The number of abnormal plasma glucose values in the oral glucose tolerance test and the feto-maternal outcome of pregnancy

Fetal abdominal obesity in women with one value abnormality on diagnostic test for gestational diabetes mellitus

Previous studies have shown that fetal abdominal obesity (FAO) was already observed at the time of gestational diabetes mellitus (GDM) diagnosis and persisted until delivery despite management in older and/or obese women. In this study, we investigated whether fetuses of women with milder hyperglycemia than GDM have accelerated abdominal growth, leading to adverse pregnancy outcomes. We retrospectively reviewed the medical records of 7,569 singleton pregnant women who were universally screened using a 50-g glucose challenge test (GCT) and underwent a 3-h 100-g oral glucose tolerance test (OGTT) if GCT result was ≥140mg/dL. GDM, one value abnormality (OVA), and normal glucose tolerance (NGT, NGT1: GCT negative, NGT2: GCT positive & OGTT negative) were diagnosed using Carpenter-Coustan criteria. With fetal biometry data measured simultaneously with 50-g GCT, relative fetal abdominal overgrowth was investigated by assessing the fetal abdominal overgrowth ratios (FAORs) of the ultrasonographically estimated gestational age (GA) of abdominal circumference(AC) per actual GA by the last menstruation period(LMP), biparietal diameter(BPD) or femur length(FL), respectively. FAO was defined as FAOR ≥90th percentile The FAORs of GA-AC/GA-LMP and GA-AC/GA-BPD were significantly higher in OVA subjects compared to NGT subjects but not in NGT2 subjects. Although the frequency of FAO in OVA (12.1%) was between that of NGT (9.6%) and GDM (18.3%) without statistically significant difference, the prevalence of large for gestational age at birth and primary cesarean delivery rates were significantly higher in OVA (9.8% and 29.7%) than in NGT (5.1% and 21.5%, p<0.05). Particularly, among OVA subjects with FAO, the prevalence (33.3% and 66.7%) was significantly higher than in those without FAO (9.7% and 24.2%, p<0.05). The degree of fetal abdominal growth acceleration in OVA subjects was intermediate between that of NGT and GDM subjects. OVA subjects with FAO at the time of GDM diagnosis were strongly associated with adverse pregnancy outcomes.

Prevalence of maternal hyperglycemic subtypes by race/ethnicity and associations between these subtypes with adverse pregnancy outcomes: Findings from a large retrospective multi-ethnic cohort in the United States

AIMS

With the two-step gestational diabetes mellitus (GDM) screening approach, hyperglycemic subtypes can be identified. We aimed to investigate racial/ethnic differences in the prevalence of hyperglycemic subtypes and to examine the associations between these subtypes and adverse pregnancy outcomes.

METHODS

In this retrospective cohort, 11,405 pregnancies were screened using the two-step approach. Hyperglycemic subtypes included: pregnancy-impaired glucose intolerance-I (PIGT-I), PIGT-II, GDM-I (abnormal post-load glucose only), and GDM-II (abnormal fasting & post-load glucose). Modified Poisson regressions with robust error variance were used to estimate age-adjusted prevalence ratios (PR) of hyperglycemic subtypes and multivariable-adjusted risk ratios (RR) of adverse pregnancy outcomes.

RESULTS

The prevalence of hyperglycemic subtypes was higher in Asians (PIGT-I: 1.51 [95% confidence interval 1.35-1.69]; PIGT-II: 2.18 [1.78-2.68]; GDM-I: 2.55 [2.10-3.10]; GDM-II: 1.55 [1.08-2.21]) and Hispanics (PIGT-I: 1.32 [1.16-1.50]; PIGT-II: 2.07 [1.67-2.57]; GDM-I: 1.69 [1.35-2.13]; GDM-II: 2.68 [1.93-3.71]) than non-Hispanic Whites (NHW). Despite low GDM prevalence, Japanese and Koreans had higher PIGT prevalence than NHW. PIGT-II was positively associated with hypertensive disorders of pregnancy (1.19 [1.02-1.38]), large-for-gestational age (1.73 [1.37-2.18]), and preterm birth (PB, 1.33 [1.05-1.68]). PIGT-I (1.23 [1.04-1.45]) and GDM-I (1.56 [0.87-1.71]) were positively related to PB.

CONCLUSIONS

The prevalence of hyperglycemic subtypes varies by race/ethnicity and they have distinct health implications.

