Prevalence of gestational diabetes among Chinese and South Asians: A Canadian population-based analysis

Maternal and Fetal Outcomes in Pregnancy in the Fifth Decade of Life and Beyond

OBJECTIVES

The objective is to evaluate maternal and fetal outcomes at an extremely advanced maternal age (AMA) (over age 50 years) in Calgary. The secondary objective is to determine if there is a role in protocolizing complex care plans for patients at extreme AMAs.

METHODS

A retrospective chart review was conducted of all pregnancies ≥20 weeks gestation in patients over the age of 50 years that delivered in Calgary between January 2007 and December 2021. Pregnancy data were collected, including maternal age, pre-existing medical conditions, mode and timing of delivery, neonatal outcomes, neonatal intensive care unit (NICU) and adult intensive care unit (ICU) admissions, postpartum complications, and maternal or neonatal death. Data were extracted for maternity patients as well as neonatal ICU databases. Maternal and neonatal outcomes were assessed until discharge from hospital.

RESULTS

All 23 pregnancies identified were achieved through assisted reproductive technologies. Comorbidities varied, but the most common comorbidities included hypertension and gestational diabetes. Cesarean delivery was the most common form of delivery. Three cases involved postpartum maternal ICU admission. Neonatal outcomes included gestational ages of 22-39 weeks and birth weights of 486-3593 g, with 8 confirmed NICU admissions. The most common neonatal complications were jaundice and small for gestational age.

CONCLUSIONS

Extremely AMA patients are more likely to have pre-existing comorbidities and develop comorbidities during pregnancy. The potential for adverse maternal and fetal outcomes is greater for these pregnancies; however, the complications are diverse and developing a universal complex care plan is difficult.

Diabetes mellitus in pregnancy across Canada

BACKGROUND

Contemporary estimates of diabetes mellitus (DM) rates in pregnancy are lacking in Canada. Accordingly, this study examined trends in the rates of type 1 (T1DM), type 2 (T2DM) and gestational (GDM) DM in Canada over a 15-year period, and selected adverse pregnancy outcomes.

METHODS

This study used repeated cross-sectional data from the Canadian Institute of Health Information (CIHI) hospitalization discharge abstract database (DAD). Maternal delivery records were linked to their respective birth records from 2006 to 2019. The prevalence of T1DM, T2DM and GDM were calculated, including relative changes over time, assessed by a Cochrane-Armitage test. Also assessed were differences between provinces and territories in the prevalence of DM.

RESULTS

Over the 15-year study period, comprising 4,320,778 hospital deliveries in Canada, there was a statistically significant increase in the prevalence of GDM and T1DM and T2DM. Compared to pregnancies without DM, all pregnancies with any form of DM had higher rates of hypertension and Caesarian delivery, and also adverse infant outcomes, including major congenital anomalies, preterm birth and large-for-gestational age birthweight.

CONCLUSION

Among 4.3 million pregnancies in Canada, there has been a rise in the prevalence of DM. T2DM and GDM are expected to increase further as more overweight women conceive in Canada.

Prevalence of gestational diabetes in the United States and Canada: a systematic review and meta-analysis

BACKGROUND

An understanding of the prevalence of gestational diabetes mellitus among pregnant women is essential at local, national and international level so that appropriate health care interventions can be planned, financed and delivered.

METHODS

A systematic review and meta-analysis of primary research reporting the prevalence of gestational diabetes mellitus in Canada or the United States were carried out according to Meta-analysis of Observational Studies in Epidemiology guidelines. Four electronic databases were systematically searched in June 2023 to identify articles that reported gestational diabetes mellitus prevalence using universal screening in pregnant women from eligible general population samples. Estimates were combined using a random effects model, and the effects of moderator variables analysed.

RESULTS

There were 36 separate samples of women or deliveries (total sample size 1,550,917). Overall mean prevalence of gestational diabetes mellitus was 6.9% (95% CI: 5.7-8.3); 13.7% (95% CI: 10.7-17.3) in studies using a one-step screening strategy, and 5.2% (95% CI: 4.4-6.1) in those using a two-step strategy. Heterogeneity in technical methods between studies produced differences in estimates, as did different diagnostic thresholds used.

