Surprisingly low compliance to local guidelines for risk factor based screening for gestational diabetes mellitus - A population-based study

Gestational diabetes mellitus and subsequent cardiovascular disease in a period of rising diagnoses: Cohort study

INTRODUCTION

Evidence suggests that gestational diabetes mellitus (GDM) is associated with subsequent cardiovascular disease; however, it is unclear what impact changes in screening and diagnostic criteria have had on the association of GDM with long-term outcomes such as cardiovascular disease. The purpose of this study was to determine the association between GDM and subsequent cardiovascular disease during a period of rising gestational diabetes diagnosis in England. Specifically, associations were compared before and after 2008, when national guidelines supporting risk factor-based screening were introduced.

MATERIAL AND METHODS

We conducted a cohort study using routinely collected data from the Clinical Practice Research Datalink linked to the Hospital Episode Statistics and Office for National Statistics databases. The study consisted of persons aged 15-45 years with a livebirth or stillbirth between 1998 and 2017 and without a history of cardiovascular disease or pre-pregnancy diabetes mellitus. Cox proportional hazards models, with propensity score weighting using matching weights, were used to estimate adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) for the association of GDM diagnosis in the first recorded pregnancy with subsequent cardiovascular disease.

RESULTS

Among 232 315 individuals, the incidence of cardiovascular disease was 6.6 per 1000 person-years among those with GDM and 2.2 per 1000 person-years among those without GDM over a mean follow-up duration of 5.8 years. The overall aHR, 95% CI was 1.91 (1.41, 2.60). Diagnosis of GDM increased over the study period, from 0.7% in 1998-99 to 5.3% in 2017. The effect size was not markedly different in the years before (1998-2007: adjusted HR 2.05, 95% CI 2.05 1.35, 3.12) and after 2008 (2008-2017: adjusted HR 1.79, 95% CI 1.15, 2.80).

CONCLUSIONS

There was a strong association of GDM with cardiovascular disease after accounting for social and demographic factors and multiple comorbidities, and this association was present both before and after 2008, when national gestational diabetes screening criteria were established.

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.

Obstetrical Outcome following Diagnosis of Gestational Diabetes in the Third Trimester (>29 Weeks) versus Second Trimester (24-28 Weeks): A Retrospective Comparative Study

OBJECTIVE

This study aimed to compare obstetrical outcomes between women diagnosed with gestational diabetes mellitus (GDM) in the third trimester after testing negative for GDM in two-step screening in the second trimester and women diagnosed in the second trimester.

STUDY DESIGN

This retrospective study compared obstetrical outcomes between 375 women diagnosed with GDM in the second trimester and 125 diagnosed in the third trimester.

RESULTS

Among women diagnosed with GDM in the third versus second trimester, the incidences were higher of morbid obesity (body mass index ≥35 kg/m2), macrosomia, and cesarean section (CS) due to suspected macrosomia: 23.2 versus 9.8%, p < 0.001; 44.0 versus 10.1%, p < 0.001; and 24.8 versus 6.3%, p < 0.001, respectively. For those diagnosed in the third versus second trimester, the incidences were lower of hypertensive disorders of pregnancy and intrauterine growth restriction, and a lower proportion of women needed pharmacological therapy for glucose control: 2.4 versus 9.0%, p = 0.016; 0.8 versus 8.2%, p < 0.001; and 12.0 versus 29.7%, p < 0.001, respectively. Multivariate analysis supported a correlation between third-trimester-diagnosed GDM and macrosomia, and between second-trimester-diagnosed GDM and hypertensive disorders of pregnancy.

CONCLUSION

Among women diagnosed with GDM in the third compared with the second trimester, the incidence of morbid obesity was higher; accordingly, the risks were higher for large for gestational age infants and delivery by CS, and lower for hypertensive disorders. Guidelines regarding repeat oral glucose tolerance testing in the third trimester should be considered following prospective studies.

KEY POINTS

· Third-trimester GDM was 29.9% among women with normal second-trimester screening.. · Morbid obesity and macrosomia were more frequent in third- versus second-trimester GDM.. · Incidence of preeclampsia was lower in third- versus second-trimester-diagnosed GDM..

