Cohort profile: the Environmental Reproductive and Glucose Outcomes (ERGO) Study (Boston, Massachusetts, USA) - a prospective pregnancy cohort study of the impacts of environmental exposures on parental cardiometabolic health

PURPOSE

Pregnancy and the postpartum period are increasingly recognised as sensitive windows for cardiometabolic disease risk. Growing evidence suggests environmental exposures, including endocrine-disrupting chemicals (EDCs), are associated with an increased risk of pregnancy complications that are associated with long-term cardiometabolic risk. However, the impact of perinatal EDC exposure on subsequent cardiometabolic risk post-pregnancy is less understood. The Environmental Reproductive and Glucose Outcomes (ERGO) Study was established to investigate the associations of environmental exposures during the perinatal period with post-pregnancy parental cardiometabolic health.

PARTICIPANTS

Pregnant individuals aged ≥18 years without pre-existing diabetes were recruited at <15 weeks of gestation from Boston, Massachusetts area hospitals. Participants completed ≤4 prenatal study visits (median: 12, 19, 26, 36 weeks of gestation) and 1 postpartum visit (median: 9 weeks), during which we collected biospecimens, health histories, demographic and behavioural data, and vitals and anthropometric measurements. Participants completed a postpartum fasting 2-hour 75 g oral glucose tolerance test. Clinical data were abstracted from electronic medical records. Ongoing (as of 2024) extended post-pregnancy follow-up visits occur annually following similar data collection protocols.

FINDINGS TO DATE

We enrolled 653 unique pregnancies and retained 633 through delivery. Participants had a mean age of 33 years, 10% (n=61) developed gestational diabetes and 8% (n=50) developed pre-eclampsia. Participant pregnancy and postpartum urinary phthalate metabolite concentrations and postpartum glycaemic biomarkers were quantified. To date, studies within ERGO found higher exposure to phthalates and phthalate mixtures, and separately, higher exposure to radioactive ambient particulate matter, were associated with adverse gestational glycaemic outcomes. Additionally, certain personal care products used in pregnancy, notably hair oils, were associated with higher urinary phthalate metabolite concentrations, earlier gestational age at delivery and lower birth weight.

FUTURE PLANS

Future work will leverage the longitudinal data collected on pregnancy and cardiometabolic outcomes, environmental exposures, questionnaires, banked biospecimens and paediatric data within the ERGO Study.

Metabolomic and genetic architecture of gestational diabetes subtypes

AIMS/HYPOTHESIS

Physiological gestational diabetes mellitus (GDM) subtypes that may confer different risks for adverse pregnancy outcomes have been defined. The aim of this study was to characterise the metabolome and genetic architecture of GDM subtypes to address the hypothesis that they differ between GDM subtypes.

METHODS

This was a cross-sectional study of participants in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study who underwent an OGTT at approximately 28 weeks' gestation. GDM was defined retrospectively using International Association of Diabetes and Pregnancy Study Groups/WHO criteria, and classified as insulin-deficient GDM (insulin secretion <25th percentile with preserved insulin sensitivity) or insulin-resistant GDM (insulin sensitivity <25th percentile with preserved insulin secretion). Metabolomic analyses were performed on fasting and 1 h serum samples in 3463 individuals (576 with GDM). Genome-wide genotype data were obtained for 8067 individuals (1323 with GDM).

RESULTS

Regression analyses demonstrated striking differences between the metabolomes for insulin-deficient or insulin-resistant GDM compared to those with normal glucose tolerance. After adjustment for covariates, 33 fasting metabolites, including 22 medium- and long-chain acylcarnitines, were uniquely associated with insulin-deficient GDM; 23 metabolites, including the branched-chain amino acids and their metabolites, were uniquely associated with insulin-resistant GDM; two metabolites (glycerol and 2-hydroxybutyrate) were associated with the same direction of association with both subtypes. Subtype differences were also observed 1 h after a glucose load. In genome-wide association studies, variants within MTNR1B (rs10830963, p=3.43×10-18, OR 1.55) and GCKR (rs1260326, p=5.17×10-13, OR 1.43) were associated with GDM. Variants in GCKR (rs1260326, p=1.36×10-13, OR 1.60) and MTNR1B (rs10830963, p=1.22×10-9, OR 1.49) demonstrated genome-wide significant association with insulin-resistant GDM; there were no significant associations with insulin-deficient GDM. The lead SNP in GCKR, rs1260326, was associated with the levels of eight of the 25 fasting metabolites that were associated with insulin-resistant GDM and ten of 41 1 h metabolites that were associated with insulin-resistant GDM.

CONCLUSIONS/INTERPRETATION

This study demonstrates that physiological GDM subtypes differ in their metabolome and genetic architecture. These findings require replication in additional cohorts, but suggest that these differences may contribute to subtype-related adverse pregnancy outcomes.

Placental IGFBP1 levels during early pregnancy and the risk of insulin resistance and gestational diabetes

Reduced insulin sensitivity (insulin resistance) is a hallmark of normal physiology in late pregnancy and also underlies gestational diabetes mellitus (GDM). We conducted transcriptomic profiling of 434 human placentas and identified a positive association between insulin-like growth factor binding protein 1 gene (IGFBP1) expression in the placenta and insulin sensitivity at ~26 weeks gestation. Circulating IGFBP1 protein levels rose over the course of pregnancy and declined postpartum, which, together with high gene expression levels in our placenta samples, suggests a placental or decidual source. Higher circulating IGFBP1 levels were associated with greater insulin sensitivity (lesser insulin resistance) at ~26 weeks gestation in the same cohort and in two additional pregnancy cohorts. In addition, low circulating IGFBP1 levels in early pregnancy predicted subsequent GDM diagnosis in two cohorts of pregnant women. These results implicate IGFBP1 in the glycemic physiology of pregnancy and suggest a role for placental IGFBP1 deficiency in GDM pathogenesis.

The simultaneous occurrence of gestational diabetes and hypertensive disorders of pregnancy affects fetal growth and neonatal morbidity

BACKGROUND

Gestational diabetes is associated with increased risk of hypertensive disorders of pregnancy, but there are limited data on fetal growth and neonatal outcomes when both conditions are present.

OBJECTIVE

We evaluated the risk of abnormal fetal growth and neonatal morbidity in pregnancies with co-occurrence of gestational diabetes and hypertensive disorders of pregnancy.

STUDY DESIGN

In a retrospective study of 47,093 singleton pregnancies, we compared the incidence of appropriate for gestational age birthweight in pregnancies affected by gestational diabetes alone, hypertensive disorders of pregnancy alone, or both gestational diabetes and hypertensive disorders of pregnancy with that in pregnancies affected by neither disorder using generalized estimating equations (covariates: maternal age, nulliparity, body mass index, insurance type, race, marital status, and prenatal care site). Secondary outcomes were large for gestational age birthweight, small for gestational age birthweight, and a neonatal morbidity composite outcome (stillbirth, hypoglycemia, hyperbilirubinemia, respiratory distress, encephalopathy, preterm delivery, neonatal death, and neonatal intensive care unit admission).

RESULTS

The median (interquartile range) birthweight percentile in pregnancies with both gestational diabetes and hypertensive disorders of pregnancy (50 [24.0-78.0]; N=179) was similar to that of unaffected pregnancies (50 [27.0-73.0]; N=35,833). However, the absolute rate of appropriate for gestational age birthweight was lower for gestational diabetes/hypertensive disorders of pregnancy co-occurrence (78.2% vs 84.9% for unaffected pregnancies). Adjusted analyses showed decreased odds of appropriate for gestational age birthweight in pregnancies with both gestational diabetes and hypertensive disorders of pregnancy compared with unaffected pregnancies (adjusted odds ratio, 0.72 [95% confidence interval, 0.52-1.00]; P=.049), and in pregnancies complicated by gestational diabetes alone (adjusted odds ratio, 0.78 [0.68-0.89]; P<.001) or hypertensive disorders of pregnancy alone (adjusted odds ratio, 0.73 [0.66-0.81]; P<.001). The absolute risk of large for gestational age birthweight was greater in pregnancies with both gestational diabetes and hypertensive disorders of pregnancy (14.5%) than in unaffected pregnancies (8.2%), without apparent difference in the risk of small for gestational age birthweight (7.3% vs 6.9%). However, in adjusted models comparing pregnancies with gestational diabetes/hypertensive disorders of pregnancy co-occurrence with unaffected pregnancies, neither an association with large for gestational age birthweight (adjusted odds ratio, 1.33 [0.88-2.00]; P=.171) nor small for gestational age birthweight (adjusted odds ratio, 1.32 [0.80-2.19]; P=.293) reached statistical significance. Gestational diabetes/hypertensive disorders of pregnancy co-occurrence carried an increased risk of neonatal morbidity that was greater than that observed with either condition alone (gestational diabetes/hypertensive disorders of pregnancy: adjusted odds ratio, 3.13 [2.35-4.17]; P<.001; gestational diabetes alone: adjusted odds ratio, 2.01 [1.78-2.27]; P<.001; hypertensive disorders of pregnancy alone: adjusted odds ratio, 1.38 [1.26-1.50]; P<.001).