Mid-Trimester Fetal Anterior Abdominal Wall Subcutaneous Tissue Thickness: An Early Ultrasonographic Predictor of Gestational Diabetes Mellitus

Background This study aimed to determine whether mid-trimester fetal anterior abdominal wall subcutaneous tissue thickness (FASTT) is an early sonographic predictor of gestational diabetes mellitus (GDM), as well as to study its correlation with maternal glycemic values on GDM screening at 24-28 weeks. Methodology We conducted a prospective, case-control study. FASTT was assessed at anomaly scan in 896 uncomplicated singleton pregnancies. The 75-gram oral glucose tolerance test (OGTT) was done for all included patients at 24-28 weeks. Women diagnosed with GDM were taken as cases and appropriately matched in equal numbers as controls. Statistical analysis was done using SPSS version 20 (IBM Corp., Armonk, NY, USA). Independent-samples t-test, chi-square test, receiver operating characteristic curve, and Pearson's correlation coefficient (r) were performed wherever applicable. Results A total of 93 cases and 94 controls were included. Fetuses of women with GDM had significantly higher mean FASTT at 20 weeks (1.605 ± 0.328 mm vs. 1.222 ± 0.121 mm; p < 0.001). The FASTT cut-off obtained was 1.35 mm (sensitivity = 79.6%, specificity = 87.2%, positive predictive value = 86%, negative predictive value = 81.2%). There was a moderate positive correlation between fasting blood sugar (FBS) and two-hour OGTT values and FASTT (r = 0.332, p < 0.001 and r = 0.399, p < 0.001, respectively). FASTT >1.35 mm had an independent predictive value for GDM and was associated with a 19.608-fold increased risk of GDM. Conclusions FASTT values greater than 1.35 mm at 20 weeks are associated with a significantly increased risk of GDM. In addition, FASTT correlates with FBS and two-hour OGTT at 24-28 weeks and is a simple predictor of GDM at 18-20 weeks.

Gestational diabetes mellitus and adverse pregnancy outcomes: systematic review and meta-analysis

OBJECTIVE

To investigate the association between gestational diabetes mellitus and adverse outcomes of pregnancy after adjustment for at least minimal confounding factors.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Web of Science, PubMed, Medline, and Cochrane Database of Systematic Reviews, from 1 January 1990 to 1 November 2021.

REVIEW METHODS

Cohort studies and control arms of trials reporting complications of pregnancy in women with gestational diabetes mellitus were eligible for inclusion. Based on the use of insulin, studies were divided into three subgroups: no insulin use (patients never used insulin during the course of the disease), insulin use (different proportions of patients were treated with insulin), and insulin use not reported. Subgroup analyses were performed based on the status of the country (developed or developing), quality of the study, diagnostic criteria, and screening method. Meta-regression models were applied based on the proportion of patients who had received insulin.

RESULTS

156 studies with 7 506 061 pregnancies were included, and 50 (32.1%) showed a low or medium risk of bias. In studies with no insulin use, when adjusted for confounders, women with gestational diabetes mellitus had increased odds of caesarean section (odds ratio 1.16, 95% confidence interval 1.03 to 1.32), preterm delivery (1.51, 1.26 to 1.80), low one minute Apgar score (1.43, 1.01 to 2.03), macrosomia (1.70, 1.23 to 2.36), and infant born large for gestational age (1.57, 1.25 to 1.97). In studies with insulin use, when adjusted for confounders, the odds of having an infant large for gestational age (odds ratio 1.61, 1.09 to 2.37), or with respiratory distress syndrome (1.57, 1.19 to 2.08) or neonatal jaundice (1.28, 1.02 to 1.62), or requiring admission to the neonatal intensive care unit (2.29, 1.59 to 3.31), were higher in women with gestational diabetes mellitus than in those without diabetes. No clear evidence was found for differences in the odds of instrumental delivery, shoulder dystocia, postpartum haemorrhage, stillbirth, neonatal death, low five minute Apgar score, low birth weight, and small for gestational age between women with and without gestational diabetes mellitus after adjusting for confounders. Country status, adjustment for body mass index, and screening methods significantly contributed to heterogeneity between studies for several adverse outcomes of pregnancy.

CONCLUSIONS

When adjusted for confounders, gestational diabetes mellitus was significantly associated with pregnancy complications. The findings contribute to a more comprehensive understanding of the adverse outcomes of pregnancy related to gestational diabetes mellitus. Future primary studies should routinely consider adjusting for a more complete set of prognostic factors.

REVIEW REGISTRATION

PROSPERO CRD42021265837.

Perinatal Outcomes in Obese Women with One Abnormal Value on 3-Hour Oral Glucose Tolerance Test

OBJECTIVE

This study aimed to determine if one abnormal value of four on the diagnostic 3-hour oral glucose tolerance test (OGTT) is associated with adverse perinatal outcomes in obese women.

STUDY DESIGN

This is a secondary analysis of a prospective study of nulliparous women in eight geographic regions. Women with body mass index <30 kg/m² and pregestational diabetes mellitus (GDM) were excluded. Four groups were compared: (1) normal 50-g 1-hour glucose screen, (2) elevated 1-hour glucose screen with normal 100-g 3-hour diagnostic OGTT, (3) elevated 1-hour glucose screen and one of four abnormal values on 3-hour OGTT, and (4) GDM. Using multivariable logistic regression adjusting for covariates, the women in the groups with dysglycemia were compared with those in the normal screen group for maternal and neonatal outcomes.