CONCLUSIONS

The meta-analysis suggests a slightly higher prevalence of gestational diabetes mellitus in Canada and the United States, compared to Europe, but highlights the need for standardised protocols for estimating gestational diabetes mellitus prevalence.

Prevalence and risk factors contributing to the occurrence of diabetes mellitus in Chinese international migrants: A narrative review

AIMS

This paper reviewed the literature on diabetes prevalence and risk factors associated with diabetes among first-generation Chinese international migrants.

METHODS

MEDLINE, Scopus, Web of Science, CINAHL and Maternity and Infant Care were searched until March 2022, for articles written in English. The quality of the included articles was assessed using the Newcastle-Ottawa Scale.

RESULTS

In total, 17 articles were included (nine for gestational diabetes, six for type 2 diabetes, and none for type 1 diabetes). The average crude prevalence rate for type 2 diabetes and gestational diabetes was 12.1% and 9.3% respectively. Risk factors contributing to the occurrence of type 2 diabetes included older age, sex, family history of type 2 diabetes, higher BMI/waist circumference, longer time since migration, alcohol consumption, smoker, hypertension, and high triglycerides. Risk factors contributing to the occurrence of gestational diabetes included older maternal age, history of gestational diabetes, higher weight/pre-pregnancy BMI, longer time since migration, and Chinese ethnicity.

CONCLUSIONS

We identified a research gap in the diabetes health of Chinese migrants, particularly for type 1 diabetes, highlighting the need for ethnic-specific diabetes research and care, including for subsequent generations of migrants and those living in developing countries.

Evolution of Gestational Diabetes Mellitus across Continents in 21st Century

Over the last few decades, several definitions of gestational diabetes mellitus (GDM) have been described. There is currently not enough research to show which way is the best to diagnose GDM. Opinions differ in terms of the optimal screening and diagnostic measures, in part due to the differences in the population risks, the cost-effectiveness considerations, and the lack of an evidence base to support large national screening programs. The basic method for identifying the disease is the measurement of glucose plasma levels which may be determined when fasting, two hours after a meal, or simply at any random time. The currently increasing incidence of diabetes in the whole population, the altering demographics and the presence of lifestyle changes still require better methods of screening for hyperglycemia, especially during pregnancy. The main aim of this review is to focus on the prevalence and modifications to the screening criteria for GDM across all continents in the 21st century. We would like to show the differences in the above issues and correlate them with the geographical situation. Looking at the history of diabetes, we are sure that more than one evolution in GDM diagnosis will occur, due to the development of medicine, appearance of modern technologies, and the dynamic continuation of research.

Vitamin D Status of Infants of Mothers with Gestational Diabetes: Status at Birth and a Randomized Controlled Trial of Vitamin D Supplementation across Infancy

BACKGROUND

Vitamin D status and requirements of infants of women with gestational diabetes mellitus (GDM) are unclear.

OBJECTIVES

The objectives were to assess vitamin D status in infants of mothers with GDM and compare vitamin D status in response to 400 vs. 1000 IU/d vitamin D supplementation in infants born with serum 25-hydroxyvitamin D [25(OH)D] <50 nmol/L.

METHODS

Women with GDM delivering full-term infants (n = 98; March 2017-2019, Montreal, Canada) were surveyed for demographic and lifestyle factors. Pregnancy history was obtained from medical records. Newborn serum 25(OH)D was measured (immunoassay) and categorized as <30 (deficient) or ≥40 nmol/L (adequate). Breastfed neonates (n = 16) with serum 25(OH)D <50 nmol/L at birth were randomly assigned to 400 or 1000 IU/d of supplemental cholecalciferol (vitamin D3), and serum 25(OH)D was measured at baseline (≤1 mo) and 3, 6, and 12 mo of age. Groups were compared using a linear mixed-effects model and Tukey-Kramer post hoc tests.