Pre-analytical diagnostic differences despite high adherence to guidelines for gestational diabetes mellitus

Regional variations in the prevalence of gestational diabetes mellitus (GDM) have been found across Denmark. The objectives of this exploratory survey were to evaluate adherence to the national guideline for screening and diagnosing GDM and to identify variations in pre-analytical or analytical factors, which could potentially contribute to variations in GDM prevalence across regions. In a national interview-based survey, obstetric departments and laboratories throughout Denmark handling GDM screening or diagnostic testing were invited to participate. Survey questionnaires were completed through personal interviews. In total, 21 of 22 identified obstetric departments and 44 of 45 identified laboratories participated. Adherence to guideline among obstetric departments ranged 67-100% and uniformity in laboratory procedures was high. However, the gestational age at the time of late diagnostic testing with oral glucose tolerance test (OGTT) varied considerably, with 48% (10/21) of departments testing outside the recommended 24-28 weeks' gestation. Procedural heterogeneity was most pronounced for the parts not described in current guidelines, with choice of laboratory equipment being the most diverse factor ranging 3-39% nationally. In conclusion, the overall adherence to the national guidelines was high across regions, and obstetric departments and laboratories had high uniformity in the procedures for screening and diagnosing GDM. Uniformity was generally high for procedures included in the guideline and low if not included. However, a high proportion of GDM testing was performed outside the recommended gestational window in late pregnancy, which may be a pre-analytical contributor to regional differences in GDM prevalence.

Associations between maternal metabolic conditions and neurodevelopmental conditions in offspring: the mediating effects of obstetric and neonatal complications

BACKGROUND

Maternal pre-gestational diabetes (PGDM), gestational diabetes mellitus (GDM), and overweight/obesity have been associated with increased risks of offspring neurodevelopmental conditions (NDCs) including autism, intellectual disability (ID), and attention deficit/hyperactivity disorder (ADHD). Less is known about whether and how obstetric and neonatal complications (e.g., preterm birth, neonatal asphyxia) could mediate these associations.

METHODS

In this Swedish register-based cohort study, we examined complications during pregnancy, delivery, and the neonatal period as potential mediators of the relationships between maternal metabolic conditions and offspring NDCs. We quantified the extent to which these obstetric and neonatal factors could mediate the associations of maternal metabolic conditions with offspring NDCs by applying parametric regression models for single mediation analyses and weighting-based methods for multiple mediation analyses under counterfactual frameworks.

RESULTS

The study sample included 2,352,969 singleton children born to 1,299,692 mothers from 1987-2010 who were followed up until December 31, 2016, of whom 135,832 children (5.8%) were diagnosed with at least one NDC. A substantial portion of the association between maternal PGDM and children's odds of NDCs could be explained by the combined group of obstetric and neonatal complications in the multiple mediation analysis. For instance, these complications explained 44.4% of the relationship between maternal PGDM and offspring ID risk. The proportion of the relationship between maternal overweight/obesity and children's risk of NDCs that could be explained by obstetric and neonatal complications was considerably smaller, ranging from 1.5 to 8.1%. Some complications considered on their own, including pregnancy hypertensive diseases, preterm birth, neonatal asphyxia, and hematological comorbidities, could explain at least 10% of the associations between maternal PGDM and offspring NDCs. Complications during the neonatal period showed a stronger joint mediating effect for the relationship between PGDM and offspring NDCs than those during pregnancy or delivery.

CONCLUSIONS

Obstetric and neonatal complications could explain nearly half of the association between maternal PGDM and offspring risk of NDCs. The mediating effects were more pronounced for complications during the neonatal period and for specific complications such as pregnancy hypertensive diseases, preterm birth, neonatal asphyxia, and hematological comorbidities. Effective preventive strategies for offspring NDCs should holistically address both the primary metabolic issues related to PGDM and the wide array of potential complications, especially those in the neonatal period.

Midwives' and Diabetes Nurses' Experience of Screening and Care of Women with Gestational Diabetes Mellitus: A Qualitative Interview Study

Background

Gestational diabetes mellitus (GDM) is increasing and is associated with adverse outcomes for both mother and child. The metabolic demands of pregnancy can reveal a predisposition for type 2 diabetes mellitus (T2DM), and women with a history of GDM are more likely to develop T2DM than women with normoglycemic pregnancies.

