Perinatal Outcomes of Two Screening Strategies for Gestational Diabetes Mellitus: A Randomized Controlled Trial

Maternal and neonatal outcomes with different screening strategies for gestational diabetes mellitus: a retrospective cohort study

OBJECTIVE

To evaluate the effect of an expanded gestational diabetes mellitus (GDM) screening strategy on perinatal outcomes.

METHODS

This retrospective cohort study included gravidas screened for GDM at a single academic center. The "before" cohort (estimated due dates (EDD) March 2018-April 2019) was screened using the standard 2-step method. The "after" cohort (EDD November 2019-July 2023) was screened using an expanded strategy that included the potential for GDM diagnosis based on 1-2 weeks of home glucose monitoring following isolated fasting hyperglycemia on the 3-hour glucose tolerance test (GTT). The primary outcomes were primary cesarean delivery (PCD) and neonatal intensive care unit (NICU) admission. Binomial regression and Kruskal Wallis tests were used to compare perinatal outcomes between the two cohorts in the general population and in a subgroup of those with isolated fasting hyperglycemia.

RESULTS

Outcomes for the "before" cohort (n = 1,733) were compared with those in the "after" cohort (n = 6,280). In the general population, A2GDM incidence increased after expansion of the screening protocol (4.8% vs. 6.4%, RR 1.34, 95% CI 1.07-1.69), but PCD and NICU admission rates were unchanged. In the subgroup of patients with isolated fasting hyperglycemia (n = 233), there was a significant increase in the incidence of any GDM (12.5 vs. 46.0%, RR 3.68, 95% CI 1.95-6.93) and A2GDM (8.3% vs. 37.3%, RR 4.47, 95% CI 2.03-9.87). There was no difference in PCD between cohorts, but NICU admission increased significantly in the "after" cohort (8.3% vs 22.4%, RR 2.68, 95% CI 1.18-6.08) in this subgroup.

CONCLUSION

An expanded approach to GDM diagnosis using home blood glucose monitoring following isolated fasting hyperglycemia on 3-hour GTT was associated with increased A2GDM incidence but no improvements in primary maternal or neonatal outcomes. In the absence of clinical benefit, we do not recommend widespread implementation of this expanded strategy.

The Association Between Midpregnancy Food Intake Timing Patterns and Gestational Weight Gain

Background: This article aims to characterize midpregnancy food timing profiles and examine their association with gestational weight gain (GWG). Materials and Methods: This secondary data analysis of a randomized controlled trial of two gestational diabetes screening approaches included 641 individuals with primary exposures and outcomes data. Food timing indicators (i.e., first and last eating episode time, caloric midpoint time, and the total eating window) were assessed using two 24-hour dietary recalls conducted in midpregnancy. Latent profile analysis was used to identify distinct food timing profiles based on these indicators. Regression analyses explored the associations between individual food intake timing indicators, food timing profiles, and GWG. Results: We identified four food timing profiles: extended window eating (n = 133; earliest first eating episode and the longest eating window), restricted window eating (n = 120; latest first eating episode and shortest eating window), early eating (n = 188; earliest caloric midpoint), and typical eating (n = 200; food intake aligning with the sample median). Participants with a restricted window eating profile (vs. typical eating profile) had an increased risk of insufficient GWG (unadjusted relative risk [RR] = 1.85, 95% confidence interval [CI] 1.12, 3.05). Each hour increase in the timing of the last eating episode was associated with 0.39 kg (0.03, 0.75) higher GWG. Both associations were attenuated in adjusted models and no longer statistically significant in adjusted models. Conclusions: We identified four distinct midpregnancy food timing profiles, but these profiles were not independently associated with GWG. These findings suggest that midpregnancy food timing may not play a major role in GWG.

Gestational diabetes mellitus - more than the eye can see - a warning sign for future maternal health with transgenerational impact

Gestational diabetes mellitus (GDM) is regarded by many as maternal maladaptation to physiological insulin resistance during the second half of pregnancy. However, recent evidence indicates that alterations in carbohydrate metabolism can already be detected in early pregnancy. This observation, the increasing prevalence of GDM, and the significant short and long-term implications for the mother and offspring call for reevaluation of the conceptual paradigm of GDM as a syndrome. This review will present evidence for the syndromic nature of GDM and the controversies regarding screening, diagnosis, management, and treatment.

The Hidden Impact of Gestational Diabetes: Unveiling Offspring Complications and Long-Term Effects

BACKGROUND

Gestational diabetes mellitus (GDM), characterized by gestational hyperglycemia due to insufficient insulin response, poses significant risks to both maternal and offspring health. Fetal exposure to maternal hyperglycemia leads to short-term complications such as macrosomia and neonatal hypoglycemia and long-term risks including obesity, metabolic syndrome, cardiovascular dysfunction, and type 2 diabetes. The Developmental Origins of Health and Disease (DOHaD) theory explains how maternal hyperglycemia alters fetal programming, increasing susceptibility to metabolic disorders later in life.

OBJECTIVE

This review explores the intergenerational impact of GDM, linking maternal hyperglycemia to lifelong metabolic, cardiovascular, and neurodevelopmental risks via epigenetic and microbiome alterations. It integrates the most recent findings, contrasts diagnostic methods, and offers clinical strategies for early intervention and prevention.

METHODS

A comprehensive literature search was conducted in PubMed, Scopus, and ScienceDirect to identify relevant studies published between 1 January 2000 and 31 December 2024. The search included studies focusing on the metabolic and developmental consequences of GDM exposure in offspring, as well as potential mechanisms such as epigenetic alterations and gut microbiota dysbiosis. Studies examining preventive strategies and management approaches were also included.

KEY FINDINGS

Maternal hyperglycemia leads to long-term metabolic changes in offspring, with epigenetic modifications and gut microbiota alterations playing key roles. GDM-exposed children face increased risks of obesity, glucose intolerance, and cardiovascular diseases. Early screening and monitoring are crucial for risk reduction.

PRACTICAL IMPLICATIONS

Understanding the intergenerational effects of GDM has important clinical implications for prenatal and postnatal care. Early detection, lifestyle interventions, and targeted postnatal surveillance are essential for reducing long-term health risks in offspring. These findings emphasize the importance of comprehensive maternal healthcare strategies to improve long-term outcomes for both mothers and their children.

A framework to classify gestational diabetes diagnosed by routine antenatal 75g glucose tolerance testing

OBJECTIVE

To create an objective framework to classify gestational diabetes mellitus diagnosed by routine antenatal 75 g diabetes testing results to provide an alternative to current treatment-based classification.

METHODS

A framework was created to classify gestational diabetes according to the severity of glycemic abnormalities after routine antenatal 75 g GTT (classes 1 through 4, determined by fasting and post-test glycemic abnormalities). A retrospective cohort chart review was used to correlate clinically how often diet therapy alone maintained glycemic targets throughout pregnancy in each class. Chi-square analysis was used to assess inter-class differences in the success of diet therapy alone maintaining glycemic targets throughout pregnancy.

RESULTS

Seventy-four of 228 (33%), 35/228 (15%), 76/228 (33%), and 43/228 (19%) of the study population were classified as Class 1, 2, 3, or 4, respectively. Of eighty-nine patients who maintained glycemic targets throughout pregnancy with diet alone 51/89 (57%) were Class 1, 20/89 (22.5%) were Class 2, 11/89 (12.5%) were Class 3, and 7/89 (8%) were Class 4. Chi-square analysis showed statistically significant inter-class differences in the likelihood of diet therapy alone maintaining glycemic targets throughout pregnancy.

CONCLUSION

In this framework classifying gestational diabetes according to the severity of glycemic abnormalities after routine antenatal 75 g GTT (an objective proxy for disease severity), the higher the assigned class, the less likely that diet therapy alone maintained glycemic targets throughout pregnancy (a clinical proxy for disease severity).

Problems in screening for gestational diabetes mellitus by measurement of casual blood glucose levels at 24-28 gestational weeks

AIMS/INTRODUCTION

This study aimed to evaluate the problems in screening for gestational diabetes mellitus (GDM) by casual blood glucose (CBG) measurements at 24-28 gestational weeks.

MATERIALS AND METHODS

Overall, 763 pregnant women who underwent the 50-g glucose challenge test (GCT) at 24-28 gestational weeks were enrolled. The preload blood glucose (0-h BG) level of 50-g GCT was considered as CBG.

RESULTS

A total of 240 women with BG levels at 1-h after loading (1-h BG) on 50-g GCT ≥140 mg/dL underwent the 75-g oral glucose tolerance test, and 98 (40.8%) were diagnosed with GDM. Of the 99 women with GDM, 71 (71.7%) had 0-h BG on 50-g GCT <100 mg/dL.