RESULTS

Among 1,713 obese women, 1,418 (82.8%) had a normal 1-hour glucose screen, 125 (7.3%) had a normal 3-hour diagnostic OGTT, 72 (4.2%) had one abnormal value on their diagnostic OGTT, and 98 (5.7%) were diagnosed with GDM. The one abnormal value group had increased risk of large for gestational age (LGA) neonates (adjusted odds ratio [aOR] = 2.24, 95% confidence interval [CI]: 1.31-3.82), cesarean delivery (aOR = 2.19, 95% CI: 1.34-3.58), and hypertensive disorders of pregnancy (aOR = 2.19, 95% CI: 1.32-3.63) compared with normal screens. The one abnormal value group also had an increased risk of preterm birth <37 weeks (aOR = 2.63, 95% CI: 1.43-4.84), neonatal respiratory support (aOR = 2.38, 95% CI: 1.23-4.60), and neonatal hyperbilirubinemia (aOR = 2.00, 95% CI: 1.08-3.71). There was no association between one abnormal value with shoulder dystocia and neonatal hypoglycemia.

CONCLUSION

For obese women, one abnormal value on the 3-hour OGTT confers increased perinatal adverse outcomes. These women should be studied further to determine if nutrition counseling and closer fetal monitoring improve outcomes even in the absence of a diagnosis of GDM.

KEY POINTS

· Study of obese women with one abnormal value on OGTT.. · Adverse maternal and neonatal outcomes were found, including more LGA neonates.. · Neonates were not at increased risk of hypoglycemia..

How Can We Adopt the Glucose Tolerance Test to Facilitate Predicting Pregnancy Outcome in Gestational Diabetes Mellitus?

BACKGROUND

We investigated how 100-g oral glucose tolerance test (OGTT) results can be used to predict adverse pregnancy outcomes in gestational diabetes mellitus (GDM) patients.

METHODS

We analyzed 1,059 pregnant women who completed the 100-g OGTT between 24 and 28 weeks of gestation. We compared the risk of adverse pregnancy outcomes according to OGTT patterns by latent profile analysis (LPA), numbers to meet the OGTT criteria, and area under the curve (AUC) of the OGTT graph. Adverse pregnancy outcomes were defined as a composite of preterm birth, macrosomia, large for gestational age, low APGAR score at 1 minute, and pregnancy-induced hypertension.

RESULTS

Overall, 257 participants were diagnosed with GDM, with a median age of 34 years. An LPA led to three different clusters of OGTT patterns; however, there were no significant associations between the clusters and adverse pregnancy outcomes after adjusting for confounders. Notwithstanding, the risk of adverse pregnancy outcome increased with an increase in number to meet the OGTT criteria (P for trend=0.011); odds ratios in a full adjustment model were 1.27 (95% confidence interval [CI], 0.72 to 2.23), 2.16 (95% CI, 1.21 to 3.85), and 2.32 (95% CI, 0.66 to 8.15) in those meeting the 2, 3, and 4 criteria, respectively. The AUCs of the OGTT curves also distinguished the patients at risk of adverse pregnancy outcomes; the larger the AUC, the higher the risk (P for trend=0.007).

CONCLUSION

The total number of abnormal values and calculated AUCs for the 100-g OGTT may facilitate tailored management of patients with GDM by predicting adverse pregnancy outcomes.

Low glucose at 3-hour 100 gram oral glucose tolerance test: implications for glucose control

OBJECTIVE

To assess the clinical significance of a low 180-minute glucose value in a 100 g oral glucose tolerance test (OGTT) and a single high abnormal value.

METHODS

A retrospective cohort study. The study group included women with 180-minute plasma glucose levels of ≤60 mg/dL and one abnormal value in the OGTT. The control group was comprised of women with one abnormal value in the OGTT and normal 180-minute glucose value. The primary outcome was glycemic control, defined as fasting blood glucose measurements > 90 mg/dL or post-prandial glucose values >140 mg/dL or 120 mg/dL (one-hour and two-hour post-prandial, respectively) in >30% of the measurements. Secondary outcomes were the rate of insulin treatment and the perinatal outcome consisting of birthweight, large-for-gestational-age, and polyhydramnios.

RESULTS

Three hundred and one women were included, 143 in the study group and 158 in the control group. Pre-pregnancy BMI, first trimester fasting glucose levels, previous GDM, and familial diabetes were similar for both groups. Suboptimal glycemic control was more prevalent among the women in the study group (14% vs. 5.1%, respectively, p= .01). The need for insulin treatment was similar in both groups.

CONCLUSIONS

Women with one abnormal value and a 180-minute hypoglycemia in the OGTT are at increased risk for suboptimal glycemic control.

Oral Glucose Tolerance Test Results in Pregnancy Can Be Used to Individualize the Risk of Future Maternal Type 2 Diabetes Mellitus in Women With Gestational Diabetes Mellitus

OBJECTIVE

We aimed to quantify the risk of future maternal type 2 diabetes mellitus (T2DM) in women with gestational diabetes mellitus (GDM) based on the type and number of abnormal 75-g oral glucose tolerance test (OGTT) values and the diagnostic criteria used for the diagnosis of GDM.