Aim

The aim of this study was to explore midwives' and diabetes nurses' experience of their role in screening, care, and follow-up of women with gestational diabetes mellitus and, further, to explore their opinions and thoughts about existing routines and guidelines.

Method

Individual interviews were performed with ten diabetes nurses and eight midwives working in primary and special care. Qualitative content analysis was done according to Graneheim and Lundman.

Results

The analysis of the interviews resulted in the overall theme "An act of balance between normalcy and illness, working for motivation with dilemmas throughout the chain of health care." Difficulties in carrying out the important task of handling GDM while at the same time keeping the pregnancy in focus were central. Women were described as highly motivated to maintain a healthy lifestyle during pregnancy with the baby in mind, but it seemed difficult to maintain this after delivery, and compliance with long-term follow-up with the aim of reducing the risk of T2DM was low. The women came to the first follow-up but did not continue with later contact. This was at a time when the women felt healthy and were focusing on the baby and not themselves. A lack of cooperation and easy access to a dietician and physiotherapist were pointed out as well as a wish for resources such as group activities and multiprofessional teams.

Validation of Insurance Billing Codes for Monitoring Antenatal Screening

BACKGROUND

Prevalence statistics for pregnancy complications identified through screening such as gestational diabetes usually assume universal screening. However, rates of screening completion in pregnancy are not available in many birth registries or hospital databases. We validated screening-test completion by comparing public insurance laboratory and radiology billing records with medical records at three hospitals in British Columbia, Canada.

METHODS

We abstracted a random sample of 140 delivery medical records (2014-2019), and successfully linked 127 to valid provincial insurance billings and maternal-newborn registry data. We compared billing records for gestational diabetes screening, any ultrasound before 14 weeks gestational age, and Group B streptococcus screening during each pregnancy to the gold standard of medical records by calculating sensitivity and specificity, positive predictive value, negative predictive value, and prevalence with 95% confidence intervals (CIs).

RESULTS

Gestational diabetes screening (screened vs. unscreened) in billing records had a high sensitivity (98% [95% CI = 93, 100]) and specificity (>99% [95% CI = 86, 100]). The use of specific glucose screening approaches (two-step vs. one-step) were also well characterized by billing data. Other tests showed high sensitivity (ultrasound 97% [95% CI = 92, 99]; Group B streptococcus 96% [95% CI = 89, 99]) but lower negative predictive values (ultrasound 64% [95% CI = 33, 99]; Group B streptococcus 70% [95% CI = 40, 89]). Lower negative predictive values were due to the high prevalence of these screening tests in our sample.

CONCLUSIONS

Laboratory and radiology insurance billing codes accurately identified those who completed routine antenatal screening tests with relatively low false-positive rates.

Changed definition of disease and broader screening criteria had little impact on prevalence of gestational diabetes mellitus

INTRODUCTION

There are major controversies in screening for gestational diabetes mellitus (GDM). The present study evaluates the impact of the 2017 revised guidelines for GDM screening and a changed definition of GDM in Norway.

MATERIAL AND METHODS

We used a case-series design and included women with no pre-pregnancy diabetes mellitus, who gave birth after gestational week 29 to a singleton fetus at the University Hospital of North Norway, Tromsø, or at a local maternity ward in Troms county, during the first 6 months of 2013 (before group, n = 676) and 2018 (after group, n = 673). Data were collected from antenatal records, maternal health information sheets, and electronic medical records (Partus). We assessed the screening criteria age, parity, pre-pregnancy BMI, and ethnicity. Primary outcomes were change in size of the population eligible for GDM screening, screening adherence, and prevalence of GDM, and follow up of GDM (treatment and obstetric risk assessment at gestational week 36). Statistical analyses were done using IBM SPSS with chi-squared test. A p value less than 0.05 was considered statistically significant.

