1-hour Glucose Challenge Test Research Articles

A Pilot Study Using Continuous Glucose Monitoring among Patients with a Low 1-Hour Glucose Challenge Test Result versus Controls to Detect Maternal Hypoglycemia.

A low 1-hour glucose challenge test (GCT) result (<10th percentile for population) has been associated with neonatal morbidity, including small-for-gestational-age birth weight, and it is hypothesized that underlying maternal hypoglycemia may contribute to this neonatal morbidity. We sought to assess whether eligible patients would undergo continuous glucose monitoring to allow comparison of maternal hypoglycemia between those with a low GCT result versus controls. This exploratory study enrolled patients who completed a GCT between 24 and 30 weeks' gestation from June to September 2022. English- or Spanish-speaking participants aged ≥18 years wore a blinded continuous glucose monitor (CGM) for 10 days. There were 10 participants each in the low GCT (<82 mg/dL) and normal GCT group. Proportions were calculated to determine recruitment rates and describe the low versus normal glycemic groups across clinical and sociodemographic characteristics. Maternal hypoglycemia, defined using various proposed thresholds, was analyzed as continuous data (time duration) with Student's t-tests and categorical data (number of episodes) with chi-square tests and bivariate analyses were performed comparing participants with a low versus normal GCT. Primary outcome measures were recruitment, enrollment, and adherence rates, and overall glycemic values for each group. Of 64 eligible patients, 58 (91%) were approached, and of them, 20 (35%) were enrolled. All 20 participants had CGM data to review with 100% adherence. Average glucose values were similar between participants in the low GCT and normal GCT groups (111.7 ± 18.0 vs. 111.6 ± 11.7 mg/dL, p = 0.99), and participants with a low GCT value did not demonstrate more hypoglycemia than those with a normal GCT value across five proposed thresholds on CGM analysis. In this pilot study, participants wore blinded CGMs to collect glycemic data, and those with a low GCT result did not experience more hypoglycemia than those with a normal GCT on CGM analysis. · Study participants wore continuous glucose monitors in blinded mode to gather glycemic data with 100% adherence.. · Participants with a low GCT result (<82 mg/dL) as compared with those with a normal GCT result were not more likely to demonstrate maternal hypoglycemia using several thresholds on CGM analysis.. · In our cohort, there were few participants in either glycemic group who reported food insecurity or lived in a food desert..

1163 Maternal and neonatal outcomes with severely elevated 1-hour glucose challenge test

1163 Maternal and neonatal outcomes with severely elevated 1-hour glucose challenge test

Time to Completion of Two-Step Screening for Gestational Diabetes and Adverse Outcomes.

This study aimed to ascertain whether the length of time to complete the gestational diabetes mellitus (GDM) screening was associated with adverse neonatal outcomes. This was a retrospective cohort study of singleton, nonanomalous individuals who were screened for GDM at ≥24 weeks' gestation at an academic hospital system. We compared outcomes among people who were diagnosed with GDM and completed the 3-hour glucose tolerance test (GTT) ≤14 second versus >14 days from the 1-hour glucose challenge test (GCT). The primary outcome was a composite adverse neonatal outcome of the following: large for gestational age, shoulder dystocia, birth injury, respiratory distress, hypoglycemia, or fetal/neonatal death. The secondary outcomes included several individual neonatal and maternal morbidities. Multivariable Poisson's regression models were used to evaluate the association. Adjusted relative risk (aRR) and 95% confidence intervals (CI) were calculated. Among the 313 individuals who completed the two-step screening for GDM and had an 1-hour GCT ≥ 135 mg/dL; of them, 171 (54.6%) completed the 3-hour GTT ≤14 days, 142 (45.4%) completed the 3-hour GTT > 14 days. Overall rate of the primary outcome was 44.1%. After multivariable adjustment, the risk of the primary outcome was similar between people who completed the two-step method in ≤14 versus >14 days (aRR = 1.11, 95% CI = 0.81-1.52). There was no significant difference in all secondary adverse outcomes between the two groups. Subgroup analyses, limited to people diagnosed with GDM (N = 89, 23.4%), also found similar results as the full analyses. Among individuals who completed the two-step screening for GDM, completion of the 3-hour GTT within ≤14 versus ≥ 14 days was not associated with an increase rate of the adverse outcomes. · Among pregnant people in an academic practice, 50% of people with abnormal 1-hour GTT completed GDM two-step screening in 14 days.. · Longer length of time to completion of diagnostic testing for GDM was not associated with an increased rate of adverse outcomes.. · Pregnant people that were diagnosed with GDM and completed the two-step method in >14 days did not have worse perinatal outcomes..