CONCLUSION

Although pregnancies with both gestational diabetes and hypertensive disorders of pregnancy have a similar median birthweight percentile to those affected by neither condition, pregnancies concurrently affected by both conditions have a higher risk of abnormal fetal growth and neonatal morbidity.

Estimating Glycemia From HbA1c and CGM: Analysis of Accuracy and Sources of Discrepancy

OBJECTIVE

To examine the accuracy of different periods of continuous glucose monitoring (CGM), hemoglobin A1c (HbA1c), and their combination for estimating mean glycemia over 90 days (AG90).

RESEARCH DESIGN AND METHODS

We retrospectively studied 985 CGM periods of 90 days with <10% missing data from 315 adults (86% of whom had type 1 diabetes) with paired HbA1c measurements. The impact of mean red blood cell age as a proxy for nonglycemic effects on HbA1c was estimated using published theoretical models and in comparison with empirical data. Given the lack of a gold standard measurement for AG90, we applied correction methods to generate a reference (eAG90) that we used to assess accuracy for HbA1c and CGM.

RESULTS

Using 14 days of CGM at the end of the 90-day period resulted in a mean absolute error (95th percentile) of 14 (34) mg/dL when compared with eAG90. Nonglycemic effects on HbA1c led to a mean absolute error for average glucose calculated from HbA1c of 12 (29) mg/dL. Combining 14 days of CGM with HbA1c reduced the error to 10 (26) mg/dL. Mismatches between CGM and HbA1c >40 mg/dL occurred more than 5% of the time.

CONCLUSIONS

The accuracy of estimates of eAG90 from limited periods of CGM can be improved by averaging with an HbA1c-based estimate or extending the monitoring period beyond ∼26 days. Large mismatches between eAG90 estimated from CGM and HbA1c are not unusual and may persist due to stable nonglycemic factors.

Higher Maternal Body Mass Index Is Associated With Lower Placental Expression of EPYC: A Genome-Wide Transcriptomic Study

CONTEXT

Elevated body mass index (BMI) in pregnancy is associated with adverse maternal and fetal outcomes. The placental transcriptome may elucidate molecular mechanisms underlying these associations.

OBJECTIVE

We examined the association of first-trimester maternal BMI with the placental transcriptome in the Gen3G prospective cohort.

METHODS

We enrolled participants at 5 to 16 weeks of gestation and measured height and weight. We collected placenta samples at delivery. We performed whole-genome RNA sequencing using Illumina HiSeq 4000 and aligned RNA sequences based on the GTEx v8 pipeline. We conducted differential gene expression analysis of over 15 000 genes from 450 placental samples and reported the change in normalized gene expression per 1-unit increase in log2 BMI (kg/m2) as a continuous variable using Limma Voom. We adjusted models for maternal age, fetal sex, gestational age at delivery, gravidity, and surrogate variables accounting for technical variability. We compared participants with BMI of 18.5 to 24.9 mg/kg2 (N = 257) vs those with obesity (BMI ≥30 kg/m2, N = 82) in secondary analyses.

RESULTS

Participants' mean ± SD age was 28.2 ± 4.4 years and BMI was 25.4 ± 5.5 kg/m2 in early pregnancy. Higher maternal BMI was associated with lower placental expression of EPYC (slope = -1.94, false discovery rate [FDR]-adjusted P = 7.3 × 10-6 for continuous BMI; log2 fold change = -1.35, FDR-adjusted P = 3.4 × 10-3 for BMI ≥30 vs BMI 18.5-24.9 kg/m2) and with higher placental expression of IGFBP6, CHRDL1, and CXCL13 after adjustment for covariates and accounting for multiple testing (FDR < 0.05).

CONCLUSION

Our genome-wide transcriptomic study revealed novel genes potentially implicated in placental biologic response to higher maternal BMI in early pregnancy.

Glycated Albumin and Glycemia in Pregnancy and Postpartum: A Pilot Study

OBJECTIVE

 Percent glycated albumin (%GAlb) is a marker of glycemia over the past 2 to 3 weeks in nonpregnant individuals. Longitudinal changes in %GAlb extending throughout pregnancy and postpartum (PP) have not been described. We aimed to describe levels of %GAlb throughout pregnancy and PP and relationships with glycemia.

STUDY DESIGN

 Fifty women among those in the Study of Pregnancy Regulation of INsulin and Glucose cohort underwent 75-g oral glucose tolerance tests (OGTTs) at a mean of 13 weeks (V1) and 26 weeks (V2) of gestation and 11 weeks' PP. %GAlb was measured on frozen plasma samples.

RESULTS

 Total albumin decreased from V1 to V2 and increased PP to levels higher than at V1. %GAlb declined between V1 and V2 (β = - 0.63% 95% CI [-0.8, -0.6] p < 0.001) and remained stable between V2 and PP (β = - 0.04% [-0.3, 0.2] p = 0.78). Body mass index (BMI) was inversely related to %GAlb in pregnancy (V1: rho = - 0.5, p = 0.0001; V2 rho = - 0.4, p = 0.006), but not PP (rho = - 0.15, p = 0.31). The longitudinal changes in %GAlb persisted after adjusting for BMI. Neither glycemia measurements nor hemoglobin A1c were associated with %GAlb at any time point, and adjustments for BMI did not reveal additional associations.

CONCLUSION

 %GAlb decreases between early and late gestation and remains decreased PP, despite a PP increase in total albumin above early pregnancy values. Given the lack of correlation with OGTT values or A1c, %GAlb is unlikely to be useful in assessing glycemia in pregnant or PP women.

KEY POINTS

· Changes in %GAlb extending to the postpartum period have not been described.. · %GAlb decreases in pregnancy and remains decreased postpartum, despite a postpartum increase in total albumin above early pregnancy values.. · Glycemia measurements nor A1c were associated with %GAlb at any time point, therefore, %GAlb is unlikely to be useful in assessing glycemia in pregnant or postpartum women..

Refining the diagnosis of gestational diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

Perinatal outcomes vary for women with gestational diabetes mellitus (GDM). The precise factors beyond glycemic status that may refine GDM diagnosis remain unclear. We conducted a systematic review and meta-analysis of potential precision markers for GDM.

METHODS

Systematic literature searches were performed in PubMed and EMBASE from inception to March 2022 for studies comparing perinatal outcomes among women with GDM. We searched for precision markers in the following categories: maternal anthropometrics, clinical/sociocultural factors, non-glycemic biochemical markers, genetics/genomics or other -omics, and fetal biometry. We conducted post-hoc meta-analyses of a subset of studies with data on the association of maternal body mass index (BMI, kg/m2) with offspring macrosomia or large-for-gestational age (LGA).

RESULTS

A total of 5905 titles/abstracts were screened, 775 full-texts reviewed, and 137 studies synthesized. Maternal anthropometrics were the most frequent risk marker. Meta-analysis demonstrated that women with GDM and overweight/obesity vs. GDM with normal range BMI are at higher risk of offspring macrosomia (13 studies [n = 28,763]; odds ratio [OR] 2.65; 95% Confidence Interval [CI] 1.91, 3.68), and LGA (10 studies [n = 20,070]; OR 2.23; 95% CI 2.00, 2.49). Lipids and insulin resistance/secretion indices were the most studied non-glycemic biochemical markers, with increased triglycerides and insulin resistance generally associated with greater risk of offspring macrosomia or LGA. Studies evaluating other markers had inconsistent findings as to whether they could be used as precision markers.

CONCLUSIONS

Maternal overweight/obesity is associated with greater risk of offspring macrosomia or LGA in women with GDM. Pregnancy insulin resistance or hypertriglyceridemia may be useful in GDM risk stratification. Future studies examining non-glycemic biochemical, genetic, other -omic, or sociocultural precision markers among women with GDM are warranted.

A long-acting prolactin to combat lactation insufficiency

Human infants are born to breastfeed. While 50% of lactating persons struggle to make enough milk, there are no governmentally-approved drugs to enhance lactation1. Here, we engineer a variant of the naturally-occurring driver of lactation, the hormone Prolactin, to increase its serum half-life and produce a viable drug candidate. Our engineered variant, Prolactin-eXtra Long-acting (Prolactin-XL), is comprised of endogenously active human prolactin fused to an engineered human IgG Fc domain designed to overcome the unique drug development challenges specific to the lactating person-infant dyad. Our Prolactin-XL has a serum half-life of 70.9h in mice, 2,625-fold longer than endogenously active prolactin alone (70.9h v. 0.027h). We demonstrate that Prolactin-XL increases milk production and restores growth of pups fed by dams with pharmacologically-ablated lactation. We show that Prolactin-XL-enhanced lactation is accompanied by reversible, lactocyte-driven changes in mammary gland morphology. This work establishes long-acting prolactins as a potentially powerful pharmacologic means to combat insufficient lactation.