RESULTS

Mean newborn serum 25(OH)D was 46.4 (95% CI: 43.9, 49.9) nmol/L, with 15.3% (95% CI: 8.2%, 22.4%) <30 nmol/L and 61.2% (95% CI: 51.6%, 70.9%) ≥40 nmol/L. During the trial, most infants were breastfed to 3 mo (400 IU/d: 87.5%; 1000 IU/d: 75.0%). Mean (± SEM) infant serum 25(OH)D was higher in the 1000-IU/d group at 3 mo (79.9 ± 5.9 vs. 111.5 ± 15.2 nmol/L; P = 0.0263), and although not different at 6-12 mo, was maintained at >50 nmol/L.

CONCLUSIONS

Most infants of women with GDM had adequate vitamin D status in this study. In those born with serum 25(OH)D <50 nmol/L, vitamin D status was corrected by 3 mo of age in response to 400 or 1000 IU/d of supplemental vitamin D. Dietary guidance should continue to recommend that all women who could become pregnant take a multivitamin supplement and that breastfed infants receive 400 IU/d of supplemental vitamin D. This study and ancillary trial were registered at clinicaltrials.gov (https://www.

CLINICALTRIALS

gov/ct2/show/NCT02563015) as NCT02563015.

Differences in the birthweight of infants born to patients with early- or mid-to-late-detected gestational diabetes mellitus who underwent guideline-based glycemic control

AIMS

To examine the effects of strict glycemic control on the birthweight of infants born to Japanese patients with early- or mid-to-late-detected gestational diabetes mellitus (ed- or md-GDM).

METHODS

We retrospectively examined the characteristics of 101 patients with GDM who underwent guideline-based glycemic control. A 75-g oral glucose tolerance test was conducted to diagnose GDM at gestational weeks 11-15 (ed-GDM subgroup) and 24-28 (md-GDM subgroup).

RESULTS

Infant birthweight was significantly lower in the ed-GDM subgroup (n = 25) than in the md-GDM subgroup (n = 76) (2688.3 ± 470.4 g vs. 3052.4 ± 383.1 g, p < 0.05), and the proportion of low-birthweight infants (<2500 g) was significantly higher in the ed-GDM subgroup than in the md-GDM subgroup (32.0% vs. 5.3%, p < 0.005). Fasting plasma glucose (FPG) levels during early treatment and before delivery were significantly lower in the ed-GDM subgroup than in the md-GDM subgroup (76.1 ± 10.4 mg/dL vs. 85.5 ± 9.6 mg/dL, p < 0.001; 80.5 ± 10.4 mg/dL vs. 90.4 ± 10.3 mg/dL, p < 0.0001).

CONCLUSIONS

Patients with ed-GDM showed significantly lower FPG levels during treatment compared to those with md-GDM, presumably indicating an association with the delivery of low-birthweight infants.

Could Subtle Obstetrical Brachial Plexus Palsy Be Related to Unilateral B Glenoid Osteoarthritis?

Background: Several factors associated with B glenoid are also linked with obstetrical brachial plexus palsy (OBPP). The purpose of this observational study was to determine the incidence of OBPP risk factors in type B patients. Methods: A cohort of 154 patients (68% men, 187 shoulders) aged 63 ± 17 years with type B glenoids completed a questionnaire comprising history of perinatal characteristics related to OBPP. A literature review was performed following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) to estimate the incidence of OBPP risk factors in the general population. Results: Twenty-seven patients (18%) reported one or more perinatal OBPP risk factors, including shoulder dystocia (n = 4, 2.6%), macrosomia >4 kg (n = 5, 3.2%), breech delivery (n = 6, 3.9%), fetal distress (n = 8, 5.2%), maternal diabetes (n = 2, 1.3%), clavicular fracture (n = 2, 1.3%), and forceps delivery (n = 4, 2.6%). The comparison with the recent literature suggested that most perinatal OBPP risk factors were within the normal range, although the incidence of shoulder dystocia, forceps and vaginal breech deliveries exceeded the average rates. Conclusion: Perinatal factors related to OBPP did not occur in a higher frequency in patients with Walch type B OA compared to the general population, although some of them were in the high normal range.