RESULTS

The proportion of women eligible for GDM screening increased from 46.4% in the before group to 67.6% in the after group (+45%) (p < 0.01). However, screening adherence among eligible women was only 28.3% and 49.2% in the before and after groups, respectively (p < 0.01). Among screened women, 16.9% (15/89) and 10.7% (24/224), respectively, were diagnosed with GDM, resulting in an overall estimated prevalence of 2.2% (15/676) and 3.6% (24/673). Among women diagnosed with GDM, 13.3% received no follow up in 2013 and this proportion was 20.8% in 2018. The remaining women underwent obstetric risk assessment at gestational week 36 as advised in the guidelines.

CONCLUSIONS

The introduction of broader screening criteria and a more liberal case definition increased the population eligible for GDM screening by 45%. The higher proportion of women screened resulted in an insignificant higher prevalence of GDM. Screening adherence was poor in both study groups. Stakeholders for obstetric care need to consolidate quality measures and revisit the screening algorithm.

Antipsychotic Use During Pregnancy and Risk for Gestational Diabetes: A National Register-Based Cohort Study in Sweden

OBJECTIVE

We aimed to study whether antipsychotic use during pregnancy is associated with gestational diabetes.

METHODS

This was a Swedish national register-based cohort study on the Medical Birth Register and the Prescribed Drug Register including all 1,307,487 singleton births between July 2006 and December 2017. Antipsychotics were divided into first-generation antipsychotics (n = 728), high-risk metabolic second-generation antipsychotics including olanzapine, clozapine and quetiapine (n = 1710), and other second-generation antipsychotics (n = 541). The risks for gestational diabetes, foetal growth disturbances, pre-eclampsia, caesarean section and preterm labour were assessed. Women treated during pregnancy were compared to women not treated during pregnancy and to women who used antipsychotics before/after but not during pregnancy.

RESULTS

The crude risk ratio for gestational diabetes for women treated with high-risk metabolic second-generation antipsychotics during pregnancy was 2.2 (95% confidence interval [CI] 1.6-2.9) compared to untreated pregnant women (n = 1,296,539) and 1.8 (95% CI 1.4-2.5) compared to women treated before/after pregnancy (n = 34,492). After adjustment for maternal factors including body mass index, the risk ratios were 1.8 (95% CI 1.3-2.4) and 1.6 (95% CI 1.2-2.1). Exposed infants had an increased risk of being large for gestational age: adjusted risk ratios 1.6 (95% CI 1.3-1.9) and 1.3 (95% CI 1.1-1.6) compared to no maternal antipsychotic use during pregnancy and maternal use before/after the pregnancy. Other antipsychotics were not associated with metabolic risks.

CONCLUSIONS

Olanzapine, clozapine and quetiapine used during pregnancy were associated with increased risks for gestational diabetes and the infant being large for gestational age. Enhanced metabolic monitoring should be considered for pregnant women using these drugs.

Improving Utilization of Aspirin for Prevention of Preeclampsia in a High-Risk Urban Cohort: A Prospective Cohort Study

OBJECTIVE

This study aimed to evaluate the utilization of aspirin for preeclampsia prevention before and after implementation of a screening tool during nuchal translucency (NT) ultrasound.

STUDY DESIGN

One-year prospective cohort study of patients at high risk for preeclampsia after the implementation of a screening tool (postscreen) administered to all patients at check in for NT (11-13 weeks) ultrasound. Prospective cohort was compared with one-year retrospective cohort (prescreen) the year prior (2017). All patients who presented for NT ultrasound in both cohorts were evaluated for the presence of one or more risk factor for preeclampsia with screening tool collected prospectively and chart review retrospectively. Provider recommendation for aspirin determined by documentation in prenatal record. Primary outcome was rate of provider recommendation for aspirin pre versus post screening tool, compared by Chi-square test and adjusted for potential confounders with multiple regression analysis.

RESULTS

Pre- (n = 156) and postscreen (n = 136) cohorts were similar except for race and multifetal gestation. Prescreen, rate of provider recommendation for aspirin was 74%. Of those with prior preeclampsia, 96% were recommended aspirin, compared with 64% of patients with other risk factors (p < 0.001). Postscreen, provider recommendation of aspirin improved to 95% (p < 0.001). Rate of preeclampsia/gestational hypertension were similar between cohorts; however, there was a reduced adjusted risk in overall preterm birth <37 weeks (adjusted odds ratio [aOR] = 0.50 [0.25-0.99]) and preterm birth <34 weeks (aOR = 0.33 [0.13-0.88]) postscreening tool implementation.