Patient Priorities, Decisional Comfort, and Satisfaction with Metformin versus Insulin for the Treatment of Gestational Diabetes Mellitus

OBJECTIVE

 We compared patient priorities, decisional comfort, and satisfaction with treating gestational diabetes mellitus (GDM) with metformin versus insulin among pregnant individuals with GDM requiring pharmacotherapy.

STUDY DESIGN

 We conducted a cross-sectional study of patients' perspectives about GDM pharmacotherapy in an integrated prenatal and diabetes care program from October 19, 2022, to August 24, 2023. The exposure was metformin versus insulin as the initial medication decision. Outcomes included standardized measures of patient priorities, decisional comfort, and satisfaction about their medication decision.

RESULTS

 Among 144 assessed individuals, 60.4% were prescribed metformin and 39.6% were prescribed insulin. Minoritized individuals were more likely to receive metformin compared with non-Hispanic White individuals (34.9 vs. 17.5%; p = 0.03). Individuals who were willing to participate in a GDM pharmacotherapy clinical trial were more likely to receive insulin than those who were unwilling (30.4 vs. 19.5%; p = 0.02). Individuals receiving metformin were more likely to report prioritizing avoiding injections (62.4 vs. 19.3%; adjusted odds ratio [aOR]: 2.83; 95% confidence interval [CI]: 1.10-7.31), wanting to take a medication no more than twice daily (56.0 vs. 30.4%; aOR: 3.67; 95% CI: 1.56-8.67), and believing that both medications can equally prevent adverse pregnancy outcomes (70.9 vs. 52.6%; aOR: 2.67; 95% CI: 1.19-6.03). Conversely, they were less likely to report prioritizing a medication that crosses the placenta (39.1 vs. 82.5%; aOR: 0.09; 95% CI: 0.03-0.25) and needing supplemental insulin to achieve glycemic control (21.2 vs. 47.4%; aOR: 0.36; 95% CI: 0.15-0.90). Individuals reported similarly high (mean score > 80%) levels of decisional comfort, personal satisfaction with medication decision-making, and satisfaction about their conversation with their provider about their medication decision with metformin and insulin (p ≥ 0.05 for all).

CONCLUSION

 Individuals with GDM requiring pharmacotherapy reported high levels of decision comfort and satisfaction with both metformin and insulin, although they expressed different priorities in medication decision-making. These results can inform future patient-centered GDM treatment strategies.

KEY POINTS

· Pregnant individuals with GDM requiring pharmacotherapy expressed a high level of decisional comfort and satisfaction with medication decision making.. · Individuals placed different priorities on deciding to take metformin versus insulin.. · These results can inform interventions aimed at delivering person-centered diabetes care in pregnancy that integrates patient autonomy and knowledge about treatment options..

Distinct Insulin Physiology Trajectories in Euglycemic Pregnancy and Gestational Diabetes Mellitus

OBJECTIVE

To evaluate changes in insulin physiology in euglycemic pregnancy and gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

Participants underwent oral glucose tolerance tests at ≤15 weeks' gestation (early pregnancy), 24-32 weeks' gestation (mid-late pregnancy), and 6-24 weeks postpartum. We evaluated longitudinal changes in insulin secretory response (log Stumvoll first-phase estimate) and insulin sensitivity (log Matsuda index) using linear mixed models. We then evaluated participants who met GDM criteria in early pregnancy (early GDM) and mid-late pregnancy (classic GDM) separately from those without GDM. We derived the pregnancy insulin physiology (PIP) index to quantify β-cell compensation for insulin resistance.

RESULTS

Among 166 participants, 21 had early GDM and 24 developed classic GDM. Insulin sensitivity was reduced slightly in early pregnancy (β = -0.20, P < 0.001) and substantially in mid-late pregnancy (β = -0.47, P < 0.001) compared with postpartum. Insulin secretory response (adjusted for insulin sensitivity) was augmented in early pregnancy (β = 0.16, P < 0.001) and mid-late pregnancy (β = 0.16, P = 0.001) compared with postpartum. Compared with postpartum, the PIP index was augmented in early pregnancy (β = 215, P = 0.04) but not mid-late pregnancy (β = 55, P = 0.64). Early GDM was distinguished by a substantial reduction in early pregnancy insulin sensitivity (β = -0.59, P < 0.001) compared with postpartum. Both early and classic GDM lacked evidence of early pregnancy augmentation of insulin secretory response (adjusted for insulin sensitivity) and the PIP index (P > 0.1 vs. postpartum). Early pregnancy PIP index predicted GDM independent of participant characteristics (area under the curve without PIP index 0.70 [95% CI 0.61-0.79], area under the curve with PIP index 0.87 [95% CI 0.80-0.93]).

CONCLUSIONS

β-Cell function is enhanced in early pregnancy. Deficient first-trimester β-cell function predicts GDM.

Supporting Our Physician Parents (SOPPort): A pilot program for parental wellness at the Massachusetts General Hospital

Physician parents encounter unique challenges in balancing new parenthood with work responsibilities, especially upon their return from parental leave. We designed a pilot program that incorporated 1:1 parental coaching to expectant and new physician parents and provided stipends for lactation support and help at home. Additional initiatives included launching a virtual new parent group during the COVID-19 pandemic and starting an emergency backup pump supplies program. There was positive feedback for our Parental Wellness Program (PWP), which was used to secure expanded funding. Pilot results showed that our program had a meaningful impact on parental wellness, morale, productivity, and lactation efforts.

Second international consensus report on gaps and opportunities for the clinical translation of precision diabetes medicine

Precision medicine is part of the logical evolution of contemporary evidence-based medicine that seeks to reduce errors and optimize outcomes when making medical decisions and health recommendations. Diabetes affects hundreds of millions of people worldwide, many of whom will develop life-threatening complications and die prematurely. Precision medicine can potentially address this enormous problem by accounting for heterogeneity in the etiology, clinical presentation and pathogenesis of common forms of diabetes and risks of complications. This second international consensus report on precision diabetes medicine summarizes the findings from a systematic evidence review across the key pillars of precision medicine (prevention, diagnosis, treatment, prognosis) in four recognized forms of diabetes (monogenic, gestational, type 1, type 2). These reviews address key questions about the translation of precision medicine research into practice. Although not complete, owing to the vast literature on this topic, they revealed opportunities for the immediate or near-term clinical implementation of precision diabetes medicine; furthermore, we expose important gaps in knowledge, focusing on the need to obtain new clinically relevant evidence. Gaps include the need for common standards for clinical readiness, including consideration of cost-effectiveness, health equity, predictive accuracy, liability and accessibility. Key milestones are outlined for the broad clinical implementation of precision diabetes medicine.

Carbohydrate Intake and Oral Glucose Tolerance Test Results in the Postpartum Period

CONTEXT

The American Diabetes Association (ADA) recommends a 3-day preparatory diet prior to a diagnostic oral glucose tolerance test (OGTT), a test often recommended in postpartum individuals with a history of gestational diabetes (GDM).

OBJECTIVE

Evaluate the relationship between carbohydrate intake and OGTT glucose in 2 cohorts of postpartum individuals.

METHODS

We performed analyses of postpartum individuals from 2 prospective studies with recent GDM (Balance after Baby Intervention, BABI, n = 177) or risk factors for GDM (Study of Pregnancy Regulation of INsulin and Glucose, SPRING, n = 104) .We measured carbohydrate intake using 24-hour dietary recalls (SPRING) or Food Frequency Questionnaire (BABI) and performed 2-hour 75-g OGTTs. The main outcome measure was 120-minute post-OGTT glucose.

RESULTS

There was no relationship between carbohydrate intake and 120-minute post-OGTT glucose level in either study population (SPRING: β = 0.03, [-5.5, 5.5] mg/dL, P = .99; BABI: β = -3.1, [-9.5, 3.4] mg/dL, P = .35). Adding breastfeeding status to the model did not change results (SPRING β = -0.14, [-5.7, 5.5] mg/dL, P = .95; BABI β = -3.9, [-10.4, 2.7] mg/dL, P = .25). There was, however, an inverse relationship between glycemic index and 120-minute post OGTT glucose (BABI: β = -1.1, [-2.2, -0.03] mg/dL, P = .04).