CONCLUSIONS

This study, where pregnant women underwent both CBG and 50-g GCT simultaneously, showed that when CBG at 24-28 gestational weeks ≥100 mg/dL alone was used for screening GDM, many pregnant women with GDM were overlooked.

Association of ideal cardiovascular health and history of gestational diabetes mellitus in NHANES 2007-2018

BACKGROUND

Population-based studies of ideal cardiovascular health (CVH) and gestational diabetes mellitus (GDM) are scarce.

METHODS

We conducted a cross-sectional analysis of 2007-2018 National Health Examination and Nutrition Survey women aged ≥ 20 years, who had data on Life's Simple 7 (LS7) metrics and self-reported GDM history. Each LS7 metric was assigned a score of 0 (non-ideal) and 1(ideal) and summed to obtain total ideal CVH scores (0-7). We used logistic regression models to assess associations between LS7 ideal CVH scores (0-7) and GDM history, accounting for socio-demographic factors.

RESULTS

Among 9199 women (mean age: 46 years, 8 % with a GDM history), there was a progressive decrease in the odds of past GDM history across increasing ideal CVH scores. Compared to females with 0-1 ideal CVH scores, females with ideal CVH scores of 3, 4 and 5-7 had an associated 39 % lower [odds ratio: 0.61 (95 % CI: 0.41-0.90)], 50 % lower [0.50 (0.33-0.76)] and 66 % lower [0.34 (0.20-0.56)] odds of past GDM history, respectively. There were notable racial/ethnic and citizenship/nativity differences in these associations.

CONCLUSIONS

Women with higher ideal CVH scores had lower odds of GDM history. Our findings underscore the importance of optimizing cardiometabolic health among women with GDM history.

Metabolic factors and perinatal outcomes among pregnant individuals with mild glucose intolerance

AIMS

Metabolic characteristics and outcomes were compared among pregnant individuals with varying levels of glucose intolerance.

METHODS

827 participants from a randomized clinical trial comparing the IADPSG and Carpenter Coustan Criteria were grouped as follows: normal glucose tolerance, mild glucose intolerance (100 g OGTT with one abnormal value) and treated GDM (diagnosed by Carpenter Coustan or IADPSG criteria). Differences in metabolic characteristics and perinatal outcomes were assessed using inverse probability of treatment weighting.

RESULTS

Mild glucose intolerance had lower insulin sensitivity and beta cell response than normal glucose tolerance, and similar findings to treated GDM. Small for gestational age (SGA) (OR 0.13, 95% CI 0.08-0.24) and neonatal composite morbidity were lower (OR 0.53, 95% CI 0.38-0.74), and maternal composite morbidity higher (OR 2.03, 95% CI 1.57-2.62) when comparing mild intolerance to normal glucose tolerance. Large for gestational age (OR 3.42 95% CI 1.39-8.41) was higher while SGA (OR 0.21, 95% CI 0.05-0.81) and neonatal composite morbidity (OR 0.31, 95% CI 0.17-0.57) were lower with mild glucose intolerance compared to treated GDM.

CONCLUSIONS

Mild glucose intolerance has a similar metabolic profile to treated GDM, and outcome differences are likely related to knowledge of diagnosis and treatment.

CLINICAL TRIALS REGISTRY

NCT02309138.

Diagnosis and Treatment of Hyperglycemia in Pregnancy: Type 2 Diabetes Mellitus and Gestational Diabetes

Hyperglycemia in pregnancy due to pre-existing Type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM) is rising globally with increasing rates of risk factors for metabolic disease. This review summarizes current evidence and recommendations from national and international guidelines for diagnosis and management of T2DM and GDM to optimize maternal and neonatal outcomes.

Gestational diabetes as a risk factor for GBS maternal rectovaginal colonization: a systematic review and meta-analysis

BACKGROUND

Maternal rectovaginal colonization by group B Streptococcus (GBS) increases the risk of perinatal GBS disease that can lead to death or long-term neurological impairment. Factors that increase the risk of rectovaginal GBS carriage are incompletely understood resulting in missed opportunities for detecting GBS in risk-based clinical approaches. There is a lacking consensus on whether gestational diabetes mellitus (GDM) is a risk factor for rectovaginal GBS. This systematic review and meta-analysis aims to address current conflicting findings and determine whether GDM should be clinically considered as a risk factor for maternal GBS colonization.

METHODS

Peer-reviewed studies that provided GDM prevalence and documented GBS vaginal and/or rectal colonization in women with and without GDM were included in this analysis. From study inception to October 30, 2023, we identified 6,275 relevant studies from EMBASE and PUBMED of which 19 were eligible for inclusion. Eligible studies were analyzed and thoroughly assessed for risk of bias with a modified Newcastle-Ottawa Scale that interrogated representativeness and comparability of cohorts, quality of reporting for GDM and GBS status, and potential bias from other metabolic diseases. Results were synthesized using STATA 18 and analyzed using random-effects meta-analyses.

RESULTS

Studies encompassed 266,706 women from 10 different countries, with study periods spanning from 1981 to 2020. Meta-analysis revealed that gestational diabetes is associated with a 16% increased risk of rectovaginal GBS carriage (OR 1.16, CI 1.07-1.26, P = 0.003). We also performed subgroup analyses to assess independent effects of pregestational vs. gestational diabetes on risk of maternal GBS carriage. Pregestational diabetes (Type 1 or Type 2 diabetes mellitus) was also associated with an increased risk of 76% (pooled OR 1.76, CI 1.27-2.45, P = 0.0008).

CONCLUSIONS

This study achieved a consensus among previously discrepant observations and demonstrated that gestational diabetes and pregestational diabetes are significant risk factors for maternal rectovaginal carriage of GBS. Recognition of GDM as a risk factor during clinical decisions about GBS screening and intrapartum antibiotic prophylaxis may decrease the global burden of GBS on maternal-perinatal health.

Call to action for a life course approach

Gestational diabetes remains the most common medical disorder in pregnancy, with short-term and long-term consequences for mothers and offspring. New insights into pathophysiology and management suggest that the current gestational diabetes treatment approach should expand from a focus on late gestational diabetes to a personalised, integrated life course approach from preconception to postpartum and beyond. Early pregnancy lifestyle intervention could prevent late gestational diabetes. Early gestational diabetes diagnosis and treatment has been shown to be beneficial, especially when identified before 14 weeks of gestation. Early gestational diabetes screening now requires strategies for integration into routine antenatal care, alongside efforts to reduce variation in gestational diabetes care, across settings that differ between, and within, countries. Following gestational diabetes, an oral glucose tolerance test should be performed 6-12 weeks postpartum to assess the glycaemic state. Subsequent regular screening for both dysglycaemia and cardiometabolic disease is recommended, which can be incorporated alongside other family health activities. Diabetes prevention programmes for women with previous gestational diabetes might be enhanced using shared decision making and precision medicine. At all stages in this life course approach, across both high-resource and low-resource settings, a more systematic process for identifying and overcoming barriers to preventative care and treatment is needed to reduce the current global burden of gestational diabetes.

Changing diagnostic criteria for gestational diabetes (CDC4G) in Sweden: A stepped wedge cluster randomised trial

BACKGROUND

The World Health Organisation (WHO) 2013 diagnostic criteria for gestational diabetes mellitus (GDM) has been criticised due to the limited evidence of benefits on pregnancy outcomes in different populations when switching from previously higher glycemic thresholds to the lower WHO-2013 diagnostic criteria. The aim of this study was to determine whether the switch from previous Swedish (SWE-GDM) to the WHO-2013 GDM criteria in Sweden following risk factor-based screening improves pregnancy outcomes.

METHODS AND FINDINGS

A stepped wedge cluster randomised trial was performed between January 1 and December 31, 2018 in 11 clusters (17 delivery units) across Sweden, including all pregnancies under care and excluding preexisting diabetes, gastric bypass surgery, or multifetal pregnancies from the analysis. After implementation of uniform clinical and laboratory guidelines, a number of clusters were randomised to intervention (switch to WHO-2013 GDM criteria) each month from February to November 2018. The primary outcome was large for gestational age (LGA, defined as birth weight >90th percentile). Other secondary and prespecified outcomes included maternal and neonatal birth complications. Primary analysis was by modified intention to treat (mITT), excluding 3 clusters that were randomised before study start but were unable to implement the intervention. Prespecified subgroup analysis was undertaken among those discordant for the definition of GDM. Multilevel mixed regression models were used to compare outcome LGA between WHO-2013 and SWE-GDM groups adjusted for clusters, time periods, and potential confounders. Multiple imputation was used for missing potential confounding variables. In the mITT analysis, 47 080 pregnancies were included with 6 882 (14.6%) oral glucose tolerance tests (OGTTs) performed. The GDM prevalence increased from 595/22 797 (2.6%) to 1 591/24 283 (6.6%) after the intervention. In the mITT population, the switch was associated with no change in primary outcome LGA (2 790/24 209 (11.5%) versus 2 584/22 707 (11.4%)) producing an adjusted risk ratio (aRR) of 0.97 (95% confidence interval 0.91 to 1.02, p = 0.26). In the subgroup, the prevalence of LGA was 273/956 (28.8%) before and 278/1 239 (22.5%) after the switch, aRR 0.87 (95% CI 0.75 to 1.01, p = 0.076). No serious events were reported. Potential limitations of this trial are mainly due to the trial design, including failure to adhere to guidelines within and between the clusters and influences of unidentified temporal variations.