CONCLUSION

Prior to implementation of a simple screening questionnaire, approximately 25% of high risk patients did not receive the recommendation of aspirin for preeclampsia prevention. High-risk patients who lack a history of preeclampsia were less likely to be advised of aspirin prophylaxis. Use of a simple universal screening tool at time of NT ultrasound significantly improved utilization of aspirin for preeclampsia prevention and may improve patient outcomes.

KEY POINTS

· Despite recommendations, aspirin use for preeclampsia prevention is suboptimal.. · High-risk patients who lack a history preeclampsia were less likely to be advised of aspirin use.. · A simple universal screening tool can significantly improve aspirin utilization..

Adherence to oral glucose tolerance testing in children in stage 1 of type 1 diabetes: The TEDDY study

OBJECTIVE

To examine adherence to the oral glucose tolerance test (OGTT) in multiple islet autoantibody children in stage 1 of developing type 1 diabetes (T1D).

METHODS

Children are followed from birth in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Completion of an OGTT is recommended every 6 months in children ≥3 years of age who are multiple islet autoantibody positive. Factors associated with adherence to the OGTT protocol were examined.

RESULTS

The average subject level adherence with the OGTT protocol was 62% although there were large differences across countries; Finnish participants and older children from Sweden were more adherent than participants from the United States and Germany. Factors associated with nonadherence included having a first-degree relative with T1D, using a local laboratory rather than a TEDDY center for the OGTT, and maternal underestimation of the child's risk for T1D. Children were more adherent to the OGTT if their mothers: were more satisfied with TEDDY participation, reported monitoring the child for T1D by checking blood glucose levels at home, and viewed participating in TEDDY as the primary way they were monitoring the child for T1D.

CONCLUSIONS

In a study of children in stage 1 of T1D, adherence to an OGTT protocol was suboptimal despite extensive efforts to communicate the child's high risk to parents. These findings provide important guidance for development of strategies to improve methods for detecting progression or the development of T1D in high-risk pediatric populations.

Adherence rates to a prediction tool identifying women with an increased gestational diabetes risk: An implementation study

OBJECTIVE

The best screening strategy for gestational diabetes mellitus (GDM) remains a topic of debate. Several organizations made a statement in favor of universal screening, but the volume of oral glucose tolerance tests (OGTT) required may burden healthcare systems. As a result, many countries still rely on selective screening using a checklist of risk factors, but reported diagnostic characteristics vary. Moreover, women's discomfort due to an OGTT is often neglected. Since 2017, obstetric healthcare professionals in a Dutch region assessed women's GDM risk with a prediction model and counseled those with an increased risk regarding an OGTT.

METHODS

From 2017 to 2018, 865 women were recruited in a multicenter prospective cohort.

RESULTS

In total, 385 women (48%) had an increased predicted GDM risk. Of all women, 78% reported that their healthcare professional discussed their GDM risk. Predicted GDM risks were positively correlated with conducting an OGTT.

CONCLUSION

Implementation of a GDM prediction model resulted in moderate rates of OGTTs performed in general, but high rates in high-risk women. As 25% of women experienced discomfort from the OGTT, a selective screening strategy based on a prediction model with a high detection rate may be an interesting alternative to universal screening.

STUDY COHORT REGISTRATION

Netherlands Trial Register: NTR4143; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4143.

Gestational Diabetes Mellitus-Innovative Approach to Prediction, Diagnosis, Management, and Prevention of Future NCD-Mother and Offspring

Gestational diabetes mellitus (GDM) is the commonest medical complication of pregnancy. The association of GDM with immediate pregnancy complications including excess fetal growth and adiposity with subsequent risk of birth trauma and with hypertensive disorders of pregnancy is well recognized. However, the associations with wide ranges of longer-term health outcomes for mother and baby, including the lifetime risks of obesity, pre-diabetes, and diabetes and cardiovascular disease have received less attention and few health systems address these important issues in a systematic way. This article reviews historical and recent data regarding prediction of GDM using demographic, clinical, and biochemical parameters. We evaluate current and potential future diagnostic approaches designed to most effectively identify GDM and extend this analysis into a critical evaluation of lifestyle and nutritional/pharmacologic interventions designed to prevent the development of GDM. The general approach to management of GDM during pregnancy is then discussed and the major final focus of the article revolves around the importance of a GDM diagnosis as a future marker of the risk of non-communicable disease (NCD), in particular pre-diabetes, diabetes, and cardiovascular disease, both in mother and offspring.