CONCLUSION

Carbohydrate intake is not associated with post-OGTT glucose levels among postpartum individuals. Dietary preparation prior to the OGTT may not be necessary in this population.

Sex-specific impact of maternal obesity on fetal placental macrophages and cord blood triglycerides

INTRODUCTION

Maternal obesity is associated with increased risk of offspring obesity and cardiometabolic disease. Altered fetoplacental immune programming is a potential candidate mechanism. Differences in fetal placental macrophages, or Hofbauer cells (HBCs), have been observed in maternal obesity, and lipid metabolism is a key function of resident macrophages that may be deranged in inflammation/immune activation. We sought to test the following hypotheses: 1) maternal obesity is associated with altered HBC density and phenotype in the term placenta and 2) obesity-associated HBC changes are associated with altered placental lipid transport to the fetus. The impact of fetal sex was evaluated in all experiments.

METHODS

We quantified the density and morphology of CD163-and CD68-positive HBCs in placental villi in 34 full-term pregnancies undergoing cesarean delivery (N = 15, maternal BMI ≥30 kg/m2; N = 19, BMI <30 kg/m2). Antibody-positive cells in terminal villi were detected and cell size and circularity analyzed using a semi-automated method for thresholding of bright-field microscopy images (ImageJ). Placental expression of lipid transporter genes was quantified using RTqPCR, and cord plasma triglycerides (TGs) were profiled using modified Wahlefeld method. The impact of maternal obesity and fetal sex on HBC features, lipid transporters, and cord TGs were evaluated by two-way ANOVA. Spearman correlations of cord TGs, HBC metrics and gene expression levels were calculated.

RESULTS

Maternal obesity was associated with significantly increased density of HBCs, with male placentas most affected (fetal sex by maternal obesity interaction p = 0.04). CD163+ HBCs were larger and rounder in obesity-exposed male placentas. Sexually dimorphic expression of placental FATP4, FATP6, FABPPM, AMPKB1 and AMPKG and cord TGs was noted in maternal obesity, such that levels were higher in males and lower in females relative to sex-matched controls. Cord TGs were positively correlated with HBC density and FATP1 expression.

DISCUSSION

Maternal obesity is associated with sex-specific alterations in HBC density and placental lipid transporter expression, which may impact umbilical cord blood TG levels and offspring cardiometabolic programming.

Gestational Diabetes and Long-Term Cardiometabolic Health

This JAMA Insights discusses adverse long-term effects of gestational diabetes on the pregnant individual and the exposed fetus.

Gestational Glucose Intolerance and Birth Weight-Related Complications

OBJECTIVE

To evaluate the risks of large-for-gestational-age birth weight (LGA) and birth weight-related complications in pregnant individuals with gestational glucose intolerance, an abnormal screening glucose loading test result without meeting gestational diabetes mellitus (GDM) criteria.

METHODS

In a retrospective cohort study of 46,989 individuals with singleton pregnancies who delivered after 28 weeks of gestation, those with glucose loading test results less than 140 mg/dL were classified as having normal glucose tolerance. Those with glucose loading test results of 140 mg/dL or higher and fewer than two abnormal values on a 3-hour 100-g oral glucose tolerance test (OGTT) were classified as having gestational glucose intolerance. Those with two or more abnormal OGTT values were classified as having GDM. We hypothesized that gestational glucose intolerance would be associated with higher odds of LGA (birth weight greater than the 90th percentile for gestational age and sex). We used generalized estimating equations to examine the odds of LGA in pregnant individuals with gestational glucose intolerance compared with those with normal glucose tolerance, after adjustment for age, body mass index, parity, health insurance, race and ethnicity, and marital status. In addition, we investigated differences in birth weight-related adverse pregnancy outcomes.

RESULTS

Large for gestational age was present in 7.8% of 39,685 pregnant individuals with normal glucose tolerance, 9.5% of 4,155 pregnant individuals with gestational glucose intolerance and normal OGTT, 14.5% of 1,438 pregnant individuals with gestational glucose intolerance and one abnormal OGTT value, and 16.0% of 1,711 pregnant individuals with GDM. The adjusted odds of LGA were higher in pregnant individuals with gestational glucose intolerance than in those with normal glucose tolerance overall (adjusted odds ratio [aOR] 1.35, 95% CI 1.23-1.49, P <.001). When compared separately with pregnant individuals with normal glucose tolerance, those with either gestational glucose intolerance subtype had higher adjusted LGA odds (gestational glucose intolerance with normal OGTT aOR 1.21, 95% CI 1.08-1.35, P <.001; gestational glucose intolerance with one abnormal OGTT value aOR 1.77, 95% CI 1.52-2.08, P <.001). The odds of birth weight-related adverse outcomes (including cesarean delivery, severe perineal lacerations, and shoulder dystocia or clavicular fracture) were higher in pregnant individuals with gestational glucose intolerance with one abnormal OGTT value than in those with normal glucose tolerance.

CONCLUSION

Gestational glucose intolerance in pregnancy is associated with birth weight-related adverse pregnancy outcomes. Glucose lowering should be investigated as a strategy for lowering the risk of these outcomes in this group.

Disparities in Continuous Glucose Monitoring Use Among Women of Reproductive Age with Type 1 Diabetes in the T1D Exchange

We identified characteristics associated with continuous glucose monitoring (CGM) use in women of reproductive age with type 1 diabetes (T1D) in the T1D Exchange clinic registry from 2015 to 2018. Among 6643 assessed women, the frequency of CGM increased from 2015 to 2018 (20.6% vs. 30.0%; adjusted odds ratios [aOR]: 1.72; confidence interval [95% CI]: 1.51-1.95) and was more likely with recent pregnancy (45.3% vs. 25.8%; aOR: 1.63; 95% CI: 1.23-2.16). Non-Hispanic Black and Hispanic race and ethnicity, younger age, lower educational attainment, lower income, and Medicaid insurance were associated with lower odds of CGM. The use of CGM was associated with lower odds of diabetic ketoacidosis and lower hemoglobin A1c without any difference in the odds of symptomatic severe hypoglycemia. In conclusion, although CGM use was associated with better glycemic control, the majority of reproductive-age women still did not use it. Those who did not use CGM were more likely to be those at greatest risk of adverse pregnancy outcomes.

Abstract P244: Gestational Glucose Intolerance is Associated With Hypertensive Disorders of Pregnancy in a Large Hospital-Based Multiethnic Cohort

Introduction: Hypertensive disorders of pregnancy (HDP) are associated with higher future cardiovascular risk. Treatment of gestational diabetes (GDM) has been shown to reduce the risk of HDP. It is unknown if women with gestational glucose intolerance (GGI), defined as abnormal GDM screening but without a GDM diagnosis, are at higher risk of HDP. Currently, GGI is not treated.

Hypothesis: We tested the hypothesis that GGI pregnancies have increased odds of HDP.

Methods: This is a retrospective cohort study of 41,706 singleton pregnancies delivered at an academic center. Based on the results of GDM screening and diagnostic tests, pregnancies were categorized as normal glucose tolerance (NGT, glucose loading test < 140 mg/dl), GGI (glucose loading test ≥140 mg/dl with 0 or 1 abnormal value on oral glucose tolerance testing [OGTT] thus without GDM), or GDM (≥ 2 abnormal values on OGTT). GGI was further classified into groups with zero (GGI-0) or 1 (GGI-1) abnormal OGTT values. We used laboratory, blood pressure, and delivery reports to capture HDP and exclude chronic hypertension. Generalized estimating equations for logistic regression were used to measure the risk of HDP after adjustment for age, 1st trimester BMI, parity, insurance, race/ethnicity, and marital status. A similar approach was used to test for associations between GGI and pre-eclampsia (PE).

Results: A total of 84.5% of pregnancies were classified as NGT, 8.9% as GGI-0, 3.0% as GGI-1 and 3.6% as GDM. The unadjusted frequencies of HDP and PE were higher in GGI-1 (140 [11.2%] and 64 [5.1%] of 1,251) and GDM (165 [11.1%] and 94 [6.3%] of 1,485) compared to NGT (2,275 [6.5%] and 1,100 [3.1%] of 35,238) and GGI-0 (283 [7.6%] and 136 [3.6%] of 3,732). We observed greater odds of HDP in all 3 groups compared to NGT in adjusted models, and similar trends for PE (Figure 1).

Conclusions: The risks of HDP and PE in GGI-1 are greater than for NGT pregnancies and similar to the risks in GDM. Our results suggest that women with GGI-1 should be considered for intervention, similar to GDM.

Assessment of the Validity of Administrative Data for Gestational Diabetes Ascertainment

BACKGROUND

Administrative data, including International Classification of Diseases codes and birth certificate records, are often used for retrospective gestational diabetes research investigations to describe associations of gestational diabetes with perinatal complications and long-term outcomes, and to determine gestational diabetes prevalence. Research investigating the validity of using International Classification of Diseases codes and birth certificates for gestational diabetes ascertainment shows varying degrees of reliability.