CONCLUSIONS

In this study, implementing the WHO-2013 criteria in Sweden with risk factor-based screening did not significantly reduce LGA prevalence defined as birth weight >90th percentile, in the total population, or in the subgroup discordant for the definition of GDM. Future studies are needed to evaluate the effects of treating different glucose thresholds during pregnancy in different populations, with different screening strategies and clinical management guidelines, to optimise women's and children's health in the short and long term.

TRIAL REGISTRATION

The trial is registered with ISRCTN (41918550).

Risk of Neonatal Hypoglycemia in Infants of Mothers With Gestational Glucose Intolerance

OBJECTIVE

To examine the relationship between gestational glucose intolerance (GGI) and neonatal hypoglycemia.

RESEARCH DESIGN AND METHODS

This was a secondary analysis of 8,262 mother-infant dyads, with delivery at two hospitals between 2014 and 2023. We categorized maternal glycemic status as normal glucose tolerance (NGT), GGI, or gestational diabetes mellitus (GDM). We defined NGT according to a normal glucose load test result, GGI according to an abnormal glucose load test result with zero (GGI-0) or one (GGI-1) abnormal value on the 100-g oral glucose tolerance test, and GDM according to an abnormal glucose load test result with two or more abnormal values on the glucose tolerance test. Neonatal hypoglycemia was defined according to blood glucose <45 mg/dL or ICD-9 or ICD-10 diagnosis of neonatal hypoglycemia. We used logistic regression analysis to determine associations between maternal glucose tolerance category and neonatal hypoglycemia and conducted a sensitivity analysis using Δ-adjusted multiple imputation, assuming for unscreened infants a rate of neonatal hypoglycemia as high as 33%.

RESULTS

Of infants, 12% had neonatal hypoglycemia. In adjusted models, infants born to mothers with GGI-0 had 1.28 (95% 1.12, 1.65), GGI-1 1.58 (95% CI 1.11, 2.25), and GDM 4.90 (95% CI 3.81, 6.29) times higher odds of neonatal hypoglycemia in comparison with infants born to mothers with NGT. Associations in sensitivity analyses were consistent with the primary analysis.

CONCLUSIONS

GGI is associated with increased risk of neonatal hypoglycemia. Future research should include examination of these associations in a cohort with more complete neonatal blood glucose ascertainment and determination of the clinical significance of these findings on long-term child health.

Design, rationale and protocol for Glycemic Observation and Metabolic Outcomes in Mothers and Offspring (GO MOMs): an observational cohort study

INTRODUCTION

Given the increasing prevalence of both obesity and pre-diabetes in pregnant adults, there is growing interest in identifying hyperglycaemia in early pregnancy to optimise maternal and perinatal outcomes. Multiple organisations recommend first-trimester diabetes screening for individuals with risk factors; however, the benefits and drawbacks of detecting glucose abnormalities more mild than overt diabetes in early gestation and the best screening method to detect such abnormalities remain unclear.

METHODS AND ANALYSIS

The goal of the Glycemic Observation and Metabolic Outcomes in Mothers and Offspring study (GO MOMs) is to evaluate how early pregnancy glycaemia, measured using continuous glucose monitoring and oral glucose tolerance testing, relates to the diagnosis of gestational diabetes (GDM) at 24-28 weeks' gestation (maternal primary outcome) and large-for-gestational-age birth weight (newborn primary outcome). Secondary objectives include relating early pregnancy glycaemia to other adverse pregnancy outcomes and comprehensively detailing longitudinal changes in glucose over the course of pregnancy. GO MOMs enrolment began in April 2021 and will continue for 3.5 years with a target sample size of 2150 participants.

ETHICS AND DISSEMINATION

GO MOMs is centrally overseen by Vanderbilt University's Institutional Review Board and an Observational Study Monitoring Board appointed by National Institute of Diabetes and Digestive and Kidney Diseases. GO MOMs has potential to yield data that will improve understanding of hyperglycaemia in pregnancy, elucidate better approaches for early pregnancy GDM screening, and inform future clinical trials of early GDM treatment.

TRIAL REGISTRATION NUMBER

NCT04860336.

One-step vs 2-step gestational diabetes mellitus screening and pregnancy outcomes: an updated systematic review and meta-analysis

OBJECTIVE

This was a systematic review and meta-analysis comparing maternal and neonatal outcomes of patients screened with the 1-step or 2-step screening method for gestational diabetes mellitus.

DATA SOURCES

PubMed, Scopus, Cochrane, ClinicalTrials.gov, and LILACS were searched from inception up to September 2022.

STUDY ELIGIBILITY CRITERIA

Only randomized controlled trials were included. Studies that had overlapping populations were excluded (International Prospective Register of Systematic Review registration number: CRD42022358903).

METHODS

Risk ratios were computed with 95% confidence intervals by 2 authors. Unpublished data were requested. Large for gestational age was the primary outcome.

RESULTS

The search yielded 394 citations. Moreover, 7 randomized controlled trials met the inclusion criteria. A total of 54,650 participants were screened for gestational diabetes mellitus by either the 1-step screening method (n=27,163) or the 2-step screening method (n=27,487). For large for gestational age, there was no significant difference found between the groups (risk ratio, 0.99; 95% confidence interval, 0.93-1.05; I2=0%). Newborns of patients who underwent 1-step screening had higher rates of neonatal hypoglycemia (risk ratio, 1.24; 95% confidence interval, 1.14-1.34; I2=0%) and neonatal intensive care unit admissions (risk ratio, 1.13; 95% confidence interval, 1.04-1.21; I2=0%) than newborns of patients who underwent 2-step screening. Patients in the 1-step screening method group were more likely to be diagnosed with gestational diabetes mellitus (risk ratio, 1.73; 95% confidence interval, 1.44-2.09; I2=80%) than patients in the 2-step screening method group. In addition, among trials that tested all patients before randomization and excluded patients with pregestational diabetes mellitus, newborns were more likely to have macrosomia (risk ratio, 1.27; 95% confidence interval, 1.21-1.34; I2=0%). Overall risk of bias assessment was of low concern.

CONCLUSION

Large for gestational age did not differ between patients screened using the 1-step screening method and those screened using the 2-step screening method. However, patients randomized to the 1-step screening method had higher rates of neonatal hypoglycemia and neonatal intensive care unit admission and maternal gestational diabetes mellitus diagnosis than the patients randomized to the 2-step screening method.

Do WHO criteria for gestational diabetes fit a rural population in Tanzania? - A follow-up study assessing mother and child health six years after a pregnancy diagnosed with gestational diabetes

AIMS AND METHODS

In low- and middle- income countries (LMICs) consequences of gestational diabetes (GDM) is understudied. Using a prospective cohort of mothers (n = 197)and children (n = 251), from rural north-eastern Tanzania, we assessed prediabetes and type 2 diabetes (T2D) prevalence six years after a pregnancy with/without GDM.

RESULTS

The prevalence of prediabetes (49.4 % vs. 46.4 %) orT2D (20.0 % vs. 16.1 %), p ≥ 0.36, based on fasting plasma glucose (FPG) or HbA1clevels (prediabetes: 16.9 % vs. 13.8 % and T2D 1.2 % vs. 0 %, p = 0.47), andcardio-metabolic health parameters,weresimilar between women with/without previous GDM. These results were supported by similar perinatal outcomes and child health at follow-up.The overall prevalence ofprediabetes/T2D was high, but no differences in other cardio-metabolic risk markers were observed in women with prediabetes/T2D compared to women with normal glucose tolerance.

CONCLUSIONS

Despite high prevalence of GDM amongTanzanian women, the diagnosis was not associated with adverse pregnancy outcomes, nor with increased risk of prediabetes or T2D at follow-up. FPG and HbA1c may be poor markers for diabetes in this population, and further follow-up studies with longer time intervals are warranted to evaluate which GDM diagnostic criteria are most optimal for women in rural Tanzania and similar LMIC settings.