The association between a low 50-gram, 1-hour glucose challenge test value and neonatal morbidity

Objective To evaluate the association between a low 50-gram, 1-hour glucose challenge test (GCT) value and adverse maternal and neonatal outcomes among patients receiving care at a single center tertiary care academic hospital. Methods We performed a retrospective cohort study of pregnant patients with a documented result of a 50-gram, 1-hour GCT performed ≥24 weeks 0 days gestation at a single tertiary care academic hospital from 2013–2021. Patients with a low GCT value, defined as cohort specific ≤10th percentile (<82 mg/dL), were compared to patients with a GCT value ≥82 mg/dL who were not diagnosed with gestational diabetes (GDM) to examine adverse maternal and neonatal outcomes. Additionally, these comparisons were repeated across patients with low GCT (<82 mg/dL), those with a GCT ≥82 mg/dL without diagnosis of GDM (heretofore referred to as normal glycemic screening) and patients diagnosed with GDM. Our primary outcome was a composite neonatal morbidity variable, inclusive of stillbirth, neonatal death, neonatal hypoglycemia with neonatal intensive care unit (NICU) admission, neonatal hyperbilirubinemia with NICU admission, respiratory distress with NICU admission, and/or small for gestational age (SGA). Multivariable logistic regression modeling was used to examine the association of low GCT value and the composite neonatal morbidity outcome, compared to those with the normal glycemic screening. Results Of 36,342 eligible patients, 3,789 (10.4%) had a low GCT value of <82 mg/dL, 30,729 (84.6%) had a GCT value ≥82 mg/dL and were not diagnosed with GDM, and 1,824 (5.0%) had a diagnosis of GDM. Patients with a low GCT value were significantly less likely to be diagnosed with hypertensive disorder of pregnancy (HDP) (12.4% vs 16.3%, p < .01), undergo cesarean delivery (22.8% vs 29.9%, p < .01), or experience postpartum hemorrhage (7.8% vs 9.4%, p < .01) as compared to patients with normal glycemic screening. Compared to newborns whose mothers had normal glycemic screening, newborns of mothers with a low GCT value were significantly more likely to experience the composite morbidity outcome (OR 1.17; 95% CI 1.08–1.27); this persisted after adjusting for potential confounders (aOR 1.18; 95% CI 1.09–1.29). Conclusion A low maternal GCT value after 24 weeks gestation is significantly associated with an increased risk of morbidity in the newborn, driven by higher rates of SGA. Patients with a low GCT value may have underlying maternal hypoglycemia or other glycemic dysregulation affecting fetal development and may benefit from enhanced antenatal surveillance.

Evaluation of Early Screening for Diabetes Mellitus in Pregnancy with Hemoglobin A1c

AbstractEarly diabetes screening is recommended for high-risk pregnant women risk via a 1-hour glucose challenge test (1-hour GCT). Hemoglobin A1c (HbA1c) can be obtained with initial obstetric laboratories. We sought to examine the relationship between HbA1c and 1-hour GCT for early diabetes screening in pregnancy.This is a retrospective cohort study of 204 high-risk pregnant women who underwent early HbA1c and 1-hour GCT. Simple logistic regression analysis was performed to predict abnormal 1-hour GCT and diagnosis of diabetes using HbA1c.A total of 158 (77.5%), 44 (21.5%), and 2 (1%) women had HbA1c of less than 5.7, 5.7 to 6.4, and 6.5% or higher, respectively. Seven of 158 (4.4%) women with HbA1c less than 5.7% and 8 of 44 (18.2%) with HbA1c of 5.7 to 6.4% had a diagnosis of diabetes. A positive correlation between early HbA1c and 1-hour GCT was detected. Logistic regression showed HbA1c significantly predicted the risk of diabetes but was not a good predictor of abnormal 1-hour GCT. HbA1c of 5.5% or less had a 97% or higher negative predictive value for early diabetes in pregnancy.There is a positive correlation between HbA1c and 1-hour GCT for the early screening of diabetes in pregnancy. Women with early HbA1c ≤ 5.5% could forego further testing in early pregnancy.

1186-P: Can an Early GCT Value and A1C Eliminate the Need for Repeat GCT Testing during Second-Trimester Pregnancy?