OBJECTIVE

This study aimed to evaluate the accuracy of both International Classification of Diseases codes and birth certificate diagnosis for gestational diabetes ascertainment in a large hospital-based cohort of pregnant individuals, using laboratory criteria for gestational diabetes mellitus as the reference.

STUDY DESIGN

We studied individuals who received prenatal care at an academic hospital and affiliated community health centers between 1998 and 2016. In the setting of universal 2-step screening for gestational diabetes, pregnant individuals were classified as having gestational diabetes if ≥2 oral glucose tolerance test values met or exceeded National Diabetes Data Group thresholds. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value for International Classification of Diseases code and birth certificate ascertainment of gestational diabetes, and their exact binomial 95% confidence intervals.

RESULTS

In a cohort of 51,059 pregnancies with complete glucose screening, 1303 (2.6%) met National Diabetes Data Group laboratory criteria for gestational diabetes. Gestational diabetes International Classification of Diseases codes had moderate sensitivity of 70.5% (95% confidence interval, 67.9-72.9), high specificity of 99.3% (95% confidence interval, 99.3-99.4), a positive predictive value of 73.3% (95% confidence interval, 70.8-75.8), and a negative predictive value of 99.2% (95% confidence interval, 99.1-99.3). In the 46,512 pregnancies linked to birth certificate data, birth certificate diagnosis had moderate sensitivity (66.3% [95% confidence interval, 63.6-69.0]), high specificity (98.9% [95% confidence interval, 98.8-99.0]), moderate positive predictive value (62.1% [95% confidence interval, 59.8-64.4]), and high negative predictive value (99.1% [95% confidence interval, 99.0-99.2]).

CONCLUSION

Ascertainment of gestational diabetes using administrative data, including International Classification of Diseases codes or birth certificates, has moderate sensitivity, moderate positive predictive value, high specificity, and high negative predictive value. Our findings provide context for interpreting the validity of studies that depend on administrative data for ascertainment of gestational diabetes and comparing them with prospective studies that use laboratory-based gestational diabetes criteria.

Pregnancy- and birth-related risk factors for the development of childhood celiac disease

AIM

To evaluate whether pregnancy and birth-related factors are associated with celiac disease (CD) in a large, United States (US)-based mother-child cohort.

METHODS

We analysed data gathering from the Massachusetts General Hospital Maternal Child Cohort (MMCC) of children born between 1998 and 2016. Data included the mode of delivery, maternal pregnancy and their offspring characteristics. We searched for CD cases by using diagnosis billing codes. Cox proportional hazard regression models were created to identify variables associated with CD.

RESULTS

We identified 44 539 mother-child pairs who had at least one encounter by 5 years old and identified 173 children (0.4%) with CD diagnosis; median age at the diagnosis was 6 years. Overall, the adjusted hazard ratio (aHR) of caesarean delivery for CD was 1.39 (95% CI: 0.99, 1.96, p = 0.06) when compared to children born vaginally. After stratifying for the presence of labour, children born by Caesarean delivery without labour had a higher risk of CD (aHR 1.56; 95%CI: 1.01, 2.41; p = 0.046) while infants born by Caesarean delivery with labour did not (aHR 1.26; 95% CI: 0.83, 1.93; p = 0.28).

CONCLUSION

Being born by Caesarean delivery without labour may be associated with an increased risk for CD in the US children.

Gestational Glucose Intolerance and Risk of Future Diabetes

OBJECTIVE

Pregnant individuals are universally screened for gestational diabetes mellitus (GDM). Gestational glucose intolerance (GGI) (an abnormal initial GDM screening test without a GDM diagnosis) is not a recognized diabetes risk factor. We tested for an association between GGI and diabetes after pregnancy.

RESEARCH DESIGN AND METHODS

We conducted a retrospective cohort study of individuals followed for prenatal and primary care. We defined GGI as an abnormal screening glucose-loading test result at ≥24 weeks' gestation with an oral glucose tolerance test (OGTT) that did not meet GDM criteria. The primary outcome was incident diabetes. We used Cox proportional hazards models with time-varying exposures and covariates to compare incident diabetes risk in individuals with GGI and normal glucose tolerance.

RESULTS

Among 16,836 individuals, there were 20,359 pregnancies with normal glucose tolerance, 2,943 with GGI, and 909 with GDM. Over a median of 8.4 years of follow-up, 428 individuals developed diabetes. Individuals with GGI had increased diabetes risk compared to those with normal glucose tolerance in pregnancy (adjusted hazard ratio [aHR] 2.01 [95% CI 1.54-2.62], P < 0.001). Diabetes risk increased with the number of abnormal OGTT values (zero, aHR 1.54 [1.09-2.16], P = 0.01; one, aHR 2.97 [2.07-4.27], P < 0.001; GDM, aHR 8.26 [6.49-10.51], P < 0.001 for each compared with normal glucose tolerance). The fraction of cases of diabetes 10 years after delivery attributable to GGI and GDM was 8.5% and 28.1%, respectively.

CONCLUSIONS

GGI confers an increased risk of future diabetes. Routinely available clinical data identify an unrecognized group who may benefit from enhanced diabetes screening and prevention.

First Trimester Cardiac Biomarkers among Women with Peripartum Cardiomyopathy: Are There Early Clues to This Late-Pregnancy Phenomenon?

OBJECTIVE

Whether biomarkers may enable early identification of women who develop peripartum cardiomyopathy (PPCM) prior to disease onset remains a question of interest.

STUDY DESIGN

A retrospective nested case-control study was conducted to determine whether first trimester N-terminal pro-B type natriuretic peptide (NT-proBNP) or high sensitivity cardiac troponin I (hs-cTnI) differed among women who developed PPCM versus unaffected pregnancies. Cases were matched to unaffected women by age, race, parity, and gestational age of sample (control A) and then further by blood pressure and pregnancy weight gain (control B).

RESULTS

First trimester NT-proBNP concentrations were numerically higher among women who subsequently developed PPCM (116 pg/mL [83-177]) as compared with women in control A (56.1 pg/mL [38.7-118.7], p = 0.3) or control B (37.6 [23.3 - 53.8], p <0.05). A higher proportion of women who subsequently developed PPCM (50%) had detectable levels of hs-cTnI as compared with control A (0%, p = 0.03) or control B (18.8%, p = 0.52). Among both cases and controls, hs-cTnI values were low and often below the limit of detection.

CONCLUSION

There were differences in first trimester NT-proBNP and hs-cTnI concentrations between women who subsequently developed PPCM and those who did not, raising the possibility the early pregnancy subclinical myocardial dysfunction may be associated with this late-pregnancy disease.

KEY POINTS

· First trimester NT-proBNP is numerically higher among women who subsequently develop PPCM.. · First trimester hs-cTnI was nominally higher among women who developed PPCM versus those who did not.. · A significant proportion of normal pregnant women have undetectable hs-cTnI..

Trends in gestational diabetes mellitus among nulliparous pregnant individuals with singleton live births in the United States between 2011 to 2019: an age-period-cohort analysis

BACKGROUND

The rate of gestational diabetes mellitus has increased over the past decade. An age, period, and cohort epidemiologic analysis can be used to understand how and why disease trends have changed over time.

OBJECTIVE

This study aimed to estimate the associations of age (at delivery), period (delivery year), and cohort (birth year) of the pregnant individual with trends in the incidence of gestational diabetes mellitus in the United States.

STUDY DESIGN

We conducted an age, period, and cohort analysis of nulliparous pregnant adults aged 18 to 44 years with singleton live births from the National Vital Statistics System from 2011 to 2019. Generalized linear mixed models were used to calculate the adjusted rate ratios for the incidence of gestational diabetes mellitus for each 3-year maternal age span, period, and cohort group compared with the reference group for each. We repeated the analyses with stratification according to self-reported racial and ethnic group (non-Hispanic Asian-Pacific Islander, non-Hispanic Black, Hispanic, and non-Hispanic White) because of differences in the incidence of and risk factors for gestational diabetes mellitus by race and ethnicity.

RESULTS

Among 11,897,766 pregnant individuals, 5.2% had gestational diabetes mellitus. The incidence of gestational diabetes mellitus was higher with increasing 3-year maternal age span, among those in the more recent delivery period, and among the younger birth cohort. For example, individuals aged 42 to 44 years at delivery had a 5-fold higher risk for gestational diabetes mellitus than those aged 18 to 20 years (adjusted rate ratio, 5.57; 95% confidence interval, 5.43-5.72) after adjusting for cohort and period. Individuals who delivered between 2017 and 2019 were at higher risk for gestational diabetes mellitus than those who delivered between 2011 and 2013 (adjusted rate ratio, 1.24; 95% confidence interval, 1.23-1.25) after adjusting for age and cohort. Individuals born between 1999 and 2001 had a 3-fold higher risk for gestational diabetes mellitus than those born between 1969 and 1971 (adjusted rate ratio, 3.12; 95% confidence interval, 2.87-3.39) after adjusting for age and period. Similar age, period, and cohort effects were observed for the assessed racial and ethnic groups, with the greatest period effects observed among Asian and Pacific Islander individuals.