Routine screening for gestational diabetes: a review

PURPOSE OF REVIEW

Rates of gestational diabetes mellitus (GDM) throughout the world continue to increase associated with the increasing rates of obesity. Given this epidemiologic burden, the importance of proper screening, diagnosis, and management cannot be understated. This review focuses on the current screening guidelines utilized throughout the world and new data recently published regarding the most optimal screening techniques and future directions for research.

RECENT FINDINGS

Despite unanimous opinion that GDM warrants screening, the optimal screening regimen remains controversial. Notably, in the United States per the consensus recommendation by the American College of Obstetrics and Gynecology and the Society for Maternal-Fetal Medicine, a 2-step screening approach is often used. Recently, there have been multiple studies published that have compared the 1-step and 2-step screening process with respect to GDM incidence and perinatal outcomes. These new findings are summarized below.

SUMMARY

Utilization of the 1-step screening as opposed to the 2-step screening results in an increased diagnosis of GDM without significant population level benefit in outcomes. However, these studies remain underpowered to allow for meaningful comparison of outcomes in those diagnosed with GDM.

Comparative Assessment of Exclusive Breastfeeding Rates From 24-Hour Recall and Since Birth Methods in Southwestern Pennsylvania Using Ecological Momentary Assessment

BACKGROUND

Accurate measurement of exclusive breastfeeding is important in maternal and child health research. Exclusive breastfeeding is often measured using the 24-hour recall or the since birth method for the first 6 months. These methods can produce different estimates, introducing problems in interpreting breastfeeding behavior and making accurate comparisons across settings or countries.

RESEARCH AIM

Our aim was to compare the exclusive breastfeeding rates between the 24-hour recall and since birth methods among a diverse cohort of birthing people using the ecological momentary assessments method. In addition, we compared the exclusive breastfeeding rates between the two methods across race and other maternal characteristics.

METHODS

This study is a secondary analysis using data from the Postpartum Mothers Mobile Study (PMOMS), a prospective longitudinal study which recruited participants during pregnancy and followed them for 12 months after delivery. Participants completed surveys in real-time via ecological momentary assessment. Individual exclusive breastfeeding rates from months 1-6 were computed using 24-hour recall and since birth methods for 284 participants. We calculated the percentage point difference between the two methods across child age and maternal characteristics. We used a two-sample test of proportions to determine if the differences observed in the proportions were significant.

RESULTS

Exclusive breastfeeding rates from the 24-hour recall were higher than the since birth rates across all ages and maternal characteristics. The difference between the two methods at 3 months was 25.7 percentage points and at 6 months was a 17.2 percentage points. Irrespective of the method used to measure exclusive breastfeeding, White participants had higher exclusive breastfeeding rates than Black participants.

CONCLUSION

The 24-hour recall and the since birth methods of assessing exclusive breastfeeding provided substantially different estimates. These findings highlight the importance of specificity in measuring and reporting exclusive breastfeeding.

Examining demographic and psychosocial factors related to self-weighing behavior during pregnancy and postpartum periods

Black childbearing individuals in the US experience a higher risk of postpartum weight retention (PPWR) compared to their White counterparts. Given that PPWR is related to adverse health outcomes, it is important to investigate predictors of weight-related health behaviors, such as self-weighing (i.e., using a scale at home). Regular self-weighing is an evidence-based weight management strategy, but there is minimal insight into sociodemographic factors related to frequency. The Postpartum Mothers Mobile Study (PMOMS) facilitated longitudinal ambulatory weight assessments to investigate racial inequities in PPWR. Our objective for the present study was to describe self-weighing behavior during and after pregnancy in the PMOMS cohort, as well as related demographic and psychosocial factors. Applying tree modeling and multiple regression, we examined self-weighing during and after pregnancy. Participants (N = 236) were 30.2 years old on average (SD = 4.7), with the majority being college-educated (53.8%, n = 127), earning at least $30,000 annually (61.4%, n = 145), and self-identifying as non-Hispanic White (NHW; 68.2%, n = 161). Adherence to regular self-weighing (at least once weekly) was highest among participants during pregnancy, with a considerable decline after giving birth. Low-income Black participants (earning < $30,000) were significantly less likely to reach a completion rate of ≥ 80% during pregnancy (AOR = 0.10) or the postpartum period (AOR = 0.16), compared to NHW participants earning at least $30,000 annually. Increases in perceived stress were associated with decreased odds of sustained self-weighing after delivery (AOR = 0.79). Future research should consider behavioral differences across demographic intersections, such as race and socioeconomic status, and the impact on efficacy of self-weighing.

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.

Prevalence of gestational diabetes mellitus, maternal obesity and associated perinatal outcomes over 10 years in an Australian tertiary maternity provider

BACKGROUND

The International Association of Diabetes in Pregnancy Study Groups (IADPSG) gestational diabetes mellitus (GDM) criteria have been heavily scrutinised with concerns that the consequent GDM prevalence increase has not been associated with improved perinatal outcomes.

AIMS

At a tertiary hospital in Melbourne, Australia we aimed to evaluate prevalence trends for GDM, type 2 diabetes (T2DM), maternal obesity and large-for-gestational age (LGA) and assess changes in perinatal outcomes following IADPSG criteria uptake in 2015.

METHODS

A retrospective cohort study of singleton births from 20 weeks' gestation was conducted between 1st January 2011 and 31st December 2020. Maternal characteristics and perinatal outcomes were extracted from medical records.

RESULTS

52,795 pregnancies were included. GDM prevalence increased 2.7 times from 8.9% in 2011 to 23.7% in 2020 and increased annually by 8.59% (95%CI 7.77, 9.42). The rate of T2DM increased annually by 11.69% (95%CI 7.72, 16.67). Obesity prevalence increased annually by 3.18% (95%CI 2.58, 3.78). Induction of labour (IOL) prevalence increased annually by 8.35% (95%CI 5.69, 11.06). LGA prevalence remained unchanged. Increasing maternal obesity was the major contributing factor for LGA prevalence.

CONCLUSIONS

From 2011 to 2020 GDM, obesity and T2DM prevalence increased significantly, with associated increased IOL, without change in LGA rates. Prospective studies are required to explore interactions between GDM, obesity, LGA and obstetric interventions.

Treatment of women with mild gestational diabetes mellitus decreases the risk of adverse perinatal outcomes

AIMS

Glycemic thresholds used to diagnose gestational diabetes mellitus (GDM) are a continued subject of debate. Lower glycemic thresholds identify women with milder GDM for whom treatment benefit is unclear. We compared adverse maternal and neonatal outcomes in treated and untreated women with mild hyperglycemia.

METHODS

We reviewed 11 553 patient charts from two tertiary care centers and included singleton pregnancies >32-week gestation. GDM was diagnosed using the one- or two-step 75 g oral glucose tolerance test (OGTT) depending on the center. All OGTT results were reviewed. Women with glycemic values falling between the thresholds of the two tests, referred to as intermediate hyperglycemic (IH), defined as FPG 5.1-5.2 mmol/L, 1 h PG 10.0-10.5 mmol/L, or 2 h PG 8.5-8.9 mmol/L at 75 g OGTT, were untreated at center A and treated at center B.

RESULTS

There were 630 women with IH, 334 were untreated (center A) and 296 who were treated (center B). After adjusting for covariates, untreated IH women had significantly higher rates of gestational hypertension (aOR 6.02, P = 0.002), large for gestational age (LGA) (aOR 3.73, P < 0.001) and birthweights > 4000 g (aOR 3.35, P = 0.001). Our results indicate that treating 11 women with IH would prevent one LGA birth and treating 13 would prevent 1 birthweight > 4000 g.

CONCLUSION

The diagnosis of GDM using the two-step OGTT fails to identify subgroups of women with mild hyperglycemia that would benefit from treatment to lower the risk for adverse maternal and neonatal outcomes. Treatment of women with mild hyperglycemia decreased the risk of LGA and birthweight >4000 g by 3-fold.

Benefits and harms associated with an increase in gestational diabetes diagnosis in Queensland, Australia: a retrospective cohort comparison of diagnosis rates, outcomes, interventions and medication use for two periods, 2011-2013 and 2016-2018, using a large perinatal database

OBJECTIVES

To assess benefits and harms arising from increasing gestational diabetes (GDM) diagnosis, including for women with normal-sized babies.

DESIGN, SETTING AND PARTICIPANTS

Diagnosis rates, outcomes, interventions and medication use are compared in a retrospective cohort study of 229 757 women birthing in public hospitals of the Australian State of Queensland during two periods, 2011-2013 and 2016-2018, using data from the Queensland Perinatal Data Collection.