Background: While A1c is a widely used marker for IDDM and NIDDM, its clinical use in gestational diabetes mellitus (GDM) is not well elucidated. We aimed to evaluate if an A1c and an early glucose challenge test (GCT) can be used to identify patients who may forgo repeat 2nd trimester GCT testing. Methods: This was a retrospective cohort study of patients eligible for early GDM screening who had a negative screening at ≤20 weeks gestation and delivered at a single center between 2016-2020. The primary outcome was GDM in the 2nd trimester by Carpenter &amp; Coustan criteria. Receiver operating characteristic (ROC) curve analyses were performed to compare the ability of early GCT value, and in combination with A1c to predict the primary outcome. Results: Of the 2,025 patients eligible for early GDM screening, 722 met inclusion criteria. Of these, 583 had a 1-hour GCT, 178 had an A1c, and 38 had both. The prediction of GDM diagnosis in the 2nd trimester using an early GCT value, A1c, and both on a ROC plot produced an area under the curve (AUC) of 0.753, 0.659, and 0.672, respectively. The highest A1c where no patients were diagnosed with GDM in 2nd trimester was 4.5%, but of the 43 patients with A1c ≤5.1%, 1 (2.3%) was diagnosed with GDM in the 2nd trimester. Conclusion: Early GCT value alone was a better predictor of GDM in 2nd trimester than a combination of GCT with A1c. A1c alone was a poor predictor. Disclosure J.A.Beacham: None. K.C.Bodycot: None. R.Huang: None. H.B.Al-kouatly: None. R.Mclaren: None.

Hemoglobin A1c as a Substitute for Oral Glucose Testing in Early Pregnancy Screening.

Current recommendations for individuals with risk factors for gestational diabetes mellitus (GDM) call for screening in early pregnancy. However, there is currently no clear consensus on a specific screening modality. This study evaluates whether a hemoglobin A1c (HbA1c) screening in individuals with risk factors for gestational diabetes (GDM) could be used instead of an early 1-hour glucose challenge test (GCT). We hypothesized that the HbA1c could replace 1-hour GCT in early pregnancy evaluation STUDY DESIGN: This is a prospective observational trial at a single tertiary referral center of women with at least one risk factor for GDM who were screened at <16 weeks of gestation with both 1-hour GCT or HbA1c. Exclusion criteria include: previous diagnosis of diabetes mellitus, multiple gestation, miscarriage, or missing delivery information. The diagnosis of GDM was made by a 3-hour 100-g glucose tolerance test, using the Carpenter-Coustan criteria (at least two results >94, 179, 154, and 139 mg/dL for fasting, 1-, 2-, and 3-hour values, respectively), 1-hour GCT > 200 mg/dL, or HbA1c > 6.5%. A total of 758 patients met inclusion criteria. A total of 566 completed a 1-hour GCT and 729 had an HbA1c collected. The median gestational age at testing was 91/7 weeks (range: 40/7-156/7 weeks]. Twenty-one participants were diagnosed with GDM at <16 weeks' GA. The receiver operating characteristic (ROC) curves identified the optimal valves for a positive screen for an HbA1c > 5.6%. The HbA1c had a sensitivity of 84.2%, a specificity of 83.3%, and a false positive rate of 16.7% (p < 0.001). The area under the ROC curve for the HbA1c was 0.898. Gestational age of delivery was slightly earlier with individuals with an elevated HbA1c but no other changes in delivery or neonatal outcomes. Contingent screening improved specificity (97.7%) and decreased false positive rate to 4.4%. HbA1c may be a good assessment in early pregnancy for gestational diabetes. · HbA1c is a rational assessment in early pregnancy.. · An HbA1c > 5.6% is associated with gestational diabetes.. · Contingent screening limits the need for additional testing..

Initiation of Oral Agents Versus Insulin as First-Line Therapy for Gestational Diabetes Mellitus [ID: 1360154

INTRODUCTION: Although the American College of Obstetricians and Gynecologists recommends insulin as first-line pharmacologic treatment for gestational diabetes mellitus (GDM) since 2017, use of oral agents as first-line remains common. This study aims to identify patient-level factors associated with choice of initial pharmacologic treatment of GDM with oral agents compared to insulin. METHODS: Case–control study of 617 patients with White's class A2 GDM treated at a single academic center in a comprehensive GDM treatment program, 2011–2018. Pregestational diabetes and GDM not requiring medication (A1 GDM) were excluded. Case group was GDM pregnancies treated with any oral agent first-line and control group was treated with insulin as first-line treatment. Logistic regression was performed to identify patient factors associated with oral agents as first-line pharmacologic treatment. Receiver-operator characteristic (ROC) curve estimated the ability of these factors to predict initial medication choice. RESULTS: Among those with GDMA2, 80% were started on an oral agent and 20% were started on insulin. Those started initially on oral agents were more likely to be Hispanic or non-Hispanic White, be non-English speakers, have private insurance, and have normal body mass index (BMI). Factors strongly associated with starting on an oral agent rather than insulin were Hispanic ethnicity, treatment initiated later in pregnancy (&gt;28 weeks), normal BMI, and 1-hour glucose challenge test (GCT) greater than 200. The ROC derived from the adjusted logistic regression model found a predictive value of these variables for initiating oral agents of 79% (area under the curve 0.79). CONCLUSION: Patient-level factors are predictive of pharmacological agent chosen for first-line treatment of GDM. Factors that are typically associated with more difficult to control GDM, such as obesity, high values on the GCT screening test and earlier gestational age at diagnosis are more common in patients treated initially with insulin. However, some demographic factors such as Hispanic ethnicity and non-English primary language are more common among patients initiated on oral agents for treatment of GDM.