CONCLUSION

Period and birth cohort effects have contributed to the rising incidence of gestational diabetes mellitus in the United States from 2011 to 2019.

Gestational diabetes and other adverse pregnancy outcomes in polycystic ovary syndrome

PURPOSE OF REVIEW

This review provides an update on gestational diabetes (GDM) and other adverse pregnancy outcomes in individuals with polycystic ovary syndrome (PCOS), one of the most common metabolic disorders and causes of infertility.

RECENT FINDINGS

Recent studies using Rotterdam diagnostic criteria for PCOS have supported prior literature suggesting that pregnant individuals with PCOS are at an increased risk of GDM. Risk factors for GDM in this population include overweight/obesity, insulin resistance, hyperandrogenism, amenorrhea, and history of miscarriage. It is possible that subtypes of PCOS (metabolic vs. lean/reproductive) pose differential risk. There are no current screening or treatment guidelines specifically for individuals with PCOS for GDM prevention. Although metformin has been studied for GDM prevention in PCOS, there has been no proven benefit. For infertility treatment, assisted reproductive technology and in-vitro fertilization do not appear to increase the risk of GDM in individuals with PCOS desiring pregnancy.

SUMMARY

Recent studies of pregnant individuals with PCOS suggest an increased risk of adverse pregnancy outcomes, including GDM. Larger, prospective studies using standardized diagnostic criteria are warranted to determine if the risk is from PCOS generally, or if there are subtypes of PCOS (metabolic vs. lean/reproductive) at a higher risk of GDM than others.

Association of Perceived Role Misidentification With Use of Role Identity Badges Among Resident Physicians

IMPORTANCE

Role misidentification of resident physicians occurs frequently and is associated with decreased well-being.

OBJECTIVE

To evaluate the role misidentification and burnout rates among resident physicians after disbursement of role identity badges.

DESIGN, SETTING, AND PARTICIPANTS

This quality improvement study was conducted during the 2018 to 2019 academic year. Residents in 13 surgical and nonsurgical residency programs at 2 large academic medical centers (Massachusetts General Hospital and Brigham and Women's Hospital) were eligible to receive the intervention and complete 2 surveys (before and after the intervention). Data were analyzed from December 4, 2021, to February 7, 2022.

INTERVENTION

Role identity badges that displayed "Doctor" and could be attached to mandatory hospital identification badges were distributed to residents in August 2018 at Massachusetts General Hospital and in March 2019 at Brigham and Women's Hospital. Residents were not required to wear the badge.

MAIN OUTCOMES AND MEASURES

The primary outcome was self-reported role misidentification at least once per week during the previous 3 months. The change from pre- to post-badge distribution surveys was assessed with McNemar's test. A secondary outcome was any reduction in the frequency of role misidentification after badge distribution. Multivariable logistic regression was used to assess the association between reduced frequency of role misidentification and demographic characteristics. A separate analysis evaluated the change in self-reported burnout after badge distribution.

RESULTS

A total of 161 residents (39%) completed both surveys, which included 79 men (49%), 72 (45%) who were younger than 30 years, 20 (12%) with an underrepresented in medicine status, and 74 (46%) who were in surgical specialties. The proportion of residents reporting at least weekly role misidentification decreased from 50% (n = 81 of 161) before badge distribution to 35% (n = 57 of 161; P < .001) after badge distribution. Female residents were more likely to report reduced role misidentification frequency after receiving a badge compared with male residents (adjusted odds ratio, 2.32; 95% CI, 1.18-4.63; P = .01). Residents who wore badges demonstrated no change in burnout before vs after badge distribution (39% [n = 33 of 85] vs 34% [29 of 85]; P = .87) compared with an increase among residents who did not wear a badge (27% [n = 15 of 55] vs 45% [n = 25 of 55]; P = .03).

CONCLUSIONS AND RELEVANCE

This study found that the distribution of role identity badges was associated with less frequent perception of role misidentification among resident physicians across specialties, particularly among female residents. Role identity badges were a well-received, low-cost intervention that could be used to reduce role misidentification and address burnout among residents.

Oral Glucose Tolerance Test-based Measures of Insulin Secretory Response in Pregnancy

BACKGROUND

Oral glucose tolerance test (OGTT)-based measures of insulin secretory response have not been validated in pregnancy.

METHODS

In a secondary analysis of a longitudinal study, participants were studied prepregnancy (n = 40), in early pregnancy (n = 36; 12-14 weeks' gestation), and in late pregnancy (n = 36; 34-36 weeks' gestation). Participants underwent an OGTT, an intravenous glucose tolerance test (IVGTT), and a hyperinsulinemic-euglycemic clamp at each timepoint. We calculated homeostatic model assessment of beta-cell function (HOMA-2B), insulinogenic index (IGI), corrected insulin response (CIR), ratio of the area under the insulin curve and the area under the glucose curve (AUCins/AUCglu), and Stumvoll first-phase estimate (Stumvoll) from OGTT insulin and glucose levels. We used Pearson correlation to compare measures from OGTT and IVGTT. We used mixed effects models to examine longitudinal changes in insulin secretory response.

RESULTS

Stumvoll was the only OGTT-based measure that was significantly correlated with first-phase insulin response prior to and across gestation (prepregnancy: r = 0.44, P = 0.01; early pregnancy: r = 0.67, P = 0.0001; late pregnancy: r = 0.67, P = 0.0001). In early and late pregnancy, AUCins/AUCglu had the strongest correlation with first-phase insulin response (early pregnancy: r = 0.79, P < 0.0001; late pregnancy: r = 0.69, P < 0.0001) but was not significantly correlated prepregnancy. IGI and CIR were significantly correlated with first-phase insulin response prepregnancy (IGI: r = 0.50, P = 0.005; CIR r = 0.47, P = 0.008) and in late pregnancy (IGI: r = 0.68, P = 0.0001; CIR r = 0.57, P = 0.002) but not in early pregnancy. HOMA-2B was the weakest correlate of first-phase insulin response. Stumvoll and AUCins/AUCglu recapitulated the longitudinal changes in insulin secretory response observed by IVGTT.

CONCLUSIONS

Stumvoll and AUCins/AUCglu are valid OGTT-based insulin secretory response measures for pregnancy studies.

Eradicating Racism: An Endocrine Society Policy Perspective

The Endocrine Society recognizes racism as a root cause of the health disparities that affect racial/ethnic minority communities in the United States and throughout the world. In this policy perspective, we review the sources and impact of racism on endocrine health disparities and propose interventions aimed at promoting an equitable, diverse, and just healthcare system. Racism in the healthcare system perpetuates health disparities through unequal access and quality of health services, inadequate representation of health professionals from racial/ethnic minority groups, and the propagation of the erroneous belief that socially constructed racial/ethnic groups constitute genetically and biologically distinct populations. Unequal care, particularly for common endocrine diseases such as diabetes, obesity, osteoporosis, and thyroid disease, results in high morbidity and mortality for individuals from racial/ethnic minority groups, leading to a high socioeconomic burden on minority communities and all members of our society. As health professionals, researchers, educators, and leaders, we have a responsibility to take action to eradicate racism from the healthcare system. Achieving this goal would result in high-quality health care services that are accessible to all, diverse workforces that are representative of the communities we serve, inclusive and equitable workplaces and educational settings that foster collaborative teamwork, and research systems that ensure that scientific advancements benefit all members of our society. The Endocrine Society will continue to prioritize and invest resources in a multifaceted approach to eradicate racism, focused on educating and engaging current and future health professionals, teachers, researchers, policy makers, and leaders.

Risk of Adverse Pregnancy Outcomes Among Pregnant Individuals With Gestational Diabetes by Race and Ethnicity in the United States, 2014-2020

IMPORTANCE

Gestational diabetes, which increases the risk of adverse pregnancy outcomes, has been increasing in frequency across all racial and ethnic subgroups in the US.

OBJECTIVE

To assess whether the frequency of adverse pregnancy outcomes among those in the US with gestational diabetes changed over time and whether the risk of these outcomes differed by maternal race and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

Exploratory serial, cross-sectional, descriptive study using US National Center for Health Statistics natality data for 1 560 822 individuals with gestational diabetes aged 15 to 44 years with singleton nonanomalous live births from 2014 to 2020 in the US.