RESEARCH DESIGN AND METHODS

We conducted a population-based retrospective cohort study of all nulliparous women with a live singleton birth who underwent testing for GDM using a 75-g OGTT in Ontario, Canada (2007-2017). We estimated the incidence rate (per 1,000 person-years), overall risk (expressed as adjusted hazard ratio [aHR]), and risk at 5 years after the index pregnancy of future maternal T2DM. Estimates were stratified by the type and number of abnormal OGTT values, as well as by the diagnostic criteria for GDM (Diabetes Canada [DC] vs. International Association of the Diabetes and Pregnancy Study Groups [IADPSG] criteria).

RESULTS

A total of 55,361 women met the study criteria. The median duration of follow-up was 4.4 (interquartile range 2.8-6.3; maximum 10.3) years. Using women without GDM as reference (incidence rate 2.18 per 1,000 person-years), women with GDM were at an increased risk of future T2DM; this risk was greater when using the DC compared with the IADPSG criteria (incidence rate 18.74 [95% CI 17.58-19.90] vs. 14.07 [95% CI 13.24-14.91] per 1,000 person-years, respectively). The risk of future maternal T2DM increased with the number of abnormal OGTT values and was highest for women with three abnormal values (incidence rate 49.93 per 1,000 person-years; aHR 24.57 [95% CI 21.26-28.39]). The risk of future T2DM was also affected by the type of OGTT abnormality: women with an abnormal fasting value had the greatest risk, whereas women with an abnormal 2-h value had the lowest risk (aHR 14.09 [95% CI 12.46-15.93] vs. 9.22 [95% CI 8.19-10.37], respectively). Similar findings to those described above were observed when the risk of T2DM at a fixed time point of 5 years after the index pregnancy was considered as the outcome of interest.

CONCLUSIONS

In women with GDM, individualized information regarding the future risk of T2DM can be provided based on the type and number of abnormal OGTT values, as well as the diagnostic criteria used for the diagnosis of GDM.

Do patients with a single abnormal OGTT value need a globally admitted definition such as "borderline GDM"? Pregnancy outcomes of these women and the evaluation of new inflammatory markers

INTRODUCTION

One of the approaches to diagnose Gestational Diabetes Mellitus (GDM) is to detect two or more elevated values in 3-h Glucose Tolerance Test (OGTT) after an abnormal 50 gr Glucose Challenge Test (GCT). Patients with single elevated OGTT generally postulated as healthy; however, these patients could experience adverse perinatal and maternal issues more frequently. We aimed to investigate the maternal and neonatal outcomes of women with single abnormal OGTT primarily by comparing these women with healthy controls and GDM patients. Secondarily; Mean Platelet Volume (MPV), Platelet Distribution Width (PDW), Neutrophil to Lymphocyte Ratio (NLR) and Platelet to Lymphocyte Ratio (PLR) which were defined as novel inflammatory markers recently, were evaluated among these women within the first trimester and before delivery values whether these markers could use as a predictive marker of GDM.

MATERIALS AND METHODS

A retrospective cohort study was achieved in Bursa Yuksek Ihtisas Education and Training Hospital between January 2016 and April 2020. Patients who had GCT and OGTT at 24th-28th weeks of gestation were reviewed. Patients with GDM, women with single elevated OGTT value, and women with normal OCT values were recruited at the study as groups 1, 2, and 3 respectively. Maternal-neonatal outcomes and postpartum complications were reviewed from hospital registry system. Each complication were accumulated in a group entitled peripartum complication (a patient who had more than 1 complication for example preeclampsia and acute fetal distress was added in the peripartum complication group as one patient).The novel inflammatory markers were evaluated as NLR and PLR, and thrombocyte parameters as MPV and PDW were compared within the groups, and between the groups individually in the time period of first trimester and before delivery.

RESULTS

A total of 10,579 patients were screened with OCT, of these a total of 1718 patients' results were between 140 mg/dl and 199 mg/dl. The numbers of the women who diagnosed GDM and who had single elevated OGTT were 508 and 469 respectively. Numbers of the patients who gave birth in our hospital and whose data were reviewed adequately were 464 in groups 1, 406 in group 2, and 768 in group 3.Patients with single elevated OGTT had increased rates of peripartum complication, acute fetal distress (AFD), IUGR, preterm delivery, cesarean delivery rate, macrosomia, labor arrest, blood component transfusion, post-partum complication and stillbirth than healthy controls. Statistical analysis of comparison between group 2 and 3 has revealed that; patients with single elevated OGTT had more peripartum complication (p = .032; odds ratio [OR] = 1.2, 95% CI: 1.02-1.54), had more babies with macrosomia (p < .001; [OR] = 1.7, 95% CI: 1.2-2.4), had more postpartum complication (p = .040; [OR] = 3, 95% CI: 0.997-9.1), and had higher cesarean rates (p < .001; [OR] = 1.29, 95% CI: 1.1-1.4).Evaluating the first trimester CBC parameters between groups; only PLR differed statistically significant in GDM patients. These parameters before delivery were also analyzed PLR and NLR values did not differ between all groups, on the other hand; MPV values were higher and PDW values were lower in healthy controls comparing GDM and single elevated OGTT group.