Glucose Testing in an Index Pregnancy and Outcomes in a Subsequent Pregnancy: Implications for Screening and a Novel Risk Calculator.

Our objective was to assess whether variables from an index pregnancy (PG1) can be used to guide testing for gestational diabetes mellitus (GDM) in a subsequent pregnancy (PG2) and to create a risk calculator for GDM in PG2. This was a retrospective cohort study of patients delivering ≥2 singleton gestations at >24 weeks' gestation from June 2009 to December 2018, for whom results of a 1-hour glucose challenge test (GCT) were available from PG1. Univariable and multivariable analyses were performed to evaluate factors associated with GDM in PG2. In total, 4,278 patients met the inclusion criteria. Among patients with a normal 1-hour GCT (<140 mg/dL) in PG1 (n = 3,719), 3.9% were diagnosed with GDM in PG2. In multivariable analysis of this group, GDM in PG2 was associated with higher GCT in PG1 (adjusted odds ratio [aOR]: 1.05, 95% confidence interval [CI]: 1.04-1.06), large for gestational age neonate in PG1 (aOR: 1.97, 95% CI: 1.24-3.13), and higher BMI (aOR: 1.08, 95% CI: 1.05-1.11). A novel risk calculator for GDM in PG2 was developed based on these associations. Using a risk cut-off of 15%, the calculator had a positive predictive value of 26% and a negative predictive value of 97%, with 3.2% of patients identified as "at risk". Among patients with abnormal 1-hour GCT in PG1, 38.3% (n = 214/559) had an abnormal 1-hour GCT in PG2 and 34.5% (n = 74/214) of these patients received a diagnosis of GDM. A normal 1-hour GCT in an PG1 is followed by GDM in a subsequent pregnancy in only 3.9% of cases. A novel calculator supports replacing universal screening with targeted testing in subsequent pregnancies in this population. Among patients with an abnormal 1-hour GCT in PG1, nearly 40% have an abnormal 1-hour GCT in a subsequent pregnancy. Direct diagnostic testing can be considered in such patients. · Normal GCT in a first pregnancy is associated with normal GCT in subsequent pregnancy.. · A risk calculator can target diabetes testing in a subsequent pregnancy.. · Abnormal GCT in a first pregnancy is associated with abnormal GCT in subsequent pregnancy..

Association Between 1-Hour Glucose Challenge Test Values and Infant Birth Weight in a Prospective Cohort From Dhulikhel, Nepal

ObjectivesElevated blood glucose level during pregnancy is known to be associated with adverse birth outcomes including macrosomia. However, data is lacking from low-income and low nutritional status countries like Nepal. This study examined the association between maternal glucose levels after a 1-hour 50g glucose challenge test (1-hr 50g GCT) and infant birthweight (BW) in a periurban pregnancy cohort from Dhulikhel, Nepal.MethodsA prospective cohort of singleton pregnant women (N = 195; age 26.1 ± 4.1 years) was recruited from a tertiary, periurban hospital in Nepal. All women underwent 1-hr 50g GCT between 24–29 weeks of gestation. BW was abstracted from medical records. Primary outcomes included low BW (LBW; BW < 2500g) compared to normal BW (2500g-4500g), and small for gestational age (SGA, BW < 10th percentile) and large for gestational age (LGA, BW > 90th percentile), compared to appropriate for gestational age (AGA, BW 10th-90th percentile). Using logistic regression, we estimated the odds ratios (OR) and 95% confidence intervals (CI) for the association of 1-hr 50g GCT value with each BW outcome, adjusting for apriori covariates including age, education, and pre-pregnancy BMI.ResultsThe mean GCT value in our sample was 115.5 ± 25.9 mg/dL and the mean infant BW was 2958.9 ± 412.3g. The prevalence of LBW was 13.3% (n = 26); 8.8% were SGA, and 18.1% were LGA. There was a quadratic (inverted U) association between GCT levels and BW (p = 0.08). GCT levels were higher in both women with SGA (120.2 mg/dL ± 28.1) and LGA babies (122.7 mg/dL ± 21.4), compared to women who gave birth to AGA babies (112.4 mg/dL ± 23.9), but this was only statistically significant for LGA vs. AGA (p = 0.047). After controlling for age, education, and pre-pregnancy BMI, the association between GCT and LGA was no longer significant. However, GCT value was significantly and positively associated with increased risk of LBW even after controlling for age, education, and pre-pregnancy BMI (OR = 1.03, CI: 1.01–1.05; p = 0.004).ConclusionsElevated GCT value is significantly associated with increased risk of LBW in a cohort from Nepal. Further research with larger samples is warranted to confirm these findings and clarify the underlying physiological mechanisms involved.Funding SourcesNIH/FIC.