OUTCOME MEASURES

Comparisons include hypertensive disorders, caesarean section, shoulder dystocia and associated harm, induction of labour (IOL), planned birth (PB), early planned birth <39 weeks (EPB), spontaneous labour onset with vaginal birth (SLVB) and medication use.

RESULTS

GDM diagnosis increased from 7.8% to 14.3%. There was no improvement in shoulder dystocia associated injuries, hypertensive disorders or caesarean sections. There was an increase in IOL (21.8%-30.0%; p<0.001), PB (36.3% to 46.0%; p<0.001) and EPB (13.5%-20.6%; p<0.001), and a decrease in SLVB (56.0%-47.3%; p<0.001). Women with GDM experienced an increase in IOL (40.9%-49.8%; p<0.001), PB (62.9% to 71.8%; p<0.001) and EPB (35.3%-45.7%; p<0.001), and a decrease in SLVB (30.01%-23.6%; p<0.001), with similar changes for mothers with normal-sized babies. Of women prescribed insulin in 2016-2018, 60.4% experienced IOL, 88.5% PB, 76.4% EPB and 8.0% SLVB. Medication use increased from 41.2% to 49.4% in women with GDM, from 3.2% to 7.1% in the antenatal population overall, from 3.3% to 7.5% in women with normal-sized babies and from 2.21% to 4.38% with babies less than the 10th percentile.

CONCLUSION

Outcomes were not apparently improved with increased GDM diagnosis. The merits of increased IOL or decreased SLVB depend on the views of individual women, but categorising more pregnancies as abnormal, and exposing more babies to the potential effects of early birth, medication effects and growth limitation may be harmful.

Mid-pregnancy sleep disturbances are not associated with mid-pregnancy maternal glycemia

Background

In pregnancy, epidemiological data have consistently shown strong associations between sleep quality and duration and maternal glycemia. However, other sleep disturbances such as difficulty falling asleep and staying asleep are common in pregnancy. They may contribute to impaired maternal glycemia through sympathetic nervous system activity, systemic inflammation, and hormonal pathways. However, there is little research examining associations between these specific sleep disturbances and maternal glycemia.

Objective

This study aimed to investigate the associations of sleep disturbances during mid-pregnancy and mid-pregnancy maternal glycemia and gestational diabetes subtypes.

Study Design

This is a secondary data analysis of the Comparison of Two Screening Strategies for Gestational Diabetes trial. Participants (n = 828) self-reported the frequency of sleep disturbances (i.e., trouble falling asleep, trouble staying asleep, waking several times per night, and waking feeling tired or worn out) in mid-pregnancy. Gestational diabetes was diagnosed using either the International Associations of Diabetes and Pregnancy Study Groups or Carpenter-Coustan approach. We defined gestational diabetes subtypes based on the degree of insulin resistance and beta-cell dysfunction. We used multinomial logistic regression to examine associations of sleep disturbances with gestational diabetes status (i.e., normal, mild glycemic dysfunction, and gestational diabetes) and gestational diabetes subtypes (i.e., neither insulin resistance or beta-cell dysfunction, insulin resistance only, beta-cell dysfunction only, and insulin resistance and beta-cell dysfunction).

Results

A total of 665 participants (80%) had normal glycemia, 81 (10%) mild hyperglycemia, and 80 (10%) had gestational diabetes. Among participants with gestational diabetes, 62 (78%) had both insulin resistance and beta-cell dysfunction, 15 (19 %) had insulin resistance only, and 3 had beta-cell dysfunction only or neither insulin resistance nor beta-cell dysfunction. Sleep disturbance frequency was not associated with maternal glycemia or gestational diabetes subtypes.

Conclusions

Sleep disturbances in mid-pregnancy were not associated with maternal glycemia during mid-pregnancy. Future research should collect data on sleep disturbances at multiple time points in pregnancy and in combination with other sleep disturbances to determine whether sleep plays any role in maternal glycemic control.

Effect of Tinospora cordifolia on gestational diabetes mellitus and its complications

Ayurvedic system of medicine uses giloy or guduchi, also known as Tinospora cordifolia (TC), to treat diabetes and related diseases like hyperglycemia and hyperlipididemia. However, its usage in gestational diabetes mellitus (GDM) is not well studied. The primary objective of the study was to examine the effects of water extract of TC called satva, essential oil, and hydroalcoholic (HA) extract on GDM and its complications and to explore their mechanism of action using mice model. We used streptozotocin-induced diabetes in pregnant mice as murine model and tested TC preparations for anti-GDM activities. Blood glucose, insulin, litter size, and placental weight were assessed. ELISA method was used to measure plasma insulin level to compute homeostatic model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and homeostatic model assessment for assessing beta cell function (HOMA-Beta) levels to estimate insulin resistance, insulin sensitivity, and beta cell function respectively. TC-treated groups had significantly higher serum insulin levels, QUICKI, average litter size, and lower placental weight (p < .001). TC oil and HA extract increased pancreatic beta cell activity according to the level of HOMA-Beta. TC lowered placenta weight and increased litter size significantly compared to control group. Our findings suggest that TC preparations preserve pancreatic beta cells, increase insulin production, decrease insulin resistance, and improve beta cell function, hence preventing GDM. TC preparations also reduced placental weight and increased litter size in mice. Based on these results, we recommend the clinical trial and testing of TC preparations for management of GDM and associated complications. Refer graphical abstract (Figure S1).

Clinicians' perspectives on gestational diabetes screening during the global COVID-19 pandemic in Australia

AIM

There is no international consensus for the screening and diagnosis of gestational diabetes mellitus (GDM). In March 2020, modified screening and diagnostic recommendations were rapidly implemented in Queensland, Australia, in response to the COVID-19 pandemic. How clinicians perceived and used these changes can provide insights to support high-quality clinical practice and provide lessons for future policy changes. The aim of this study was to understand clinicians' perceptions and use of COVID-19 changes to GDM screening and diagnostic recommendations.

METHODS

Queensland healthcare professionals responsible for diagnosing or caring for women with GDM were recruited for semi-structured telephone interviews. Data analysis of transcribed interviews used inductive reflexive thematic analysis.

RESULTS

Seventeen interviews were conducted with the following participants: six midwives/nurses, three endocrinologists, two general practitioners, two general practitioners/obstetricians, two diabetes educators, one dietitian and one obstetrician. Three themes emerged: communication and implementation, perceptions and value of evidence and diversity in perceptions of GDM screening. Overall, clinicians welcomed the rapid changes during the initial uncertainty of the pandemic, but as COVID-19 became less of a threat to the Queensland healthcare system, some questioned the underlying evidence base. In areas where GDM was more prevalent, clinicians more frequently worried about missed diagnoses, whereas others who felt that overdiagnosis had occurred in the past continued to support the changes.

CONCLUSIONS

These findings highlight the challenges to changing policy when clinicians have diverse (and often strongly held) views.

Stress, social support, and racial differences: Dominant drivers of exclusive breastfeeding

Exclusive breastfeeding is recommended for 6 months; however, many childbearing people wean their infants before 6 months. Psychosocial factors such as stress, social support and race are significant determinants of breastfeeding; however, few studies have longitudinally explored the effect of perceived stress and various forms of social support on exclusive breastfeeding. We used quantitative methodologies to examine exclusive breastfeeding, perceived stress and social support among 251 participants from the Postpartum Mothers Mobile Study. Participants between 18 and 44 years were recruited during pregnancy (irrespective of parity) and completed surveys in real-time via Ecological Momentary Assessment up to 12 months postpartum from December 2017 to August 2021. We measured perceived stress with the adapted Perceived Stress Scale and perceived social support with the Multi-dimensional Social Support Scale. Received social support was measured using a single question on breastfeeding support. We conducted a mixed-effects logistic regression to determine the effect of stress, race and social support on exclusive breastfeeding over 6 months. We examined the moderation effect of perceived social support and breastfeeding support in the relationship between perceived stress and exclusive breastfeeding. Black, compared with White, participants were less likely to breastfeed exclusively for 6 months. Participants who reported higher perceived stress were less likely to breastfeed exclusively for 6 months. Perceived social support moderated the relationship between perceived stress and exclusive breastfeeding (odds ratio: 0.01, 95% confidence interval: 0.001-0.072). However, breastfeeding support directly increased the likelihood of exclusive breastfeeding over 6 months. Perceived stress is negatively associated with exclusive breastfeeding. Birthing people who intend to breastfeed may benefit from perinatal support programs that include components to buffer stress.

Ray J, Geary M, Murray‐Davis B. Exploring patients' perspectives of gestational diabetes mellitus screening and counselling in Ontario: A grounded theory study

INTRODUCTION

Gestational diabetes mellitus (GDM) is associated with adverse perinatal outcomes. Approaches to screening for GDM continue to evolve, introducing potential variability of care. This study explored the impact of these variations on GDM counselling and screening from the perspectives of pregnant individuals.