CONCLUSION

Patients with single elevated OGTT had a higher risk of maternal and neonatal consequences than women with normal OCT, which was comparable levels to patients with GDM. These patients should not be underestimated and could be classified as an individual diagnose such as "Borderline GDM." To intervene in these patients with dietary advice and lifestyle changes like exercise could decrease neonatal and maternal adverse outcomes.

The association between gestational impaired glucose tolerance and hyperglycemic markers: A prospective study

OBJECTIVE

To investigate the association between gestational impaired glucose tolerance (GIGT), and laboratory and clinical hyperglycemic markers.

METHODS

A prospective study in Holon between 2017 and 2019. Women with a singleton term delivery and one abnormal value in their last three oral glucose tolerance test measurements (OGTTs; GIGT group, n = 60) were compared with control women with normal glucose challenge test (GCT) and/or OGTT measurements (n = 60). Primary outcomes were elevated cord-blood C-peptide (>90th percentile), maternal hemoglobin A1c (HbA1c), abnormal HbA1c (>5.7%), and neonatal skinfold thickness. Secondary outcomes included large for gestational age (LGA).

RESULTS

Women in the GIGT group were older (33.3 ± 5.3 vs 31.1 ± 4.8 years; P = 0.019), and had a higher rate of LGA (26.7% vs 6.7%; P = 0.005), macrosomia (13.3% vs 0%; P = 0.006), elevated C-peptide (16.7% vs 1.7%, P = 0.008), and abnormal HbA1c (13.3% vs 0%, P = 0.006). Skinfold thickness was also significantly higher in the GIGT group. HbA1c (adjusted odds ratio [aOR], 10.48; 95% confidence interval [CI], 1.19-91.91; P = 0.033) and GIGT (aOR, 11.43; 95% CI, 1.78-73.39; P = 0.01) were independently associated with LGA.

CONCLUSION

Women with GIGT on OGTT demonstrated "hyperglycemic characteristics" relative to those with normal GCT and/or OGTT.

Progression to Gestational Diabetes Mellitus in Pregnant Women with One Abnormal Value in Repeated Oral Glucose Tolerance Tests

BACKGROUND

Women with one abnormal value (OAV) in a 100 g oral glucose tolerance test (OGTT) during pregnancy are reported to have an increased risk of adverse pregnancy outcomes. However, there is limited data about whether women with OAV will progress to gestational diabetes mellitus (GDM) when the OGTT is repeated.

METHODS

To identify clinical and metabolic predictors for GDM in women with OAV, we conducted a retrospective study and identified women with OAV in the OGTT done at 24 to 30 weeks gestational age (GA) and repeated the second OGTT between 32 and 34 weeks of GA.

RESULTS

Among 137 women with OAV in the initial OGTT, 58 (42.3%) had normal, 40 (29.2%) had OAV and 39 (28.5%) had GDM in the second OGTT. Maternal age, prepregnancy body mass index, weight gain from prepregnancy to the second OGTT, GA at the time of the OGTT, and parity were similar among normal, OAV, and GDM groups. Plasma glucose levels in screening tests were different (151.8±15.7, 155.8±14.6, 162.5±20.3 mg/dL, P<0.05), but fasting, 1-, 2-, and 3-hour glucose levels in the initial OGTT were not. Compared to women with screen negative, women with untreated OAV had a higher frequency of macrosomia.

CONCLUSION

We demonstrated that women with OAV in the initial OGTT significantly progressed to GDM in the second OGTT. Clinical parameters predicting progression to GDM were not found. Repeating the OGTT in women with OAV in the initial test may be helpful to detect GDM progression.

Gestational impaired glucose tolerance (GIGT)-induced suppression of fetal thyroid secretion: effect on fetal outcome

INTRODUCTION

Gestational impaired glucose tolerance (GIGT) is a milder form of gestational diabetes mellitus (GDM), which is often poorly managed. Although, GDM is known to be associated with increased incidence of thyroid dysfunction, no study has been done to study the effect of GIGT on thyroid status and its effect on fetal outcome. Here, we carried out a study to assess thyroid function and glycemic status in both maternal and cord blood of the subjects with GIGT, and to find their association with the fetal outcome.