Is an isolated abnormal 1-hour glucose challenge test associated with adverse pregnancy outcomes?

Is an isolated abnormal 1-hour glucose challenge test associated with adverse pregnancy outcomes?

Elevated Glucose Challenge Test in a Nondiabetic Index Pregnancy and Gestational Diabetes in a Subsequent Pregnancy

The aim of this study was to evaluate whether a 1-hour glucose challenge test (GCT) ≥140 mg/dL in a nondiabetic index pregnancy is associated with the development of gestational diabetes mellitus (GDM) in a subsequent pregnancy. We performed a retrospective cohort study from a single institution from June 2009 to December 2018. Women with a nondiabetic index singleton gestation who underwent a 1-hour GCT at 24 to 28 weeks and had a successive singleton delivery were included. GDM was defined by a 1-hour GCT of ≥ 200 mg/dL, ≥2 of 4 elevated values on a 3-hour GCT, or a diagnosis of GDM defined by International Classification of Disease codes in the electronic medical record. Univariable analyses were performed to evaluate the associations between an elevated 1-hour GCT result in the index pregnancy, maternal characteristics, and the development of GDM in the subsequent pregnancy. Variables found to be significant (p < 0.05) were included in multivariable analysis. A total of 2,423 women were included. Of these, 340 (14.0%) had an elevated 1-hour GCT in the index pregnancy. Women with an elevated 1-hour GCT in the index pregnancy compared with those without were significantly more likely to be older, married, privately insured, of Hispanic ethnicity or Asian race, chronically hypertensive, have a higher body mass index (BMI), have a shorter inter-pregnancy interval, and to develop GDM in the subsequent pregnancy (14.4 vs. 3.3%, p < 0.001). In multivariable analysis, an elevated 1-hour GCT (adjusted odds ratio [aOR]: 4.54, 95% confidence interval [CI]: 3.02-6.81), first-trimester BMI ≥30 kg/m2 in the index pregnancy (aOR: 3.10, 95% CI: 2.03-4.71), Asian race (aOR: 2.96, 95% CI: 1.70-5.12), Hispanic ethnicity (aOR: 2.11, 95% CI: 1.12-4.00), and increasing age (aOR: 1.07, 95% CI: 1.02-1.12) were significantly associated with an increased risk of GDM in the subsequent pregnancy. An elevated 1-hour GCT in a nondiabetic index pregnancy is associated with a fourfold increased risk of GDM in a subsequent pregnancy. · An abnormal 1 hour GCT in an index pregnancy is associated with GDM in a subsequent pregnancy.. · An abnormal 1 hour GCT may be an independent risk factor for GDM in a subsequent pregnancy.. · An abnormal 1 hour GCT is associated with a 4 fold increased risk of GDM in a subsequent pregnancy..

943 Abnormal glucose screening in an index pregnancy and gestational diabetes in a subsequent pregnancy

In a non-diabetic pregnancy, the current practice is universal screening for gestational diabetes (GDM) using a 1-hour glucose challenge test (GCT) regardless of prior history. We aimed to determine whether an abnormal 1-hour GCT from an index pregnancy (PG1) can be used to guide GDM testing in a subsequent pregnancy (PG2). This was a retrospective cohort study of women who delivered 2 singleton pregnancies at >24 weeks from June 2009-December 2018 at a single institution. All patients had an abnormal PG1 GCT result (> 140 mg/dL). GDM was defined by GCT of >200mg/dL, >2 elevated values on a 3-hour diagnostic test (Carpenter-Coustan criteria), or a diagnosis by ICD codes. Univariable and multivariable analyses (MVA) were performed to examine the relationship between GDM in PG2 with variables from PG1. Given the high likelihood of GDM in subsequent pregnancies among women with GDM in PG1, the MVA was restricted to patients who were non-diabetic in PG1. 820 women met inclusion criteria, 356 (43.4%) had an abnormal 1-hour GCT in PG2, 233 (28.4%) developed GDM in PG2, and 48 (20.6%) of patients received a diagnosis of GDM without meeting laboratory criteria (Table 1). In MVA of subjects in a non-diabetic PG1, those with GDM in PG2 were significantly more likely to have higher GCTs in PG1, be of Asian race and have had gestational hypertension (gHTN) in PG1 (Table 2). In a non-diabetic PG1, the risk of GDM in PG2 increases with PG1 GCT result, Asian race and a history of gHTN. Of all patients with an abnormal PG1 GCT, regardless of PG1 diabetic status, 43.4% had an abnormal 1-hour GCT in PG2 with over a quarter of these patients diagnosed with GDM. Furthermore, our observation that 20.6% of patients diagnosed with GDM without laboratory criteria suggests that these women are considered at higher risk and are receiving the diagnosis of GDM regardless of diagnostic criteria. Thus, consideration can be given to supplant universal screening using a 1-hour GCT with direct diagnostic testing in women with a history of abnormal 1-hour screens in a prior pregnancy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