METHODS

Following a Corbin and Strauss approach to qualitative, grounded theory we recruited 28 individuals from three cities in Ontario, Canada who had a singleton pregnancy under the care of either a midwife, family physician or obstetrician. Convenience and purposive sampling techniques were used. Semi-structured telephone interviews were conducted and transcribed verbatim between March and December 2020. Transcripts were analysed inductively resulting in codes, categories and themes.

RESULTS

Three themes were derived from the data about GDM screening and counselling: 'informing oneself', 'deciding' and 'screening'. All participants, regardless of geographical region, or antenatal care provider, moved through these three steps during the GDM counselling and screening process. Differences in counselling approaches between pregnancy care providers were noted throughout the 'informing' and 'deciding' stages of care. Factors influencing these differences included communication, healthcare autonomy and patient motivation to engage with health services. No differences were noted within care provider groups across the three geographic regions. Participant experiences of GDM screening were influenced by logistical challenges and personal preferences towards testing.

CONCLUSION

Informing oneself about GDM may be a crucial step for facilitating decision-making and screening uptake, with an emphasis on information provision to facilitate patient autonomy and motivation.

PATIENT OR PUBLIC CONTRIBUTION

Participants of our study included patients and service users. Participants were actively involved in the study design due to the qualitative, patient-centred nature of the research methods employed. Analysis of results was structured according to the emergent themes of the data which were grounded in patient perspectives and experiences.

The effect of changing screening practices and demographics on the incidence of gestational diabetes in British Columbia, 2005-2019

BACKGROUND

Rates of gestational diabetes are reported to be increasing in many jurisdictions, but the reasons for this are poorly understood. We sought to evaluate the relative contribution of screening practices for gestational diabetes (including completion and methods of screening) and population characteristics to risk of gestational diabetes in British Columbia, Canada, from 2005 to 2019.

METHODS

We used a population-based cohort from a provincial registry of perinatal data, linked to laboratory billing records. We used data on screening completion, screening method (1-step 75-g glucose test or 2-step approach of 50-g glucose screening test, followed by a diagnostic test for patients who screen positive) and demographic risk factors. We modelled predicted annual risk for gestational diabetes, sequentially adjusted for screening completion, screening method and risk factors.

RESULTS

We included 551 457 pregnancies in the study cohort. The incidence of gestational diabetes more than doubled over the study period, from 7.2% in 2005 to 14.7% in 2019. Screening completion increased from 87.2% in 2005 to 95.5% in 2019. Use of 1-step screening methods increased from 0.0% in 2005 to 39.5% in 2019 among those who were screened. Unadjusted models estimated a 2.04 (95% confidence interval [CI] 1.94-2.13) increased risk of gestational diabetes in 2019 (v. 2005). This increase was 1.89 (95% CI 1.81-1.98) after accounting for the rise in screening completion and 1.34 (95% CI 1.28-1.40) after accounting for changes in screening methods. Further accounting for demographic risk factors (e.g., age, body mass index, prenatal care) had a small impact (increase of 1.25, 95% CI 1.19-1.31).

INTERPRETATION

Most of the observed increase in the incidence of gestational diabetes was attributable to changes in screening practices (primarily changes in screening methods) rather than changing population factors. Our findings highlight the importance of understanding variation in screening practices when monitoring incidence rates for gestational diabetes.

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.

One-Step Compared With Two-Step Gestational Diabetes Screening and Pregnancy Outcomes: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate short-term maternal and neonatal outcomes with one-compared with two-step testing for gestational diabetes mellitus (GDM).

DATA SOURCES

A systematic review of randomized controlled trials (RCTs) and observational studies comparing one-step and two-step GDM testing strategies before September 2021 was conducted. We searched Ovid Medline (1946-), EMBASE (1947-), Scopus (1960-), Cochrane Central, and ClinicalTrials.gov . The primary outcome was rate of large-for-gestational age (LGA) neonates. Secondary outcomes were clinically relevant outcomes for GDM that were selected a priori.

METHODS OF STUDY SELECTION

Titles, abstracts, and manuscripts were screened, selected, and reviewed by the first two authors. Four RCTs (24,966 patients) and 13 observational studies (710,677 patients) were analyzed.

TABULATION, INTEGRATION, AND RESULTS

Pooled relative risks (RRs) were calculated with 95% CIs using random-effects models and were plotted graphically with forest plots. Study heterogeneity was evaluated using Cochran Q and Higgins I 2 tests. The quality of studies that met the inclusion criteria was evaluated with the Downs and Black checklist. Publication bias was assessed by using asymmetry of funnel plots and Harbord's test. There was no difference in the rate of LGA neonates (pooled RR 0.95; 95% CI 0.88-1.04) by testing strategy among RCTs, but patients who underwent one-step testing were more likely to be diagnosed with GDM (pooled RR 2.13; 95% CI 1.61-2.82) and treated with diabetes medications (pooled RR 2.24; 95% CI 1.21-4.15). One-step testing was associated with higher rates of neonatal intensive care unit (NICU) admission (pooled RR 1.12; 95% CI 1.00-1.26) and neonatal hypoglycemia (pooled RR 1.23; 95% CI 1.13-1.34). In analysis of high-quality RCTs and observational studies, one-step testing was associated with a lower rate of LGA neonates (pooled RR 0.97; 95% CI 0.95-0.98), but higher rates of GDM diagnosis, treatment, NICU admission, and neonatal hypoglycemia.

CONCLUSION

Despite a significant increase in GDM diagnosis and treatment with one-step testing, there is no difference in rate of LGA neonates compared with two-step testing among RCTs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021252703.

Fetoplacental oxygen homeostasis in pregnancies with maternal diabetes mellitus and obesity

Despite improvements in clinical management, pregnancies complicated by pre-existing diabetes mellitus, gestational diabetes mellitus or obesity carry substantial risks for parent and offspring. Some of the endocrine and metabolic changes in parent and fetus in diabetes mellitus and obesity lead to fetal oxygen deficit, mostly due to insulin-induced accelerated fetal metabolism. The human fetus deals with reduced oxygenation through a wide range of adaptive responses that act at various levels in the placenta as well as the fetus. These responses ensure adequate oxygen delivery to the fetus, increase the oxygen transport capacity of fetal blood and redistribute oxygen-rich blood to vital organs such as the brain and heart. The liver has a central role in adapting to reduced oxygenation by increasing its oxygen extraction and stimulating erythropoietin synthesis to increase haematocrit. The type of adaptive response depends on the onset and duration of hypoxia and the severity of the metabolic disturbance. In pregnancies characterized by diabetes mellitus or obesity, these adaptive systems come under additional strain owing to the increased maternal supply of glucose and resultant fetal hyperinsulinaemia, both of which stimulate oxidative metabolism. In the rare situation that the adaptive responses are overwhelmed, stillbirth can ensue.

Lower versus Higher Glycemic Criteria for Diagnosis of Gestational Diabetes

BACKGROUND

Treatment of gestational diabetes improves maternal and infant health, although diagnostic criteria remain unclear.

METHODS

We randomly assigned women at 24 to 32 weeks' gestation in a 1:1 ratio to be evaluated for gestational diabetes with the use of lower or higher glycemic criteria for diagnosis. The lower glycemic criterion was a fasting plasma glucose level of at least 92 mg per deciliter (≥5.1 mmol per liter), a 1-hour level of at least 180 mg per deciliter (≥10.0 mmol per liter), or a 2-hour level of at least 153 mg per deciliter (≥8.5 mmol per liter). The higher glycemic criterion was a fasting plasma glucose level of at least 99 mg per deciliter (≥5.5 mmol per liter) or a 2-hour level of at least 162 mg per deciliter (≥9.0 mmol per liter). The primary outcome was the birth of an infant who was large for gestational age (defined as a birth weight above the 90th percentile according to Fenton-World Health Organization standards). Secondary outcomes were maternal and infant health.

RESULTS

A total of 4061 women underwent randomization. Gestational diabetes was diagnosed in 310 of 2022 women (15.3%) in the lower-glycemic-criteria group and in 124 of 2039 women (6.1%) in the higher-glycemic-criteria group. Among 2019 infants born to women in the lower-glycemic-criteria group, 178 (8.8%) were large for gestational age, and among 2031 infants born to women in the higher-glycemic-criteria group, 181 (8.9%) were large for gestational age (adjusted relative risk, 0.98; 95% confidence interval, 0.80 to 1.19; P = 0.82). Induction of labor, use of health services, use of pharmacologic agents, and neonatal hypoglycemia were more common in the lower-glycemic-criteria group than in the higher-glycemic-criteria group. The results for the other secondary outcomes were similar in the two trial groups, and there were no substantial between-group differences in adverse events. Among the women in both groups who had glucose test results that fell between the lower and higher glycemic criteria, those who were treated for gestational diabetes (195 women), as compared with those who were not (178 women), had maternal and infant health benefits, including fewer large-for-gestational-age infants.