MATERIALS AND METHODS

Women who came to the hospital for safe confinement during 37-40th weeks of gestation were recruited in the study. Based on the 2 hours post prandial blood glucose levels with 75 grams OGTT, done at 24-28 weeks of gestation, all the subjects were stratified into two groups: (1) Cases or GIGT group - women with blood glucose levels between 120 and 140 mg/dl and (2) Controls - women with blood glucose levels of less than 120 mg/dl. Three milliliters of venous blood was collected from mothers and 3 ml of cord blood was collected during delivery. New-borns were assessed for birth weight, head circumference, abdominal circumference, thigh circumference, and crown-heel length. Glycated hemoglobin was carried out using immunoturbidimetry (DiaSys Diagnostic Systems GmbH, Holzheim, Germany) and fructosamine was estimated using dye binding method (Biosystems, Spain). Estimation of total T₃ (TT3), free T₃ (FT₃), total T₄ (TT₄), free T₄ (FT₄), and TSH was done by chemiluminescence in Siemens Advia Centaur CP using competitive immunoassay.

RESULTS

Although within the normal reference range, GIGT mothers had higher concentration of free and total T₄ than controls. Cord fructosamine levels were significantly higher in babies of GIGT mothers than controls, indicating the reflection of maternal hyperglycemia. There was a positive correlation between the maternal glycated hemoglobin and cord blood fructosamine in the GIGT group. Statistically significant lower levels of total T₃ and T₄ with high TSH levels were found in babies with GIGT mothers, indicating the suppressive effect of maternal hyperglycemia on fetal thyroid function. Birth weight, head circumference, and thigh circumference were significantly higher in babies born to mothers with GIGT, which may be a combined effect of maternal hyperglycemia and fetal thyroid suppression.

CONCLUSIONS

Maternal hyperglycemia, even in milder form of GIGT may cause suppression of fetal thyroid function. Both these factors may predispose to change in fetal anthropometry, leading to a large baby. Therefore, it is recommended to evaluate maternal and cord thyroid function for timely management strategies.

Characteristics of abnormal oral glucose tolerance test in GDM diagnosis and clinical correlation

OBJECTIVES

To describe the characteristics of abnormal oral glucose tolerance test (OGTT) values at gestational diabetes mellitus (GDM) diagnosis and their associations with clinical characteristics, and to evaluate the effect on GDM diagnosis if any OGTT value was omitted.

MATERIALS AND METHODS

A cross-sectional study was conducted in 415 women diagnosed with GDM. The OGTT results were recorded and analyzed.

RESULTS

Of the 415 included women, mean gestational age at GDM diagnosis was 19.2 weeks and 57.6% were diagnosed before 20 weeks. The highest proportions of abnormal values were found at the 1st and 2nd hour (85.3% and 96.6%, respectively). If the 3rd hour OGTT value was omitted, 16.7% of GDM cases would be missed. Number of abnormal OGTT values and abnormal FPG were significantly associated with obesity. Only pre-pregnancy overweight and obesity independently associated with insulin requirement (adjusted OR: 2.28, 95%CI: 1.02-5.06; p = .044; and adjusted OR: 6.29, 95%CI: 2.67-14.85; p < .001, respectively).

CONCLUSIONS

Over half of the GDM women had three or four abnormal OGTT values. Omission of the 3rd hour OGTT value would result in 16.7% of patients not being diagnosed with GDM. Number of abnormal OGTT values and abnormal FPG were associated with obesity, and insulin requirement was associated with pre-pregnancy overweight and obesity.

Single abnormal value on 3-hour oral glucose tolerance test during pregnancy is associated with adverse maternal and neonatal outcomes: a systematic review and metaanalysis

OBJECTIVE DATA

The purpose of this study was to determine whether women with 1 abnormal value on 3-hour 100-g oral glucose tolerance test are at an increased risk for adverse pregnancy outcomes.

STUDY

Gestational diabetes mellitus is diagnosed by a 2-step method, with a 3-hour, 100-g oral glucose tolerance test that is reserved for women with an abnormal 1-hour, 50-g glucose challenge test. Although the increased maternal-fetal morbidity with gestational diabetes mellitus is well established, controversy remains about the risk that is associated with an isolated abnormal value during a 3-hour, 100-g oral glucose tolerance test.

STUDY APPRAISAL AND SYNTHESIS METHODS

Prospective and retrospective studies that evaluated the maternal and perinatal impact of 1 abnormal glucose value during a 3-hour, 100-g oral glucose tolerance test were identified with the use of computerized databases. Data were extracted and quantitative analyses were performed.

RESULTS

Twenty-five studies (7 prospective and 18 retrospective) that met criteria for metaanalysis included 4466 women with 1 abnormal glucose value on oral glucose tolerance test. Patients with 1 abnormal glucose value had significantly worse pregnancy outcomes compared with women with zero abnormal values with the following pooled odds ratios: macrosomia, 1.59 (95% confidence interval, 1.16-2.19); large for gestational age, 1.38 (95% confidence interval, 1.09-1.76); increased mean birthweight, 44.5 g (95% confidence interval, 8.10-80.80 g); neonatal hypoglycemia, 1.88 (95% confidence interval, 1.05-3.38); total cesarean delivery, 1.69 (95% confidence interval, 1.40-2.05); pregnancy-induced hypertension, 1.55 (95% confidence interval, 1.31-1.83), and Apgar score of <7 at 5 minutes, 6.10 (95% confidence interval, 2.65-14.02). There was also an increase in neonatal intensive care unit admission and respiratory distress syndrome. Similar results were seen that compared 1 abnormal glucose value to a population with a normal 1-hour 50-g glucose challenge test (normal glucose screen). With the exception of birthweight, outcomes of patients with 1 abnormal glucose value were similar to outcomes of patients with gestational diabetes mellitus.