1066 Defining cutoffs for 1-hour GCT in early diagnosis of gestational diabetes

To determine the ideal cutoff for the 1-hour 50-gram glucose challenge test performed prior to 16 weeks of gestation Single center retrospective cohort study of adult singleton pregnant women who had glucose challenge (GCT) and tolerance testing (GTT) prior to 16 weeks (early) or between 24 and 28 weeks of gestation (routine), sent to the laboratory at Weill Cornell Medicine between December 2007 and June 2017. We calculated the sensitivity, specificity and Youden Index of cutoffs between 130 mg/dL and 199 mg/dL for the early GCT and routine GCT. 20,619 women met study criteria, overall prevalence of GDM was 14.9% (7.4% early diagnosis, 17.2% routine diagnosis). Youden index estimates optimal cutoff value of 132 mg/dL for early GCT with corresponding sensitivity and specificity of 100% and 80% whereas optimal cutoff for routine GCT was 130mg/dL with corresponding sensitivity and specificity of 100% and 82%. Area under the curve for early GCT is 0.95 ± 0.0022 and for routine GCT is 0.95 ± 0.0074 (p=0.81). Both the early and routine GCT are good screening tests with optimal cutoff values of 132 mg/dL and 130mg/dL, respectively. Lower cutoffs are crucial in order to capture all cases of GDM within the population. As the ROC for the early and late GCT are similar, using a similar threshold for the early GCT is clinically justified. Further studies are needed to correlate cutoff values with clinical outcomes.

189 Predicting gestational diabetes in subsequent pregnancy using a novel risk calculator: implications for testing

The current standard is to screen all women for gestational diabetes (GDM) regardless of prior history. We assessed whether variables from an index pregnancy (PG1) in women with a normal 1-hour glucose challenge test (GCT) can be used to guide testing in subsequent pregnancy (PG2), and created a risk calculator for GDM in PG2. We studied a cohort of women who delivered 2 singleton pregnancies at >24 weeks' gestation at a single institution from June 2009-December 2018. All patients had normal GCTs in PG1 (200mg/dL, >2 elevated values on a 3-hour diagnostic test (GTT, Carpenter-Coustan criteria), or a diagnosis of GDM by ICD codes. Univariable and multivariable analyses (MVA) were performed to examine the relationship between GDM in PG2 and demographic, clinical, and laboratory variables from PG1. A risk calculator for GDM in PG2 was created using regression coefficients from the MVA. 3,719 women met inclusion criteria and 146 (3.9%) developed GDM in PG2 (Table 1). In MVA, those with GDM in PG2 were significantly more likely to be older, have higher GCTs in PG1, be of Hispanic ethnicity or Asian race, have delivered large for gestational age neonates in PG1 and have a higher BMI in PG2 (Table 2). A risk calculator for GDM in PG2 was created using race/ethnicity, PG2 age and BMI and PG1 GCT result and birthweight category. Using a risk cutoff of 20%, 3.7% of patients are identified as being "at risk" of GDM in PG2, with a positive predictive value (PPV) of 29% and a negative PV of 97%. Among patients with a normal GCT in PG1, the likelihood of a diagnosis of GDM in PG2 is only 3.9%. A calculator is presented for estimating individual risk using readily available data. Use of this calculator may permit supplanting the current practice of universal GDM screening in subsequent pregnancies with a targeted approach, limiting screening to fewer than 4% of women with normal GCTs in the index pregnancy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Objectively Measured Physical Activity During The First Trimester And Glucose Tolerance At 24-28 Weeks Gestation