CONCLUSIONS

The use of lower glycemic criteria for the diagnosis of gestational diabetes did not result in a lower risk of a large-for-gestational-age infant than the use of higher glycemic criteria. (Funded by the Health Research Council of New Zealand and others; GEMS Australian New Zealand Clinical Trials Registry number, ACTRN12615000290594.).

The Diagnostic Accuracy of Second Trimester Plasma Glycated CD59 (pGCD59) to Identify Women with Gestational Diabetes Mellitus Based on the 75 g OGTT Using the WHO Criteria: A Prospective Study of Non-Diabetic Pregnant Women in Ireland

The aim of this study was to evaluate the ability of second trimester plasma glycated CD59 (pGCD59), a novel biomarker, to predict the results of the 2 h 75 g oral glucose tolerance test at 24−28 weeks of gestation, employing the 2013 World Health Organisation criteria. This was a prospective study of 378 pregnant women. The ability of pGCD59 to predict gestational diabetes (GDM) was assessed using adjusted ROC curves for maternal age, BMI, maternal ethnicity, parity, previous GDM, and family history of diabetes. The pGCD59 levels were significantly higher in women with GDM compared to women with normal glucose tolerance (p = 0.003). The pGCD59 generated an adjusted AUC for identifying GDM cases of 0.65 (95%CI: 0.58−0.71, p < 0.001). The pGCD59 predicted GDM status diagnosed by a fasting glucose value of 5.1 mmol/L with an adjusted AUC of 0.74 (95%CI: 0.65−0.81, p < 0.001). Analysis of BMI subgroups determined that pGCD59 generated the highest AUC in the 35 kg/m2 ≤ BMI < 40 kg/m2 (AUC: 0.84 95%CI: 0.69−0.98) and BMI ≥ 40 kg/m2 (AUC: 0.96 95%CI: 0.86−0.99) categories. This study found that second trimester pGCD59 is a fair predictor of GDM status diagnosed by elevated fasting glucose independent of BMI and an excellent predictor of GDM in subjects with a very high BMI.

Diabetes und Schwangerschaft – Update 2022

Gestationsdiabetes mellitus (GDM) ist mit einem Anteil von 80 % die häufigste Form der Hyperglykämie in der Schwangerschaft. Stillen reduziert das Risiko für Typ-2-Diabetes, je länger die Stilldauer, umso größer ist der Effekt. Bei Frauen, die eine Früh- oder eine Totgeburt durchgemacht haben, besteht ein erhöhtes Risiko, selbst frühzeitig zu versterben. Das Potenzial einer Präeklampsieprävention durch niedrig dosierte Azetylsalizylsäuregabe bei Frauen mit Diabetes mellitus wird bei weitem nicht ausgeschöpft. Schwangere reduzieren durch eine COVID-19-Impfung (COVID-19: „coronavirus disease 2019“) ihr Risiko für einen schweren Krankheitsverlauf. Die nach wie vor hohe Rate an perinataler Mortalität bei Schwangerschaften mit Typ-1- und Typ-2-Diabetes kann in erster Linie durch eine Verbesserung von Basisfaktoren bei der perikonzeptionellen Betreuung reduziert werden. Zweizeitiges Screening auf GDM reduziert im Vergleich zum einzeitigen Screening die GDM-Prävalenz und die Medikalisierung ohne Nachteile für die Mütter und ihre Neugeborenen. Die Zulassung von Metformin für Schwangere seit Februar 2022 bedeutet nicht, dass dieses Arzneimittel als primäre Pharmakotherapie für schwangere Frauen empfohlen wird.

A Cluster Randomized Noninferiority Field Trial of Gestational Diabetes Mellitus Screening

CONTEXT

Although it is well-acknowledged that gestational diabetes mellitus (GDM) is associated with the increased risks of adverse pregnancy outcomes, the optimal strategy for screening and diagnosis of GDM is still a matter of debate.

OBJECTIVE

This study was conducted to demonstrate the noninferiority of less strict GDM screening criteria compared with the strict International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria with respect to maternal and neonatal outcomes.

METHODS

A cluster randomized noninferiority field trial was conducted on 35 528 pregnant women; they were scheduled to have 2 phases of GDM screening based on 5 different prespecified protocols including fasting plasma glucose in the first trimester with threshold of 5.1 mmol/L (92 mg/dL) (protocols A, D) or 5.6 mmol/L (100 mg/dL) (protocols B, C, E) and either a 1-step (GDM is defined if one of the plasma glucose values is exceeded [protocol A and C] or 2 or more exceeded values are needed [protocol B]) or 2-step approach (protocols D, E) in the second trimester. Guidelines for treatment of GDM were consistent with all protocols. Primary outcomes of the study were the prevalence of macrosomia and primary cesarean section (CS). The null hypothesis that less strict protocols are inferior to protocol A (IADPSG) was tested with a noninferiority margin effect (odds ratio) of 1.7.

RESULTS

The percentages of pregnant women diagnosed with GDM and assigned to protocols A, B, C, D, and E were 21.9%, 10.5%, 12.1%, 19.4%, and 8.1%, respectively. Intention-to-treat analyses satisfying the noninferiority of the less strict protocols of B, C, D, and E compared with protocol A. However, noninferiority was not shown for primary CS comparing protocol E with A. The odds ratios (95% CI) for macrosomia and CS were: B (1.01 [0.95-1.08]; 0.85 [0.56-1.28], C (1.03 [0.73-1.47]; 1.16 [0.88-1.51]), D (0.89 [0.68-1.17]; 0.94 [0.61-1.44]), and E (1.05 [0.65-1.69]; 1.33 [0.82-2.00]) vs A. There were no statistically significant differences in the adjusted odds of adverse pregnancy outcomes in the 2-step compared with the 1-step screening approaches, considering multiplicity adjustment.

CONCLUSIONS

The IADPSG GDM definition significantly increased the prevalence of GDM diagnosis. However, the less strict approaches were not inferior to other criteria in terms of adverse maternal and neonatal outcomes.

Screening auf Gestationsdiabetes mellitus (GDM) – Welchen Weg weisen die neuen Studien? Übersicht und Kommentar

Das Screening auf Gestationsdiabetes mellitus (GDM) wird international nicht einheitlich durchgeführt. In Deutschland wird allen Schwangeren ein zweizeitiges Screening angeboten, zunächst ein 50-g Vortest (nicht nüchtern), im positiven Fall gefolgt von einem 75-g oralen Gluksetoleranztest (oGTT) über 2 h (nüchtern). Im Jahr 2021 sind zwei randomisierte Screeningstudien publiziert worden, in denen einzeitiges Screenen ohne Vortest mit dem zweizeitigen Screenen verglichen wurde. Einzeitiges Screenen erhöht die GDM-Prävalenz um das 2,3-fache ohne Vorteile für klinisch relevante Endpunkte von Müttern und Neugeborenen und um den Preis unnötiger Pharmakotherapie sowie Belastung der Ressourcen bei den Betreuern. Beim zweizeitigen Screening benötigen nur 20% der Frauen einen oGTT. Darüber hinaus wird die zweizeitige Strategie von den Frauen präferiert.

Gestational diabetes mellitus and COVID-19: results from the COVID-19-Related Obstetric and Neonatal Outcome Study (CRONOS)

Background

Gestational diabetes mellitus is one of the most frequent pregnancy complications with a global prevalence of 13.4% in 2021. Pregnant women with COVID-19 and gestational diabetes mellitus are 3.3 times more likely to be admitted to an intensive care unit than women without gestational diabetes mellitus. Data on the association of gestational diabetes mellitus with maternal and neonatal pregnancy outcomes in pregnant women with SARS-CoV-2 infection are lacking.

Objective

This study aimed to investigate whether gestational diabetes mellitus is an independent risk factor for adverse maternal and fetal and neonatal outcomes in pregnant women with COVID-19.