CONCLUSION

Women with 1 abnormal value on 3-hour, 100-g oral glucose tolerance test have a significantly increased risk for poor outcomes comparable with women who have gestational diabetes mellitus.

Maternal hyperglycemia and the 100-g oral glucose tolerance test

OBJECTIVES

To compare the characteristics of pregnant women with hyperglycemia according to the severity of glucose intolerance using the 100-g oral glucose tolerance test (OGTT) and to demonstrate the need to manage the condition of women with mild hyperglycemia.

MATERIALS AND METHODS

In this retrospective cohort study, a total of 258 women at high risk of gestational diabetes (GDM) based on a positive 50-g oral glucose challenge test (OGCT) were classified into 0+, 1+, 2+, 3+, and 4+ groups according to the number of abnormal plasma glucose values on the 100-g OGTT. The clinical characteristics of the groups were compared.

RESULTS

The rates of advanced maternal age (≥ 35 years), multiparity, prior history of GDM, preterm birth, cesarean delivery, and elevated body mass index were all positively correlated with the number of abnormal plasma glucose values on the OGTT (p < 0.05 for all variables). After adjusting for confounding factors, the fasting plasma glucose levels predicted birth weight in 44.4%, 48.4%, and 58.6% of the women in the positive 50-g OGCT group, the 0+ group, and the 1+ group, respectively. Weight gain during pregnancy predicted birth weight in 42%, 44.6%, and 37.6% of the women in the positive 50-g OGCT group, the 0+ group, and the 2+ group, respectively (p < 0.001 in each case).

CONCLUSIONS

These data demonstrate that the detection and management of mild hyperglycemia below the current diagnostic criteria of GDM as well as GDM diagnosed using the 100-g OGTT are necessary for improving pregnancy outcomes.

Effect of different degrees of glucose intolerance on maternal and perinatal outcomes

OBJECTIVE

To evaluate the effect of markedly elevated 50-g glucose loading test (GLT) (>or=200 mg/dL) and equivocal 100-g GLT (one abnormal value) results on maternal and perinatal outcomes.

METHODS

Retrospective analysis of 2029 singleton pregnancies screened for gestational diabetes mellitus (GDM). Maternal and perinatal outcomes in five different groups with different degrees of glucose intolerance were compared. First group consisted of patients with normal 50-g test, second group was formed by patients with abnormal 50-g glucose test but a normal 100-g test. Third group included patients with one abnormal value after 100-g test. Patients in the fourth group were diagnosed to have GDM after an abnormal 100-g test. Patients in the fifth group had a value >or=200 mg/dL after 50-g test and were diagnosed to have GDM.

RESULTS

Macrosomia and large for gestational age incidence were highest in the group with one elevated glucose tolerance test (GTT) value. Hospitalisation rates, hypoglycemia, hyperbilirubinemia and polycythemia were more common in neonates born to mothers with one elevated GTT value and to mothers with a GLT > 200 mg/dL.

CONCLUSION

Adverse maternal and perinatal outcomes in patients with one elevated GTT value and in patients with a GLT value > 200 mg/dL warrant close glucose monitoring and treatment in these groups even in the absence of a diagnostic abnormal GTT.

Gestational diabetes: the need for a common ground

Gestational diabetes mellitus is a substantial and growing health concern in many parts of the world. Certain populations are especially vulnerable to developing this condition because of genetic, social, and environmental factors. Gestational diabetes has serious, long-term consequences for both baby and mother, including a predisposition to obesity, metabolic syndrome, and diabetes later in life. Early detection and intervention can greatly improve outcomes for women with this condition and their babies. Unfortunately, screening and diagnostic tests are not uniform worldwide, which could lead not only to underdiagnosis but also undermanagement of the illness. Here, we report the controversies surrounding the causes, screening, diagnosis, management, and prevention of gestational diabetes, and give specific recommendations for research studies to address the major issues of this medical condition.

Establishing diagnosis of gestational diabetes mellitus: Impact of the hyperglycemia and adverse pregnancy outcome study

The diagnosis of gestational diabetes mellitus (GDM) remains controversial, without universal acceptance of a particular set of diagnostic criteria, and, in fact, a lack of consensus as to whether this is an entity worth diagnosis. Some of the debate derives from differences of opinion about what degree of glucose intolerance should be labeled as GDM. Therefore, it is to be expected that there are different viewpoints on how to detect and screen for GDM. It is believed that early diagnosis will result in a significant improvement in perinatal outcome in these patients. In this review, we discuss the current data concerning screening for GDM and new strategies for GDM diagnosis in light of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study.

