative methods revealed that measuring Fasting Glycaemia (FG) between 24 and 28 weeks of pregnancy was unsuitable, and that measuring HbA1c, fructosamine, glycosuria, or random and postprandial plasma glucose was not advisable. This is based on the fact that too few studies have evaluated these methods, and that the studies usually involved heterogeneous populations in varying numbers, using differing criteria and sensitivity values. However, HbA1c measurements may prove useful in detecting pre-pregnancy diabetes mellitus.

Criteria for screening and diagnosis of gestational diabetes mellitus in the first trimester of pregnancy

OBJECTIVE

To propose new cutoffs in plasma glucose levels in screening and diagnosis of gestational diabetes mellitus (GDM) in the first trimester of pregnancy.

METHODS

A 50-gram oral glucose challenge test (GCT) was performed in 1,716 singleton pregnancies at 6-14 weeks' gestation. In those with a positive GCT, a 100-gram glucose tolerance test (GTT) was carried out. The GCT and as necessary the GTT were repeated at 20-30 weeks. The relation of the results of the GCT and GTT at 6-14 weeks to that at 20-30 weeks was examined.

RESULTS

The diagnosis of GDM was made in 85 cases. In the GCT, there was a significant association between 1-hour plasma glucose levels at 6-14 weeks and at 20-30 weeks (r = 0.558, p < 0.0001), and in all cases of GDM, the level was 130 mg/dl or more at 6-14 weeks and 140 mg/dl or more at 20-30 weeks. In the GTT, the plasma glucose 1, 2 and 3 h after the 100-gram glucose load at 6-14 weeks was, respectively, 18, 29 and 35% lower than at 20-30 weeks.

CONCLUSION

Effective diagnosis of GDM in the first trimester can be achieved by lowering the GCT and GTT plasma glucose cutoffs.

Normal fasting plasma glucose levels during pregnancy: a hospital-based study

OBJECTIVE

Recently, the International Association of Diabetes and Pregnancy Study Groups have suggested new criteria for the diagnosis of gestational diabetes including a fasting glucose level of ≥92 mg/dL. We determined reference levels for normal fasting plasma glucose levels throughout pregnancy and evaluated the new normal cut-off for fasting glucose level.

METHODS

Charts of patients who delivered in our hospital between June 2001 and June 2006 were reviewed. Women with pregestational diabetes, fasting glucose level >105 mg/dL or delivery at <24 weeks were excluded. Fasting glucose levels were assessed in 11 time categories between three months prior and four months postpartum in 7946 women.

RESULTS

Compared to preconception levels, fasting glucose levels decreased by a median of 3 mg/dL in the first trimester (81-78 mg/dL). During the third trimester a slight further glucose reduction was observed (median 76 mg/dL). After delivery fasting glucose levels increased sharply (84 mg/dL in the puerperium and 81 mg/dL by three months postpartum). Throughout pregnancy 5.2-9.0% of pregnant women had a fasting glucose level of ≥92 mg/dL [compared to 8.2% in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study].

CONCLUSION

Fasting glucose levels decrease early in pregnancy with only slight further decrease later on. It seems that the same fasting glucose cut-off can be used throughout pregnancy for the diagnosis of gestational diabetes mellitus.

[Methods of screening of gestational diabetes between 24 and 28 weeks' gestation]

The aim of this review is to answer the question "how to detect the gestational diabetes mellitus (GDM) between 24 and 28 weeks of gestation?". Two approaches are well established: one-step approach (75 g-OGTT) and two-steps approach (50 g followed 100g-OGTT). The analysis of the literature shows that each of these methods has a good reproducibility close to 80 %, without requiring preliminary dietetics. The HAPO study provides consistent data about the 75 g-OGTT materno-fetal morbidity related. Furthermore, the one-step approach, relationship two-steps approach, has several advantages: reduction of time of diagnosis and primary care, better tolerance, simpler memorization. We recommend for the screening and the diagnosis of GDM an 75 g-OGTT with three measures: FPG, 1-h and 2-h. The various alternative methods are discussed. The measure of the fasting blood glucose isolated between 24 and 28 weeks of gestation is not a relevant approach. None of the other alternative methods (HbA1c, fructosamine, glycosuria, random and postprandial plasma glucose) cannot be recommended. Indeed, these methods have been addressed in little numerous studies, among heterogeneous populations, using variable criteria, and variable sensitivity values. Only the HbA1c might be useful to detect a pre-pregnancy diabetes mellitus.

First trimester fasting hyperglycemia as a predictor for the development of gestational diabetes mellitus

OBJECTIVE

Screening for gestational diabetes mellitus (GDM) is usually done at 24-28 weeks of gestation. Our goal was to study the association between first trimester fasting plasma glucose level and GDM risk and to evaluate its efficacy as a screening test for GDM in comparison to a traditional risk factor, pregestational body mass index (BMI).