Seasonality of gestational diabetes mellitus and maternal blood glucose levels: Evidence from Taiwan

Previous studies have indicated that the prevalence of gestational diabetes mellitus (GDM) was related to the season. However, there was no relevant information in Asia. The aim of this study was to determine whether there was seasonality of GDM and maternal blood glucose level in Taiwanese women.A total of 6396 pregnancies were enrolled between 2012 and 2014 in this retrospective study. A 2-step approach according to the Carpenter-Coustan criteria was used for GDM diagnosis. A generalized linear mixed model was used to estimate the effect of season on GDM diagnosis by adjusting for age, prepregnancy body mass index, parity, history of GDM, fetal sex, and the rate of weight gain.During the study period, 418 (6.5%) pregnancies were diagnosed as GDM. The model demonstrated an increased prevalence of GDM in spring and summer (odds ratio: 1.59, 95% confidence interval: 1.13-2.24; odds ratio: 1.59, 95% confidence interval: 1.14-2.23, respectively) compared to winter. For the glucose level variation, the model demonstrated an increase of 2.56 mg/dL glucose in the 50-g glucose challenge test in summer compared to winter. In glucose challenge test-positive pregnancies, the season also had an effect on the results of the 100-g 1-h, 2-h, and 3-h oral glucose tolerance tests, but no effect on the 100-g fasting oral glucose tolerance tests.GDM prevalence in Taiwan presents seasonal variation, with the highest risk during spring and summer due to post-glucose load level variations. These findings could serve as reference data for countries in Southeast Asia or areas with a similar climate.

Measuring maternal body composition by biomedical impedance can predict risk for gestational diabetes mellitus: a retrospective study among 22,223 women

OBJECTIVES

This study aimed to identify which element of body composition measurements taken before 17th week gestation was the strongest risk factor for gestational diabetes mellitus (GDM) in Chinese pregnant women.

DESIGN AND SETTING

A retrospective study was performed using data retrieved from the Electronic Medical Record database of Chongqing Health Center for Women and Children (China) from January 2014 to December 2015.

PARTICIPANTS

A total of 22,223 women were included with singleton pregnancies and no preexisting diabetes who underwent bioelectrical impedance analysis (BIA) before 17 gestational weeks and 75-g OGTT at 24-28 gestational weeks.

RESULTS

The prevalence of GDM from 2014 to 2015 was 27.13% (IADPSG). All indicators of BIA (total body water, fat mass, fat-free mass, percent body fat, muscle mass, visceral fat levels, proteins, bone minerals, basal metabolic rate, lean trunk mass), age, weight and body mass index (BMI) were risk factors that significantly increased the occurrence of GDM (p < .001 for all). Women older than 30 years or with a BMI more than 23, had a significantly higher GDM prevalence (34.89% and 34.77%). After adjusted covariates, visceral fat levels at the third quartile, the ORs of GDM were 1.142 (95% CI 1.032-1.263) in model I and 1.419 (95% CI 1.274-1.581) in model II used the first quartile as reference (p < .05 for both); bone minerals at the third quartile, the ORs of GDM were 1.124 (95% CI 1.020-1.238) in model I and 1.311 (95% CI 1.192-1.442) in model II (p < .05 for both). After adjusted for age, visceral fat levels and bone minerals, OR of GDM for percent body fat more than 28.77% at the third quartile was 1.334 (95% CI 1.201-1.482) in model II (p < .05 for both).

CONCLUSIONS

Visceral fat levels, bone minerals and percent body fat were significantly associated with an increased risk of GDM, providing the reference ranges of visceral fat levels, bone minerals and percent body fat as predictive factors for Chinese women to estimate the risk of GDM by BIA during pregnancy.

The effect of gestational diabetes mellitus on sufentanil consumption after cesarean section: a prospective cohort study

Background

Previous studies have shown that patients with long-term diabetes require more opioids after surgery than patients without diabetes. Gestational diabetes mellitus (GDM) normally only lasts for a brief period; nevertheless, its effect on sufentanil consumption after cesarean section is unknown.