Study Design

The COVID-19-Related Obstetric and Neonatal Outcome Study is a registry-based multicentric prospective observational study from Germany and Linz, Austria. Pregnant women with clinically confirmed COVID-19 were enrolled between April 3, 2020, and August 24, 2021, at any stage of pregnancy. Obstetricians and neonatologists of 115 hospitals actively provided data to the COVID-19-Related Obstetric and Neonatal Outcome Study. For collecting data, a cloud-based electronic data platform was developed. Women and neonates were observed until hospital discharge. Information on demographic characteristics, comorbidities, medical history, COVID-19–associated symptoms and treatments, pregnancy, and birth outcomes were entered by the local sites. Information on the periconceptional body mass index was collected. A primary combined maternal endpoint was defined as (1) admission to an intensive care unit (including maternal mortality), (2) viral pneumonia, and/or (3) oxygen supplementation. A primary combined fetal and neonatal endpoint was defined as (1) stillbirth at ≥24 0/7 weeks of gestation, (2) neonatal death ≤7 days after delivery, and/or (3) transfer to a neonatal intensive care unit. Multivariable logistic regression analysis was performed to evaluate the modulating effect of gestational diabetes mellitus on the defined endpoints.

Results

Of the 1490 women with COVID-19 (mean age, 31.0±5.2 years; 40.7% nulliparous), 140 (9.4%) were diagnosed with gestational diabetes mellitus; of these, 42.9% were treated with insulin. Overall, gestational diabetes mellitus was not associated with an adverse maternal outcome (odds ratio, 1.50; 95% confidence interval, 0.88–2.57). However, in women who were overweight or obese, gestational diabetes mellitus was independently associated with the primary maternal outcome (adjusted odds ratio, 2.69; 95% confidence interval, 1.43–5.07). Women who were overweight or obese with gestational diabetes mellitus requiring insulin treatment were found to have an increased risk of a severe course of COVID-19 (adjusted odds ratio, 3.05; 95% confidence interval, 1.38–6.73). Adverse maternal outcomes were more common when COVID-19 was diagnosed with or shortly after gestational diabetes mellitus diagnosis than COVID-19 diagnosis before gestational diabetes mellitus diagnosis (19.6% vs 5.6%; P<.05). Maternal gestational diabetes mellitus and maternal preconception body mass index of ≥25 kg/m² increased the risk of adverse fetal and neonatal outcomes (adjusted odds ratio, 1.83; 95% confidence interval, 1.05–3.18). Furthermore, overweight and obesity (irrespective of gestational diabetes mellitus status) were influential factors for the maternal (adjusted odds ratio, 1.87; 95% confidence interval, 1.26–2.75) and neonatal (adjusted odds ratio, 1.81; 95% confidence interval, 1.32–2.48) primary endpoints compared with underweight or normal weight.

Conclusion

Gestational diabetes mellitus, combined with periconceptional overweight or obesity, was independently associated with a severe maternal course of COVID-19, especially when the mother required insulin and COVID-19 was diagnosed with or after gestational diabetes mellitus diagnosis. These combined factors exhibited a moderate effect on neonatal outcomes. Women with gestational diabetes mellitus and a body mass index of ≥25 kg/m² were a particularly vulnerable group in the case of COVID-19.

One-step versus two-step screening for diagnosis of gestational diabetes mellitus in Iranian population: A randomized community trial

OBJECTIVES

There is considerable worldwide controversy regarding optimal screening and diagnostic approaches for GDM. This study aimed to compare the prevalence, maternal and neonatal outcomes of a One-step with a Two-step approach for the screening and diagnosis of GDM in a large community sample of pregnant women.

METHODS

We conducted a secondary analysis of a randomized community non-inferiority trial of GDM screening in Iran. For the current study, all pregnant women who met the inclusion criteria were randomized into two groups for GDM screening. The first group of women (n = 14611) was screened by a One-step screening approach [75-g 2-h oral glucose tolerance test (OGTT)] and the second group (n = 14160) by a Two-step method (the 50-g glucose challenge test followed by the 100-g OGTT). All study participants were followed up until delivery, and the adverse maternal and neonatal outcomes were recorded in detail.

RESULTS

GDM was diagnosed in 9.3% of the pregnant women who were assigned to the One-step and in 5.4% of those assigned to the Two-step approach with a statistically significant difference between them (p < 0.001). Intention-to-treat analyses showed no significant differences between the One-step and the Two-step group in the unadjusted risks of the adverse pregnancy outcomes of macrosomia, primary cesarean-section, preterm birth, hypoglycemia, hypocalcemia, hyperbilirubinemia, preeclampsia, neonatal intensive care unit admission, birth trauma, low birth weight, and intrauterine fetal death. Results remained unchanged after adjustment for potential confounder variables including gestational age at enrollment and delivery, maternal body mass index, gestational weight gain, type of delivery, treatment modality, and GDM diagnosis in the first trimester.

CONCLUSION

We found that although the rates of GDM more than doubled with the One-step strategy, the One-step approach was similar to the Two-step approach in terms of maternal and neonatal outcomes. These findings may warn that more caution should be exercised in adopting the One-step method worldwide. Future research is needed to assess the long-term harm and benefits of those approaches to GDM screening for both mothers and their offspring.

CLINICAL TRIAL REGISTRATION

https://www.irct.ir/trial/518, identifier (IRCT138707081281N1).

Gestational Diabetes Mellitus: Diagnostic Approaches and Maternal-Offspring Complications

Gestational diabetes mellitus (GDM) is the most common complication during pregnancy and is defined as any degree of glucose intolerance with onset or first recognition during pregnancy. GDM is associated with adverse pregnancy outcomes and long-term offspring and maternal complications. For GDM screening and diagnosis, a two-step approach (1-hour 50 g glucose challenge test followed by 3-hour 100 g oral glucose tolerance test) has been widely used. After the Hyperglycemia and Adverse Pregnancy Outcome study implemented a 75 g oral glucose tolerance test in all pregnant women, a one-step approach was recommended as an option for the diagnosis of GDM after 2010. The one-step approach has more than doubled the incidence of GDM, but its clinical benefit in reducing adverse pregnancy outcomes remains controversial. Long-term complications of mothers with GDM include type 2 diabetes mellitus and cardiovascular disease, and complications of their offspring include childhood obesity and glucose intolerance. The diagnostic criteria of GDM should properly classify women at risk for adverse pregnancy outcomes and long-term complications. The present review summarizes the strengths and weaknesses of the one-step and two-step approaches for the diagnosis of GDM based on recent randomized controlled trials and observational studies. We also describe the long-term maternal and offspring complications of GDM.

Trends in Stress Throughout Pregnancy and Postpartum Period During the COVID-19 Pandemic: Longitudinal Study Using Ecological Momentary Assessment and Data From the Postpartum Mothers Mobile Study

BACKGROUND

Stress is associated with adverse birth and postpartum health outcomes. Few studies have longitudinally explored racial differences in maternal stress in a birthing population in the United States during the ongoing COVID-19 pandemic.

OBJECTIVE

This study aimed to do the following: (1) assess changes in reported stress before, during, and after initial emergency declarations (eg, stay-at-home orders) were in place due to the COVID-19 pandemic, and (2) assess Black-White differences in reported stress in a pregnant and postpartum population from Southwestern Pennsylvania.

METHODS

We leveraged data from the ongoing Postpartum Mothers Mobile Study (PMOMS), which surveys participants in real time throughout the pregnancy and postpartum periods via ecological momentary assessment (EMA) and smartphone technology. We analyzed data from a subset of PMOMS participants (n=85) who were either Black or White, and who submitted EMA responses regarding stress between November 1, 2019, and August 31, 2020, the time frame of this study. We divided data into four phases based on significant events during the COVID-19 pandemic: "pre" phase (baseline), "early" phase (first case of COVID-19 reported in United States), "during" phase (stay-at-home orders), and "post" phase (stay-at-home orders eased). We assessed mean stress levels at each phase using linear mixed-effects models and post hoc contrasts based on the models.

RESULTS

Overall mean stress (0=not at all to 4=a lot) during the pre phase was 0.8 for Black and White participants (range for Black participants: 0-3.9; range for White participants: 0-2.8). There was an increase of 0.3 points (t5649=5.2, P<.001) in the during phase as compared with the pre phase, and an increase of 0.2 points (t5649=3.1, P=.002) in the post phase compared with the pre phase (n=85). No difference was found between Black and White participants in the change in mean stress from the pre phase to the during phase (overall change predicted for the regression coefficient=-0.02, P=.87). There was a significant difference between Black and White participants in the change in mean stress from the during phase to the post phase (overall change predicted for the regression coefficient=0.4, P<.001).

CONCLUSIONS

There was an overall increase in mean stress levels in this subset of pregnant and postpartum participants during the same time as the emergency declarations/stay-at-home orders in the United States. Compared to baseline, mean stress levels remained elevated when stay-at-home orders eased. We found no significant difference in the mean stress levels by race. Given that stress is associated with adverse birth outcomes and postpartum health, stress induced by the ongoing COVID-19 pandemic may have adverse implications for birthing populations in the United States.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/13569.