STUDY DESIGN

The charts of all patients who delivered in our hospital between June 2001 and June 2006 were reviewed. Only subjects with a singleton pregnancy and a recorded first trimester fasting glucose level and BMI were studied. Women with pregestational diabetes mellitus, fasting glucose level >105mg/dl or delivery at <24 weeks were excluded. Screening properties of both fasting glucose level and BMI were calculated and compared using receiver operator characteristic curves.

RESULTS

GDM was diagnosed in 135 of the 4876 women included in this study. Fasting glucose cut-off levels of 80-85mg/dl yielded sensitivities of 75-55% and specificities of 52-75% for GDM prediction. BMI cut-off values of 25-28 had sensitivities of 60-40% and specificities of 72-86% for GDM prediction. Receiver operator curves for fasting glucose levels and BMI showed similar performance in predicting GDM (area under curve 0.72±0.023 vs. 0.74±0.021 (P=0.44)). There was approximately a 1.5-fold increase in the risk of developing GDM with each 5mg/dl increase in fasting glucose or 3.5kg/m² increase in BMI.

CONCLUSION

Higher first trimester fasting glucose levels, within the normoglycemic range, constitute an independent risk factor for the development of GDM among young pregnant women.

Increased risk of macrosomia among overweight women with high gestational rise in fasting glucose

OBJECTIVES

Maternal overweight is a risk factor for gestational diabetes (GDM) and for newborn macrosomia. Among women without GDM, it is not well understood why some women with high body mass index (BMI) give birth to macrosomic newborns while others do not. We wanted to explore the effect of BMI and fasting plasma glucose (FPG), fasting plasma insulin (FPI) and insulin resistance (HOMA-IR) on the risk of newborn macrosomia.

METHODS

A cohort of 553 Caucasian women was followed throughout pregnancy. The dependent variable was high birth weight (>or=4200 g). Independent variables included gestational age, intake of macronutrients and energy, maternal BMI, weight gain, FPG, FPI and HOMA-IR.

RESULTS

FPG in late pregnancy (30-32 weeks) remained a significant determinant of newborn macrosomia in multiple regression analysis (OR: 1.9, 95% CI: [1.1, 3.4]), whereas FPI and HOMA-IR did not. The women in the highest BMI quartile (>or=27 kg/m(2)) who gave birth to macrosomic newborns had higher increase in FPG and HOMA-IR from early to late pregnancy. Among women in this BMI category, the risk for delivering a macrosomic infant was higher among those with an increase in FPG above 0.60 mmol/l (upper quartile) (OR = 4.5, 95% CI: [1.7, 12.5]).

CONCLUSION

Fasting plasma glucose at week 30-32, but not fasting plasma insulin or insulin resistance, is a determinant of newborn macrosomia. Overweight women with high increase in fasting plasma glucose from early to late pregnancy had a 4.5-fold increase in risk of newborn macrosomia compared to the remaining group with high BMI.

First-trimester fasting hyperglycemia and adverse pregnancy outcomes

OBJECTIVE

The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study found strong associations between higher levels of maternal glucose at 24-32 weeks, within what is currently considered normoglycemia and adverse pregnancy outcomes. Our aim was to evaluate the associations between first-trimester fasting plasma glucose level and adverse pregnancy outcomes.

RESEARCH DESIGN AND METHODS

Charts of all patients who delivered at our hospital between June 2001 and June 2006 were reviewed. Only subjects with singleton pregnancy and a recorded first-trimester fasting glucose level were included. Women with pregestational diabetes, fasting glucose level >105 mg/dl, or delivery <24 weeks were excluded. Fasting glucose levels were analyzed in seven categories, similar to the HAPO study. The main outcomes were development of gestational diabetes mellitus (GDM), large-for-gestational-age (LGA) neonates and/or macrosomia, and primary cesarean section. Multivariate logistic regression analysis was used; significance was <0.05.

RESULTS

A total of 6,129 women had a fasting glucose test at median of 9.5 weeks. There were strong, graded associations between fasting glucose level and primary outcomes. The frequency of GDM development increased from 1.0% in the lowest glucose category to 11.7% in the highest (adjusted odds ratio 11.92 [95% CI 5.39-26.37]). The frequency of LGA neonates and/or macrosomia increased from 7.9 to 19.4% (2.82 [1.67-4.76]). Primary cesarean section rate increased from 12.7 to 20.0% (1.94 [1.11-3.41]).

CONCLUSIONS

Higher first-trimester fasting glucose levels, within what is currently considered a nondiabetic range, increase the risk of adverse pregnancy outcomes. Early detection and treatment of women at high risk for these complications might improve pregnancy outcome.

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.