Is fasting glucose level during oral glucose tolerance test an indicator of the insulin need in gestational diabetes?

Maintenance of a good metabolic control improves foetal and maternal outcomes in gestational diabetes mellitus (GDM). The aim of this study is to investigate the utility of diagnostic oral glucose tolerance test (OGTT) in prediction of the need of insulin in patients with GDM. One hundred and fifty five consecutive patients with GDM were included in the study. Patients were ordered MNT first. Those who failed to maintain glycemic targets were treated with insulin. Glucose levels obtained from the diagnostic OGTT were evaluated regarding the need of insulin during the rest of pregnancy. Fasting, 1h and 3h post-load glucose levels were significantly elevated in patients who required insulin. Multivariate analysis showed that fasting glucose level on OGTT was an independent predictor for the insulin need. A cut-off value of 105mg/dl had a fair specificity (91.89%) and positive predictive value (80.64%) for the prediction of patients who required insulin during the rest of their pregnancy. Our results suggest that fasting glucose level on OGTT is a predictor of the need for insulin treatment in GDM. A cut-off level of 105mg/dl seems to effectively determine high-risk patients for additional treatment other than MNT in GDM.

Isolated hyperglycemia at 1 hour on oral glucose tolerance test in pregnancy resembles gestational diabetes mellitus in predicting postpartum metabolic dysfunction

OBJECTIVE

Gestational impaired glucose tolerance (GIGT), defined by a single abnormal value on antepartum 3-h oral glucose tolerance test (OGTT), is a metabolically heterogeneous disorder. Indeed, the antepartum metabolic phenotype of women with a single abnormal value at 1 h during the OGTT (1-h GIGT) resembles that of women with gestational diabetes mellitus (GDM), whereas GIGT at 2 or 3 h (2/3-h GIGT) is similar to normal glucose tolerance (NGT). Thus, we hypothesized that 1-h GIGT would be associated with the same adverse outcomes as GDM, i.e., increased infant birth weight and postpartum metabolic dysfunction.

RESEARCH DESIGN AND METHODS

A total of 361 women underwent an antepartum glucose challenge test (GCT) and a 3-h OGTT, assessment of obstetrical outcome at delivery, and metabolic characterization by OGTT at 3 months postpartum. The antepartum GCT/OGTT identified five study groups: GDM (n = 97), 1-h GIGT (n = 28), 2/3-h GIGT (n = 34), abnormal GCT NGT (abnormal GCT with NGT on OGTT) (n = 128), and normal GCT NGT (normal GCT with NGT on OGTT) (n = 74).

RESULTS

Caesarian section rate was higher in women with 1-h GIGT, but birth weight did not differ significantly between the non-GDM groups (P = 0.1978). At 3 months postpartum, glycemia (area under the glucose curve) progressively increased across the groups from normal GCT NGT to abnormal GCT NGT to 2/3-h GIGT to 1-h GIGT to GDM (P < 0.0001), while both insulin sensitivity (IS(OGTT)) and beta-cell function (insulinogenic index/homeostasis model assessment of insulin resistance [HOMA-IR]) progressively decreased (P = 0.002 and P < 0.0001, respectively). The strongest independent negative predictors of insulinogenic index/HOMA-IR were GDM (t = -4.1, P < 0.0001) and 1-h GIGT (t = -3.8, P = 0.0002).

CONCLUSIONS

Like GDM, 1-h GIGT is associated with postpartum glycemia, insulin resistance, and beta-cell dysfunction.

Women with one elevated 3-hour glucose tolerance test value: are they at risk for adverse perinatal outcomes?

OBJECTIVE

The purpose of this study was to examine whether women with one elevated value of the 3-hour glucose tolerance test are at increased risk for adverse perinatal outcomes.

STUDY DESIGN

This was a retrospective cohort study of singleton pregnancies that were screened for gestational diabetes mellitus with the use of the glucose loading test and with a glucose tolerance test for follow up, if screened values were positive. Perinatal outcomes in women with one elevated glucose tolerance test value were compared with the outcomes in women who screened negative by glucose loading test. The chi-square test was used to compare categorical outcomes, and multivariate logistic regression analysis was used to control for potential confounding factors; a P value of < .05 indicated statistical significance.

RESULTS

Of 14,036 women who met the study criteria, women with one elevated glucose tolerance test value exhibited higher rates of cesarean delivery (in nulliparous women only), preeclampsia, chorioamnionitis, birth weight > 4000 g and > 4500 g, and neonatal admission to the intensive care nursery as compared with women who screened negative (P < .05 for all).

CONCLUSION

Although women with one elevated glucose tolerance test value are not diagnosed with gestational diabetes mellitus, they are still at risk for adverse perinatal outcomes.