Methods

This prospective cohort study included two groups: a GDM group (n = 32) and a matched non-GDM (NGDM) group (n = 32). All patients underwent routine combined spinal-epidural anesthesia for cesarean delivery. Sufentanil consumption through an intravenous patient-controlled analgesia (PCA) pump, the frequency of PCA requests, and visual analog scale (VAS) scores 6 and 24 h after surgery were compared between groups.

Results

Sufentanil consumption (μg) 6 h after surgery was higher in the GDM group than in the NGDM group (24.0 ± 6.6 vs 20.1 ± 5.7, P = 0.023). PCA was used more frequently 6 and 24 h after surgery by the GDM group than by the NGDM group (1[0–2] vs 0[0–1], P = 0.001; 6 [1–5] vs 3 [1, 2, 6–8], P = 0.001, respectively). The VAS score during activity 24 h after surgery was higher in the GDM group than in the NGDM group (5 [2, 3] vs 5 [1, 2], respectively, P = 0.03).

Conclusion

Pregnant women with GDM require more opioids during the immediate postoperative period after cesarean section than those without GDM.

Clinical trials registration

No. ChiCTR1800016014, ChenYang, May 6th 2018.

The Sex Specific Association Between Maternal Gestational Diabetes and Offspring Metabolic Status at 1 Year of Age

Previous studies showed the association between maternal GDM and long-term effects of overweight in offspring. However, the nature of this association in the early postnatal period is still undetermined. The aim of this prospective cohort study was to evaluate whether maternal GDM is associated with overweight and obesity status in offspring at age 1 year. We studied 1167 infants born at a large obstetrical care hospital including 778 normal glucose tolerance (NGT) and 389 GDM pregnancies, matched in a 1:2 ratio according to offspring's gender, during the years 2016-2017. Overweight and obesity status in offspring of both groups were evaluated at 1 year of age through questionnaires. Infant outcomes were defined according to the WHO Child Growth Standards based on the length-based BMI-for-age. Female offspring from the GDM group exhibited a higher mean BMI (17.2 vs. 16.6, p < 0.01), a higher rate of obesity (13.9% vs. 7.7%; p < 0.05), and overweight (33.1% vs. 23.5%; p < 0.05) as compared to the NGT female group. In the multivariable regression model, maternal GDM was found to be independently and significantly associated with overweight or obesity in 1-year aged female offspring only (OR 1.61, 95% CI 1.09-2.37, p < 0.05). We found a sex specific association between maternal GDM and the overweight risk only in female offspring at 1 year of age.

Characteristics of Women With Gestational Diabetes From Non-Caucasian Compared With Caucasian Ethnic Groups

OBJECTIVES

Short- and long-term outcomes in women after gestational diabetes mellitus (GDM) vary by ethnicity. Understanding differences in baseline diabetes risk factors is important for informing choice of risk-reducing interventions. We aimed to compare maternal and pregnancy-related characteristics in Caucasian and non-Caucasian women with GDM.

METHODS

Using a large multicentre Canadian cohort of women diagnosed with GDM and recruited between 2009 and 2013, we compared demographic, clinical and behavioural characteristics in women with GDM across 7 ethnic groups. Data were obtained from chart reviews and surveys, and logistic and linear regression models were used to compare binary and continuous variables, respectively, between Caucasian and non-Caucasian ethnic groups.

RESULTS

Of the 1,332 women with GDM, 911 were eligible for inclusion. Of these, 41.4% were white Caucasian, 17.1% were South Asian, 18.4% were East Asian, 5.8% were black, 8.8% were Filipina, 5.2% were Middle Eastern and 3.3% were Hispanic. Non-Caucasian women were diagnosed with GDM at a younger age and were more likely to have a family history of diabetes compared with Caucasian women. With the exception of East Asians, non-Caucasian women were more likely to be overweight using ethnicity-specific body mass index cutoffs and have higher oral glucose tolerance test values than Caucasian women. Prepregnancy smoking and alcohol consumption prevalence were highest in Caucasian women.

CONCLUSIONS

Several important ethnicity-specific differences in clinical and behavioural characteristics of women with GDM were identified. These differences need to be considered when offering interventions for reducing risk of adverse perinatal outcomes and subsequent type 2 diabetes.