EXPOSURES

Year of delivery and race and ethnicity, as reported on the birth certificate, stratified as non-Hispanic American Indian, non-Hispanic Asian/Pacific Islander, non-Hispanic Black, Hispanic/Latina, and non-Hispanic White (reference group).

MAIN OUTCOMES AND MEASURES

Maternal outcomes of interest included cesarean delivery, primary cesarean delivery, preeclampsia or gestational hypertension, intensive care unit (ICU) admission, and transfusion; neonatal outcomes included large for gestational age (LGA), macrosomia (>4000 g at birth), small for gestational age (SGA), preterm birth, and neonatal ICU (NICU) admission, as measured by the frequency (per 1000 live births) with estimation of mean annual percentage change (APC), disparity ratios, and adjusted risk ratios.

RESULTS

Of 1 560 822 included pregnant individuals with gestational diabetes (mean [SD] age, 31 [5.5] years), 1% were American Indian, 13% were Asian/Pacific Islander, 12% were Black, 27% were Hispanic/Latina, and 48% were White. From 2014 to 2020, there was a statistically significant increase in the overall frequency (mean APC per year) of preeclampsia or gestational hypertension (4.2% [95% CI, 3.3% to 5.2%]), transfusion (8.0% [95% CI, 3.8% to 12.4%]), preterm birth at less than 37 weeks (0.9% [95% CI, 0.3% to 1.5%]), and NICU admission (1.0% [95% CI, 0.3% to 1.7%]). There was a significant decrease in cesarean delivery (-1.4% [95% CI, -1.7% to -1.1%]), primary cesarean delivery (-1.2% [95% CI, -1.5% to -0.9%]), LGA (-2.3% [95% CI, -2.8% to -1.8%]), and macrosomia (-4.7% [95% CI, -5.3% to -4.0%]). There was no significant change in maternal ICU admission and SGA. In comparison with White individuals, Black individuals were at significantly increased risk of all assessed outcomes, except LGA and macrosomia; American Indian individuals were at significantly increased risk of all assessed outcomes except cesarean delivery and SGA; and Hispanic/Latina and Asian/Pacific Islander individuals were at significantly increased risk of maternal ICU admission, preterm birth, NICU admission, and SGA. Differences in adverse outcomes by race and ethnicity persisted through these years.

CONCLUSIONS AND RELEVANCE

From 2014 through 2020, the frequency of multiple adverse pregnancy outcomes in the US increased among pregnant individuals with gestational diabetes. Differences in adverse outcomes by race and ethnicity persisted.

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.

Physiological subtypes of gestational glucose intolerance and risk of adverse pregnancy outcomes

BACKGROUND

Women with gestational glucose intolerance, defined as an abnormal initial gestational diabetes mellitus screening test, are at risk of adverse pregnancy outcomes even if they do not have gestational diabetes mellitus. Previously, we defined the physiological subtypes of gestational diabetes mellitus based on the primary underlying physiology leading to hyperglycemia and found that women with different subtypes had differential risks of adverse outcomes. Physiological subclassification has not yet been applied to women with gestational glucose intolerance.

OBJECTIVE

We defined the physiological subtypes of gestational glucose intolerance based on the presence of insulin resistance, insulin deficiency, or mixed pathophysiology and aimed to determine whether these subtypes are at differential risks of adverse outcomes. We hypothesized that women with the insulin-resistant subtype of gestational glucose intolerance would have the greatest risk of adverse pregnancy outcomes.

STUDY DESIGN

In a hospital-based cohort study, we studied women with gestational glucose intolerance (glucose loading test 1-hour glucose, ≥140 mg/dL; n=236) and normal glucose tolerance (glucose loading test 1-hour glucose, <140 mg/dL; n=1472). We applied homeostasis model assessment to fasting glucose and insulin levels at 16 to 20 weeks' gestation to assess insulin resistance and deficiency and used these measures to classify women with gestational glucose intolerance into subtypes. We compared odds of adverse outcomes (large for gestational age birthweight, neonatal intensive care unit admission, pregnancy-related hypertension, and cesarean delivery) in each subtype to odds in women with normal glucose tolerance using logistic regression with adjustment for age, race and ethnicity, marital status, and body mass index.

RESULTS

Of women with gestational glucose intolerance (12% with gestational diabetes mellitus), 115 (49%) had the insulin-resistant subtype, 70 (27%) had the insulin-deficient subtype, 40 (17%) had the mixed pathophysiology subtype, and 11 (5%) were uncategorized. We found increased odds of large for gestational age birthweight (primary outcome) in women with the insulin-resistant subtype compared with women with normal glucose tolerance (odds ratio, 2.35; 95% confidence interval, 1.43-3.88; P=.001; adjusted odds ratio, 1.74; 95% confidence interval, 1.02-3.48; P=.04). The odds of large for gestational age birthweight in women with the insulin-deficient subtype were increased only after adjustment for covariates (odds ratio, 1.69; 95% confidence interval, 0.84-3.38; P=.14; adjusted odds ratio, 2.05; 95% confidence interval, 1.01-4.19; P=.048). Among secondary outcomes, there was a trend toward increased odds of neonatal intensive care unit admission in the insulin-resistant subtype in an unadjusted model (odds ratio, 2.09; 95% confidence interval, 0.99-4.40; P=.05); this finding was driven by an increased risk of neonatal intensive care unit admission in women with the insulin-resistant subtype and a body mass index of <25 kg/m². Infants of women with other subtypes did not have increased odds of neonatal intensive care unit admission. The odds of pregnancy-related hypertension in women with the insulin-resistant subtype were increased (odds ratio, 2.09; 95% confidence interval, 1.31-3.33; P=.002; adjusted odds ratio, 1.77; 95% confidence interval, 1.07-2.92; P=.03) compared with women with normal glucose tolerance; other subtypes did not have increased odds of pregnancy-related hypertension. There was no difference in cesarean delivery rates in nulliparous women across subtypes.

CONCLUSION

Insulin-resistant gestational glucose intolerance is a high-risk subtype for adverse pregnancy outcomes. Delineating physiological subtypes may provide opportunities for a more personalized approach to gestational glucose intolerance.

IDF Diabetes Atlas: The prevalence of pre-existing diabetes in pregnancy - A systematic reviewand meta-analysis of studies published during 2010-2020

OBJECTIVES

To estimate the prevalence of pre-existing diabetes in pregnancy from studies published during 2010-2020.

METHODS

We searched PubMed, CINAHL, Scopus and other sources for relevant data sources. The prevalence of overall pre-existing, type 1 and type 2 diabetes, by country, region and period of study was synthesised from included studies using the inverse-variance heterogeneity model and the Freeman-Tukey transformation. Heterogeneity was assessed using the I² statistic and publication bias using funnel plots.

RESULTS

We identified 2479 records, of which 42 data sources with a total of 78 943 376 women, met the eligibility criteria. The included studies were from 17 countries in North America, Europe, the Middle East and North Africa, Australasia, Asia and Africa. The lowest prevalence was in Europe (0.5%, 95 %CI 0.4-0.7) and the highest in the Middle East and North Africa (2.4%, 95 %CI 1.5-3.1). The prevalence of pre-existing diabetes doubled from 0.5% (95 %CI 0.1-1.0) to 1.0% (95 %CI 0.6-1.5) during the period 1990-2020. The pooled prevalences of pre-existing type 1 and type 2 diabetes were 0.3% (95 %CI 0.2-0.4) and 0.2% (95 %CI 0.0-0.9) respectively.

CONCLUSION

While the prevalence of pre-existing diabetes in pregnancy is low, it has doubled from 1990 to 2020.

Interventions to Mitigate Risk of Cardiovascular Disease After Adverse Pregnancy Outcomes: A Review

Importance

A growing body of evidence suggests that adverse pregnancy outcomes (APOs), including hypertensive disorders of pregnancy, gestational diabetes (GD), preterm birth, and intrauterine growth restriction, are associated with increased risk of cardiometabolic disease and cardiovascular disease (CVD) later in life. Adverse pregnancy outcomes may therefore represent an opportunity to intervene to prevent or delay onset of CVD. The objective of this review was to summarize the current evidence for targeted postpartum interventions and strategies to reduce CVD risk in women with a history of APOs.