Previous non-diabetic pregnancy with a macrosomic infant - Is it a risk factor for subsequent gestational diabetes mellitus?

AIM

To examine the association between previous pregnancy neonatal birthweight (BW) among non-diabetic women and the rate of gestational diabetes mellitus (GDM) in the subsequent pregnancy.

METHODS

Case control study in a university affiliated medical center from 2005 to 2019. Women who had a singleton pregnancy and two consecutive deliveries in our medical center were included. GDM diagnosis was based on either National Diabetes Data Group or Carpenter and Coustan criteria. Univariate analysis was followed by multivariate logistic regression.

RESULTS

A total of 47,823 women were included. GDM incidence among the subsequent pregnancies was 2.7% (1,312 women). Parturients with GDM had higher mean birthweight in their previous pregnancy compared with parturients without GDM (3336.9 ± 587.4 vs 3229.9 ± 488.2 g, p < 0.001). Women with GDM in the subsequent pregnancy as compared to women without GDM showed higher rates of having previous big neonates: BW ≥ 90% for gestational age, BW ≥ 4000 gr and BW ≥ 4500 g (p < 0.01 for all), 20.2% vs. 10.7%, 9.6% vs 4.5% and 1% vs. 0.3% respectively. Multivariate analysis adjusted for known risk factors for GDM showed that these factors were still independently associated with occurrence of GDM in the subsequent pregnancy 1.7 (1.1-2.5), 1.9 (1.1-3.4), 6.0 (1.6-22.8), respectively.

CONCLUSION

Neonatal BWs in previous pregnancy is associated with increased GDM incidence in the subsequent pregnancy; Women with previous macrosomia should possibly undergo a diagnostic testing.

Stillbirth is associated with increased risk of long-term maternal renal disease: a nationwide cohort study

Background

Stillbirth is a devastating adverse pregnancy outcome that may occur without any obvious reason or may occur in the context of fetal growth restriction, preeclampsia, or other obstetric complications. There is increasing evidence that women who experience stillbirths are at greater risk of long-term cardiovascular disease, but little is known about their risk of chronic kidney disease and end-stage renal disease. We conducted the largest study to date to investigate the subsequent risk of maternal chronic kidney disease and end-stage renal disease following stillbirth.

Objective

To identify whether pregnancy complicated by stillbirth is associated with subsequent risk of maternal chronic kidney disease and end-stage renal disease, independent of underlying medical or obstetric comorbidities.

Study Design/Methods

We conducted a population-based cohort study using nationwide data from the Swedish Medical Birth Register, National Patient Register, and Swedish Renal Register. We included all women who had live births and stillbirths from 1973 to 2012, with follow-up to 2013. Women with preexisting renal disease were excluded. Cox proportional hazard regression models were used to estimate adjusted hazard ratios and 95% confidence intervals for associations between stillbirth and maternal chronic kidney disease and end-stage renal disease respectively. We controlled for maternal age, year of delivery, country of origin, parity, body mass index, smoking, gestational diabetes, preeclampsia, and small for gestational age deliveries. Women who had a history of medical comorbidities, which may predispose to renal disease (prepregnancy cardiovascular disease, hypertension, diabetes, lupus, systemic sclerosis, hemoglobinopathy, or coagulopathy), were excluded from the main analysis and examined separately.