The Burden of Atherosclerotic Cardiovascular Disease in South Asians Residing in Canada: A Reflection From the South Asian Heart Alliance

South Asians (SAs), originating from the Indian subcontinent (India, Pakistan, Sri Lanka, Bangladesh, Nepal, and Bhutan), represent one quarter of the global population and are the largest visible minority in Canada. SAs experience the highest rates of coronary artery disease in Canada. Although conventional cardiovascular risk factors remain predictive in SA, the excess risk is not fully explained by these risk factors alone. Abdominal obesity, metabolic syndrome, and insulin resistance likely contribute a greater risk in SAs than in other populations. The South Asian Heart Alliance has been recently formed to investigate and recommend the best strategies for the prevention of cardiometabolic disease in SAs in Canada. This topic review represents a comprehensive overview of the magnitude of cardiovascular disease in SAs in Canada, with a review of conventional and novel risk markers in the SA population. Both primary and secondary prevention strategies are suggested and when possible, adapted specifically for the SA population. The need for SAs and their healthcare professionals to be more aware of the problem and potential solutions, along with the need for population-specific research, is highlighted.

Gestational weight gain targets during the second and third trimesters of pregnancy for women with gestational diabetes mellitus in China

BACKGROUND/OBJECTIVES

Gestational weight gain (GWG) recommendations for pregnant women with gestational diabetes mellitus (GDM) in China are lacking. The present study aims to examine whether specific GWG targets for women with GDM can improve pregnancy outcomes in comparison with GWG according to the Institute of Medicine (IOM) targets.

SUBJECTS/METHODS

Pregnant women diagnosed with GDM were selected from a retrospective cohort study of 8299 singleton pregnant women aged 18-45 years in 2012 (n = 1820). GWG ranges were calculated using a receiver operating characteristic (ROC) curve analysis (ROC targets) and the interquartile range (IR) method (the range from the 25th to 75th percentiles of the GWG among GDM women without adverse pregnancy outcomes, IR targets).

RESULTS

The incidences of small for gestational age (SGA) births and pregnancy hypertension among women with GDM who gained weight within the ROC targets were lower than the incidences in women who gained weight within the IOM targets (SGA, 7.5% vs. 8.6%; pregnancy hypertension, 12.6% vs. 14.1%; both P < 0.05). GWG was associated with a risk of adverse pregnancy outcomes in the total sample (estimated values ranged from -2.95 to 2.08, all P < 0.05). No statistically significant associations between GWG and adverse pregnancy outcomes were observed in subgroups of pregnant women with appropriate GWGs according to the ROC, IR, and IOM targets. The ROC targets exhibited higher negative predictive values for adverse pregnancy outcomes than the IR and IOM targets.

CONCLUSION

The ROC targets improved pregnancy outcomes and thus represent potential special GWG guidelines for women with GDM in China.

A Population-level Analysis of the Differing Effects of Rheumatoid Arthritis and Spondyloarthritis on Peripartum Outcomes

OBJECTIVE

The effects of rheumatoid arthritis (RA) and spondyloarthritis (SpA) on maternal and neonatal outcomes at a population level have not previously been well compared.

METHODS

A contemporary pregnancy cohort of 312,081 women and corresponding birth events was assembled for the province of Alberta from the random selection of 1 live birth event per woman. We identified 3 groups: (1) no inflammatory arthritis (no IA, n = 308,989), (2) RA (n = 631), and (3) SpA (n = 2461). We compared maternal and neonatal outcomes, comorbid conditions, and medication use among the 3 groups. Multivariable logistic regression models evaluated the independent association between RA and SpA, relative to no IA, and the outcomes of small for gestation age (SGA) and hypertensive disorders during pregnancy.

RESULTS

Pregnant women with RA were significantly more likely to have preterm delivery (13.5%), cesarean delivery (33.9%), hypertensive disorders in pregnancy (10.5%), and SGA babies (15.6%), compared to pregnant women with either SpA or no IA. Nonsteroidal antiinflammatory drugs and corticosteroid use were significantly higher in pregnant women with RA compared to the other groups. Women with RA were significantly more likely to have an SGA baby (OR 1.51, 95% CI 1.21-1.88; p < 0.01), and hypertensive disorder in pregnancy (OR 1.51, 95% CI 1.16-1.97; p < 0.01), compared to women with no IA, while no difference was found between women with SpA and those with no IA.