Physical activity (PA) during pregnancy may improve glucose tolerance and reduce the risks of adverse outcomes associated with pregnancy hyperglycemia (e.g., pregnancy and delivery complications, delivering a large infant, and developing diabetes later in life), yet the evidence to date has primarily relied on self-reported PA via questionnaire. PURPOSE: To examine whether objectively measured PA during the first trimester of pregnancy is associated with glucose tolerance at 24-28 weeks’ gestation. METHODS: Study participants (n=261) were a subsample of the GestationaL Weight Gain and Optimal Wellness (GLOW) trial conducted at Kaiser Permanente Northern California in 2014-2016 to test whether a lifestyle intervention prevents excess gestational weight gain in women with overweight/obesity, as compared to usual medical care. Participants wore an ActiGraph wGT3X-BT for 7 days on the non-dominant wrist during the first trimester. Valid measurements were defined as having ≥ 600 minutes of wear time [by the algorithm of Choi et al. (MSSE, 2012)] on 4 days, including 1 weekend day. Wrist-specific two-regression algorithms [Hibbing et al. (MSSE, 2018)] were used to estimate daily minutes of moderate to vigorous intensity PA (MVPA), light PA (LPA), and sedentary behavior (SB). Minutes per day of MVPA, LPA, and SB were then combined into weighted (i.e., weekend day vs. weekday) averages. Plasma glucose values from a random, 50-g 1-hour glucose challenge test (GCT) performed at 24-28 weeks’ gestation were obtained from the Kaiser Permanente Northern California electronic health records. Associations of MVPA, LPA and SB (i.e., log transformed) with glucose were estimated by linear regression and adjusted for age, race-ethnicity, BMI category, and GLOW trial randomization (i.e., intervention vs. usual care). RESULTS: The cohort had a median 38 (IQR= 37) minutes per day of MVPA, 248 (81) minutes per day of LPA, and 389 (97) minutes per day of SB. The median plasma glucose value on the GCT was 112 mg/dl (35). None of the PA variables were statistically significantly associated with plasma glucose (p > .05 for MVPA, LPA, and SB). CONCLUSION: Objectively measured PA, assessed over 7 days during the first trimester of pregnancy, does not appear to impact glucose tolerance at 24-28 weeks gestation in women with overweight/obesity.

Two-day postpartum compared with 4- to 12-week postpartum glucose tolerance testing for women with gestational diabetes

A majority of women in the United States with gestational diabetes mellitus do not undergo the recommended 4- to 12-week postpartum glucose tolerance test. This study aimed to compare the diagnostic value of the 2-day postpartum glucose tolerance test with the 4- to 12-week postpartum glucose tolerance test to identify impaired glucose metabolism at 1 year after delivery among women with gestational diabetes. Postpartum women who delivered at 1 hospital between January 2017 and July 2018 were offered enrollment in a prospective cohort if they had gestational diabetes mellitus diagnosed by Carpenter-Coustan criteria or a 1-hour glucose challenge test result of ≥200 mg/dL, spoke English or Spanish, and planned to remain in the hospital for at least 2 days after delivery. Participating women underwent a 75-gram 2-hour glucose tolerance test on postpartum day 2 and were incentivized to have a 4- to 12-week glucose tolerance test and measurement of glycosylated hemoglobin at 1 year after delivery. Participants and providers were blinded to the 2-day postpartum results. The diagnostic value of an abnormal 2-day postpartum glucose tolerance test (fasting result of ≥100 mg/dL or 2-hour glucose tolerance test result of ≥140 mg/dL) was compared with that of an abnormal 4- to 12-week glucose tolerance test to identify impaired glucose metabolism (≥5.7% glycosylated hemoglobin) and diabetes (≥6.5% glycosylated hemoglobin) at 1 year after delivery. Receiver operating characteristic (ROC) curves were also compared at 2 days and 4-12 weeks after delivery. Of the 300 recruited women, 296 (99%) completed the 2-day postpartum glucose tolerance test, and 202 (68%) returned for the 4- to 12-week glucose tolerance test. Approximately 1 year after delivery, 203 (68%) women had their glycosylated hemoglobin measured, of whom 35% had impaired glucose metabolism and 4% had diabetes. The study population was diverse (46% nonwhite). Furthermore, 56% were obese (mean body mass index, 32 kg/m2), and 55% had received medication to control their glucose during pregnancy. There were no significant differences between the 2-day and 4- to 12-week postpartum glucose tolerance tests in predicting impaired glucose metabolism based on ≥5.7% glycosylated hemoglobin in 1 year after delivery: sensitivity (46% vs 36%); specificity (79% vs 84%); positive predictive value (52% vs 53%); and negative predictive value (75% vs 72%). There was also no difference between the 2-day and the 4- to 12-week glucose tolerance tests in identifying diabetes at 1 year after delivery. Both the 2-day and 4- to 12-week glucose tolerance tests had similar ROC curves in identifying impaired glucose metabolism and diabetes at 1 year after delivery. Two-day postpartum glucose tolerance tests have similar diagnostic value as 4- to 12-week postpartum glucose tolerance tests in predicting impaired glucose metabolism and diabetes at 1 year after delivery and are associated with nearly 100% adherence to the test. Thus, changing the timing of the glucose tolerance test should be considered.

Prevalence and risk factors of gestational diabetes mellitus among pregnant patients visiting National Guard primary health care centers in Saudi Arabia.