Observations

A search of PubMed and Ovid for English-language randomized clinical trials, cohort studies, descriptive studies, and guidelines published from January 1, 2000, to April 30, 2021, was performed. Four broad categories of interventions were identified: transitional clinics, lifestyle interventions, pharmacotherapy, and patient and clinician education. Observational studies suggest that postpartum transitional clinics identify women who are at elevated risk for CVD and may aid in the transition to longitudinal primary care. Lifestyle interventions to increase physical activity and improve diet quality may help reduce the incidence of type 2 diabetes in women with prior GD; less is known about women with other prior APOs. Metformin hydrochloride may prevent development of type 2 diabetes in women with prior GD. Evidence is lacking in regard to specific pharmacotherapies after other APOs. Cardiovascular guidelines endorse using a history of APOs to refine CVD risk assessment and guide statin prescription for primary prevention in women with intermediate calculated 10-year CVD risk. Research suggests a low level of awareness of the link between APOs and CVD among both patients and clinicians.

Conclusions and Relevance

These findings suggest that transitional clinics, lifestyle intervention, targeted pharmacotherapy, and clinician and patient education represent promising strategies for improving postpartum maternal cardiometabolic health in women with APOs; further research is needed to develop and rigorously evaluate these interventions. Future efforts should focus on strategies to increase maternal postpartum follow-up, improve accessibility to interventions across diverse racial and cultural groups, expand awareness of sex-specific CVD risk factors, and define evidence-based precision prevention strategies for this high-risk population.

Sequencing Cell-free Fetal DNA in Pregnant Women With GCK-MODY

CONTEXT

Individuals with monogenic diabetes due to inactivating glucokinase (GCK) variants typically do not require treatment, except potentially during pregnancy. In pregnancy, fetal GCK genotype determines whether treatment is indicated, but noninvasive methods are not clinically available.

OBJECTIVE

This work aims to develop a method to determine fetal GCK genotype noninvasively using maternal cell-free fetal DNA.

METHODS

This was a proof-of-concept study involving 3 pregnant women with a causal GCK variant that used information from 1) massive parallel sequencing of maternal plasma cell-free DNA, 2) direct haplotype sequences of maternal genomic DNA, and 3) the paternal genotypes to estimate relative haplotype dosage of the pathogenic variant-linked haplotype. Statistical testing of variant inheritance was performed using a sequential probability ratio test (SPRT).

RESULTS

In each of the 3 cases, plasma cell-free DNA was extracted once between gestational weeks 24 and 36. The fetal fraction of cell-free DNA ranged from 21.8% to 23.0%. Paternal homozygous alleles that were identical to the maternal GCK variant-linked allele were not overrepresented in the cell-free DNA. Paternal homozygous alleles that were identical to the maternal wild-type-linked allele were significantly overrepresented. Based on the SPRT, we predicted that all 3 cases did not inherit the GCK variant. Postnatal infant genotyping confirmed our prediction in each case.

CONCLUSION

We have successfully implemented a noninvasive method to predict fetal GCK genotype using cell-free DNA in 3 pregnant women carrying an inactivating GCK variant. This method could guide tailoring of hyperglycemia treatment in pregnancies of women with GCK monogenic diabetes.

Relationship between carbohydrate intake and oral glucose tolerance test results among pregnant women

AIMS

Evaluate the relationship between self-reported carbohydrate intake and oral glucose tolerance test (OGTT) results in pregnancy.

METHODS

We measured carbohydrate intake using 24-hour dietary recall and performed a 2-hour 75-gram OGTT in 95 pregnant women with risk factors for gestational diabetes (GDM) at a median of 26 weeks' gestation. We tested for associations between carbohydrate intake in the 24 hours preceding the OGTT and 60-minute OGTT glucose, glucose at other timepoints, and glucose area under the curve (AUC) using linear regression, with adjustment for potential confounders.

RESULTS

We observed an inverse linear relationship between carbohydrate intake (median 237 grams [interquartile range: 196, 303]) and 60-minute OGTT glucose. For every 50 gram reduction in carbohydrate intake, there was an 8.9 mg/dl increase in 60-minute OGTT glucose (P < 0.01) in an adjusted model. Lower carbohydrate intake was also associated with higher 30-minute (adjusted β = -6.5 mg/dl, P < 0.01) and 120-minute OGTT glucose (adjusted β = -8.1 mg/dl, P = 0.01) and AUC (adjusted β = -767, P < 0.01).

CONCLUSIONS

Carbohydrate intake in the day preceding an OGTT in pregnancy is associated with post-load glucose values, with lower carbohydrate intake predicting higher glucose levels and higher carbohydrate intake predicting lower glucose levels. Carbohydrate restriction or excess before an OGTT may affect GDM diagnosis.

Epigenome-wide association study of maternal hemoglobin A1c in pregnancy and cord blood DNA methylation

Background: Gestational hyperglycemia is associated with adverse perinatal outcomes and long-term offspring metabolic programming, likely through dysregulation of DNA methylation (DNAm). Materials & methods: We tested associations between maternal HbA1c and cord blood DNAm among 412 mother-child pairs in the genetics of glucose regulation in gestation and growth (Gen3G) and implemented Mendelian randomization to infer causality. We sought replication in an independent sample from Healthy Start. Results: Higher second trimester HbA1c levels were associated with lower DNAm at cg21645848 (p = 3.9 × 10^-11) near URGCP. Mendelian randomization and replication analyses showed same direction of effect between HbA1c and DNAm at cg21645848, but did not reach statistical significance. Conclusion: We found that higher maternal glycemia reflected by HbA1c is associated with cord blood DNAm at URGCP, a gene related with inflammatory pathways.

Genetic Loci and Physiologic Pathways Involved in Gestational Diabetes Mellitus Implicated Through Clustering

Hundreds of common genetic variants acting through distinguishable physiologic pathways influence the risk of type 2 diabetes (T2D). It is unknown to what extent the physiology underlying gestational diabetes mellitus (GDM) is distinct from that underlying T2D. In this study of >5,000 pregnant women from three cohorts, we aimed to identify physiologically related groups of maternal variants associated with GDM using two complementary approaches that were based on Bayesian nonnegative matrix factorization (bNMF) clustering. First, we tested five bNMF clusters of maternal T2D-associated variants grouped on the basis of physiology outside of pregnancy for association with GDM. We found that cluster polygenic scores representing genetic determinants of reduced β-cell function and abnormal hepatic lipid metabolism were associated with GDM; these clusters were not associated with infant birth weight. Second, we derived bNMF clusters of maternal variants on the basis of pregnancy physiology and tested these clusters for association with GDM. We identified a cluster that was strongly associated with GDM as well as associated with higher infant birth weight. The effect size for this cluster's association with GDM appeared greater than that for T2D. Our findings imply that the genetic and physiologic pathways that lead to GDM differ, at least in part, from those that lead to T2D.

Genetic Studies of Gestational Diabetes and Glucose Metabolism in Pregnancy

PURPOSE OF REVIEW

In this review, we summarize studies investigating genetics of gestational diabetes mellitus (GDM) and glucose metabolism in pregnancy. We describe these studies in the context of the larger body of literature on type 2 diabetes (T2D) and glycemic trait genomics.

RECENT FINDINGS

We reviewed 23 genetic association studies for GDM and performed a meta-analysis, which revealed variants at eight T2D loci significantly associated with GDM after the Bonferroni correction. These studies suggest that GDM and T2D share a number of genetic risk loci. Only two unbiased genome-wide association studies (GWASs) have successfully revealed genetic associations for GDM and related glycemic traits in pregnancy. A GWAS for GDM in Korean women identified two loci (near CDKAL1 and MTNR1B) known to be associated with T2D, though the association of the MTNR1B locus with GDM appears to be stronger than that for T2D. A multi-ethnic GWAS for glycemic traits in pregnancy identified two novel loci (near HKDC1 and BACE2) which appear to be associated with post-load glucose and fasting c-peptide specifically in pregnant women. There are ongoing efforts to use this genetic information, in the form of polygenic scores, to predict risk of GDM and postpartum T2D. The body of literature examining genetic associations with GDM is limited, especially when compared to the available literature on T2D and glycemic trait genomics. Additional genetic discovery for glucose metabolism in pregnant women will require larger pregnancy cohorts and international collaborative efforts. Studies on the clinical implications of these findings are also warranted.

Defining Heterogeneity Among Women With Gestational Diabetes Mellitus

Attention to precision medicine in type 2 diabetes (T2D) has provided two favored approaches to subclassifying affected individuals and parsing heterogeneity apparent in this condition: phenotype-based and genotype-based. Gestational diabetes mellitus (GDM) shares phenotypic characteristics with T2D. However, unlike T2D, GDM emerges in the setting of profound pregnancy-related physiologic changes in glucose metabolism. T2D and GDM also share common genetic architecture, but there are likely to be unique genetic influences on pregnancy glycemic regulation that contribute to GDM. In this Perspective, we describe efforts to decipher heterogeneity in T2D and detail how we and others are applying approaches developed for T2D to the study of heterogeneity in GDM. Emerging results reveal the potential of phenotype- and genotype-based subclassification of GDM to deliver the promise of precision medicine to the obstetric population.

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.