CONCLUSION

Women with RA have a higher risk of worse maternal and neonatal outcomes, whereas the risk of these events is similar between women with and without SpA.

Exposure to heavy metals during pregnancy related to gestational diabetes mellitus in diabetes-free mothers

Evidence is cumulating on the adverse health effects of environmental exposures on health of the fetus and the childbearing mothers. Among mother's conditions, gestational diabetes mellitus has been considered rarely in spite of its importance for both mother and child. We determined the role of maternal exposure to lead (Pb), cadmium (Cd) and manganese (Mn) to gestational diabetes mellitus (GDM) on diagnosed GDM and impaired glucose tolerance (IGT) in diabetes-free mothers from the French EDEN mother-child cohort. 623 pregnant women without pre-existing diabetes were included in the study. GDM and IGT were diagnosed by a gynecologist during consultations after blood analysis. Pb, Cd and Mn were measured in second-trimester blood samples. Associations between ln-transformed concentrations of metals and GDM and IGT respectively were examined using multiple logistic regression analysis adjusted for potential confounders. The prevalences of GDM and IGT were 7.1% and 10.1% respectively. After adjustment for confounders, Cd was statistically related to having had a diagnosis of GDM or IGT (Adjusted Odds-Ratio (AOR): 1.61, 1.05-2.48), and Pb to GDM at borderline significance (AOR: 1.65, 0.82-3.34). Our findings add to the growing evidence supporting the role of maternal exposure to heavy toxic metals that persist longtime in the environment as a risk factor for GDM.

The impact of diagnostic criteria for gestational diabetes on its prevalence: a systematic review and meta-analysis

BACKGROUND

The absence of universal gold standards for screening of gestational diabetes (GDM) has led to heterogeneity in the identification of GDM, thereby impacting the accurate estimation of the prevalence of GDM. We aimed to evaluate the effect of different diagnostic criteria for GDM on its prevalence among general populations of pregnant women worldwide, and also to investigate the prevalence of GDM based on various geographic regions.

METHODS

A comprehensive literature search was performed in PubMed, Scopus and Google-scholar databases for retrieving articles in English investigating the prevalence of GDM. All populations were classified to seven groups based-on their diagnostic criteria for GDM. Heterogeneous and non-heterogeneous results were analyzed using the fixed effect and random-effects inverse variance model for calculating the pooled effect. Publication bias was assessed by Begg's test. The Meta-prop method was used for the pooled estimation of the prevalence of GDM. Meta-regression was conducted to explore the association between prevalence of GDM and its diagnostic criteria. Modified Newcastle-Ottawa Quality Assessment Scale for nonrandomized studies was used for quality assessment of the studies included; the ROBINS and the Cochrane Collaboration's risk of bias assessment tools were used to evaluate the risk of bias.

RESULTS

We used data from 51 population-based studies, i.e. a study population of 5,349,476 pregnant women. Worldwide, the pooled overall-prevalence of GDM, regardless of type of screening threshold categories was 4.4%, (95% CI 4.3-4.4%). The pooled overall prevalence of GDM in the diagnostic threshold used in IADPSG criteria was 10.6% (95% CI 10.5-10.6%), which was the highest pooled prevalence of GDM among studies included. Meta-regression showed that the prevalence of GDM among studies that used the IADPSG criteria was significantly higher (6-11 fold) than other subgroups. The highest and lowest prevalence of GDM, regardless of screening criteria were reported in East-Asia and Australia (Pooled-P = 11.4%, 95% CI 11.1-11.7%) and (Pooled-P = 3.6%, 95% CI 3.6-3.7%), respectively.

CONCLUSION

Over the past quarter century, the diagnosis of gestational diabetes has been changed several times; along with worldwide increasing trend of obesity and diabetes, reducing the threshold of GDM is associated with a significant increase in the incidence of GDM. The harm and benefit of reducing the threshold of diagnostic criteria on pregnancy outcomes, women's psychological aspects, and health costs should be evaluated precisely.