Objectives:To measure the prevalence of gestational diabetes mellitus (GDM) and its risk factors in Saudi Arabia, in comparison with developed and developing countries worldwide.Methods:We enrolled pregnant women aged 15-45 years who visited 3 National Guard-Health Affairs’ primary health care centers in Jeddah, Saudi Arabia between January 2017 and December 2017. We used stratified samples and computer-generated random numbers to collect data. This data includes demographics, obstetric history, blood pressure, non-fasting 1-hour glucose challenge test (GCT), 3-hour oral glucose tolerance test (OGTT), hemoglobin level, rubella immunization status, hepatitis B surface antigen status, urinalysis results, and labor, and delivery notes. We categorized the patients into 2 groups, GDM and non-GDM, based on GCT and OGTT.Results:We enrolled 347 women in the study (mean age, 28.8±6 years; range, 18-45 years). On GCT, 36.6% of women showed abnormal values and 6.9% exhibited diagnostic values. Oral glucose tolerance test indicated impairment in 18.7% of patients and a diagnostic finding in 15% of patients. Women diagnosed with GDM tended to be older and have greater body mass index (BMI) values.Conclusion:The prevalence of GDM in Saudi Arabia is high compared to other countries. Advanced maternal age and higher BMI values were associated with increased prevalence of GDM. Thus, early prevention and management of GDM is vital to minimize the risks to both the mother and fetus.

A Low 50-gram, 1-hour Glucose Challenge Test Value Predicts Neonatal Birth Weight Less than the 10th Percentile: A Systematic Review and Meta-Analysis.

This study aimed to perform a systematic review with meta-analysis to investigate if women with a low 50-g, 1-hour glucose challenge test (GCT) value are at risk for having neonates with a birth weight less than the 10th percentile. A computerized literature search was conducted to identify studies that compared outcomes of pregnant women with a low GCT value versus women with a normal GCT value during routine screening for gestational diabetes. Sixteen cohort studies were included for analysis. Women with a low GCT value were noted to have a 43% increased odds of having neonates with birth weight less than the 10th percentile (odds ratio [OR]: 1.43; 95% confidence interval [CI]: 1.28-1.60) and 30% increased odds of having neonates with a birth weight less than 2,500 g (OR: 1.3; 95% CI: 1.0-1.7) when compared with women with a normal GCT value. The rates of preterm delivery, neonatal intensive care unit (NICU) admission, pregnancy-induced hypertension (PIH)/preeclampsia, respiratory distress, NICU, and Apgar scores less than 7 were similar in the two groups. A low GCT value defined as less than 90 mg/dL identifies pregnancies at elevated risk for having neonates with a birth weight less than the 10th percentile.

Early gestational diabetes screening in obese women: a randomized controlled trial

Although in 2013 the American College of Obstetricians and Gynecologists recommended early screening for gestational diabetes in obese women, no studies demonstrate an improvement in perinatal outcomes with this strategy. We sought to determine whether early screening for gestational diabetes improves perinatal outcomes in obese women. Randomized controlled trial comparing early gestational diabetes screening (14-20 weeks) to routine screening (24-28 weeks) in obese women (body mass index ≥30 kg/m2) at 2 tertiary care centers in the United States. Screening was performed using a 50-g, 1-hour glucose challenge test followedby a 100-g, 3-hour glucose tolerance test if the initial screen was ≥135 mg/dL. Gestational diabetes was diagnosed usingCarpenter-Coustan criteria. Women not diagnosed at 14 to 20weeks were rescreened at 24 to 28 weeks. Exclusion criteria werepre-existing diabetes, major medical illness, bariatric surgery, andprior cesarean delivery. The primary outcome was a compositeofmacrosomia (>4000 g), primary cesarean delivery, hypertensive disease of pregnancy, shoulder dystocia, neonatal hyperbilirubinemia, and neonatal hypoglycemia (assessed within 48 hours of birth). A total of 962 women were randomized, and outcomes were available for 922. Of these 922 women, 459 (49.8%) were assigned to early screen and 463 (50.2%) to routine screen. Baseline characteristics were balanced between groups. In the early screening group, 69 (15.0%; 95% confidence interval, 11.9-18.6%) were diagnosed with gestational diabetes: 29 (6.3%; 95% confidence interval, 4.3-8.9%) at <20 weeks and 40 (8.7%; 95% confidence interval, 6.3-11.7%) at >24 weeks. Of those randomized to routine screening, 56 (12.1%; 95% confidence interval, 9.3-15.4%) had gestational diabetes. Early screening did not reduce the incidence of the primary outcome (56.9% in the early screen versus 50.8% in the routine screen, P= .07; relative risk, 1.12; 95% confidence interval, 0.99-1.26). Early screening for gestational diabetes in obese women did not reduce the composite perinatal outcome.