Ethnic Disparities in Gestational Diabetes

PURPOSE OF REVIEW

Ethnicity has long been described as a major risk factor for the development of gestational diabetes mellitus (GDM), and it is widely recognised that women from ethnicities other than Europids are at higher risk of developing GDM. There are also described differences between ethnicities in key GDM pregnancy outcomes. This review describes some of the factors that relate to the ethnic disparities in GDM.

RECENT FINDINGS

The global prevalence of GDM has been steadily increasing and estimated to be 16.2% from the International Diabetes Federation extrapolation. Reported prevalence rates may understate the true prevalence, due to factors of access and attitudes to GDM diagnosis and screening in low resource settings for foreign-born women and indigenous populations. Other factors may relate to genes associated with specific ethnicities, obesity, body composition and gestational weight gain. Various factors such as access to screening, body composition, genetics and gestational weight gain may result in ethnic disparities in the prevalence and outcomes of GDM.

Association between serum arsenic levels and gestational diabetes mellitus: A population-based birth cohort study

Gestational diabetes mellitus (GDM) is a common obstetric complication with adverse effects on both mothers and their children. Previous studies revealed the link between Arsenic (As) exposure and incidence of diabetes mellitus (DM), but the data on the association between maternal As exposure and GDM is scarce. We examined this association among a population-based birth cohort. As concentrations were determined at multiple time points during pregnancy by ICP-MS. The association between As levels and GDM prevalence was examined using logistic regression model after adjustment for confounders. A total of 419 (12.85%) women were diagnosed with GDM. The incidences of GDM gradually increased with increasing quartiles of As levels with significant trend. As levels were associated with the GDM (95%CI: 1.29-2.43) at only the 4th quartile in the first trimester. After adjustment for maternal age, prepregnancy body mass index (BMI), monthly income, gestational age and parity, the association remains significant (95%CI: 1.22-2.38). Stratified analyses showed the associations were largely limited to normal maternal age (95%CI: 1.19-3.04) and normal weight women (95%CI: 1.18-2.66). Our study showed an association between As and GDM in a birth cohort and explored first trimester may be the critical period for As associated GDM. This association was universal in the general pregnant population of normal age and of normal weight.

Gestational diabetes care and outcomes for refugee women: a population-based cohort study

AIM

To determine the prevalence of adverse clinical outcomes, the rates of healthcare utilization, and the incidence of post-partum Type 2 diabetes in refugees with gestational diabetes (GDM), compared with other immigrants and non-immigrants.

METHODS

A population-based cohort study was conducted using healthcare databases in Ontario, Canada. Over 40 000 women with GDM having singleton live births between 2002 and 2014 were identified. We identified GDM adverse outcomes such as macrosomia, pre-eclampsia and respiratory distress syndrome. Antenatal and newborn healthcare utilization were ascertained. Women were then followed for diagnosis of diabetes post-partum.

RESULTS

Both refugees and other immigrants had a lower rate than non-immigrants of many adverse GDM outcomes, including pre-eclampsia [relative risk (RR) 0.65, 95% confidence interval (95% CI) 0.44-0.95 and 0.61, 95% CI 0.52-0.72, respectively], preterm birth (RR 0.87, 95% CI 0.75-0.995 and 0.85, 95% CI 0.80-0.91, respectively), and respiratory distress syndrome (RR 0.83, 95% CI 0.70-0.97 and 0.78, 95% CI 0.72-0.84, respectively). However, refugees were less likely to attend well-baby care in time for the first routine vaccination (RR 0.92, 95% CI 0.88-0.95). Incidence of post-partum diabetes was high in all groups, but refugee women were at increased risk (hazard ratio 1.23, 95% CI 1.11-1.37).

CONCLUSIONS

Despite different circumstances leading to migration, refugees have a similar 'healthy immigrant effect' to other immigrants, with respect to adverse GDM outcomes. However, newborns of refugees were less likely to have well-baby care, and refugee women were also at especially high risk of developing diabetes post-partum. These are both important public health issues.