Results

There were 1,941,057 unique women who had 3,755,444 singleton pregnancies, followed up over 42,313,758 person-years. The median follow-up time was 20.7 years (interquartile range, 9.9–30.0 years). 13,032 women (0.7%) had at least 1 stillbirth. Women who had experienced at least 1 stillbirth had a greater risk of developing chronic kidney disease (adjusted hazard ratio, 1.26; 95% confidence interval, 1.09–1.45) and end-stage renal disease (adjusted hazard ratio, 2.25; 95% confidence interval, 1.55–3.25) compared with women who only had live births. These associations persisted after removing all stillbirths that occurred in the context of preeclampsia, and small for gestational age or congenital malformations (for chronic kidney disease, adjusted hazard ratio, 1.33; 95% confidence interval, 1.13–1.57; for end-stage renal disease, adjusted hazard ratio, 2.95; 95% confidence interval, CI 1.86–4.68). There was no significant association observed between stillbirth and either chronic kidney disease or end-stage renal disease in women who had preexisting medical comorbidities (chronic kidney disease, adjusted hazard ratio, 1.13; 95% confidence interval, 0.73–1.75 or end-stage renal disease, adjusted hazard ratio, 1.49; 95% confidence interval, 0.78–2.85).

Conclusion

Women who have a history of stillbirth may be at increased risk of chronic kidney disease and end-stage renal disease compared with women who have only had live births. This association persists independently of preeclampsia, and small for gestational age, maternal smoking, obesity, and medical comorbidities. Further research is required to determine whether affected women would benefit from closer surveillance and follow-up for future renal disease.

Screening for gestational diabetes mellitus - Can we use the 50-g glucose challenge test of the previous pregnancy?

AIM

To assess the association between previous pregnancy glucose challenge test (GCT) result among non-diabetic women and the rate for gestational diabetes mellitus (GDM) in the subsequentpregnancy.

METHODS

Retrospective database study in a university affiliated medical center from 2005 to 2017. Women who had a singleton pregnancy and two consecutive deliveries in our medical center were included. GDM diagnosis was based on either National Diabetes Data Group or Carpenter and Coustan criteria. Univariate analysis was followed by multivariate logistic regression.

RESULTS

A total of 31,861 women were included. GDM incidence among the subsequent pregnancies was 2.1% (670 women). Parturients with GDM had higher mean GCT results in their previous pregnancy compared with parturients without GDM (127.5 ± 28 VS. 98.7 ± 24 mg/dl, p < 0.001). Women with GDMA2 had higher former GCT results than women with GDMA1 (135.9 ± 28 VS. 125.7 ± 27 mg/dl, p < 0.001). Positive association between GCT results in previous pregnancy and rates of GDM in the subsequent pregnancy was noted. Using a GCT value of 107 mg/dl (65th percentile), the area under the receiver-operating curve was 0.79.

CONCLUSION

GCT results in previous pregnancy is associated with GDM incidence in the subsequent pregnancy. Future prospective studies are warranted to better delineate the best screening approach for this subset of patients.

Repeated oral glucose tolerance tests in women at risk for gestational diabetes mellitus

OBJECTIVE

Pregnant women with a negative oral glucose tolerance test (OGTT) between 24-28 weeks as part of risk-based screening for gestational diabetes mellitus (GDM) may develop clinical signs or symptoms suggestive for GDM in the third trimester. We aimed to determine the additional yield of repeating an OGTT to detect missed GDM in this group and assess patient characteristics and indications associated with a positive second OGTT.

STUDY DESIGN

We conducted a retrospective cohort study of women with a negative OGTT between 24-28 weeks of pregnancy in two hospitals in the Netherlands. Patient characteristics, pregnancy outcomes, OGTT results and indications were compared between women with normal (non-GDM) and abnormal (GDM) results of the second OGTT, using the WHO 1999 criteria (fasting glucose ≥7.0 mmol/L or 2 -h post load ≥7.8 mmol/L). We used receiver operating characteristic (ROC) curve analysis to determine cut-offs for fasting and 2 -h glucose values of the index OGTT that were associated with a positive OGTT in the third trimester.

RESULTS

Of 3147 women at risk for GDM, 183 underwent a second OGTT in the third trimester following their regular OGTT at 24-28 weeks. In 43 women (23.5%) GDM was diagnosed based on the second OGTT. A history of GDM was associated with subsequent GDM diagnosis, with an odds ratio of 2.6 (95% CI 1.0-6.3). Both fasting and 2 -h post load glucose values of the index OGTT were significantly higher in women with abnormal OGTT results later in pregnancy. Index OGTT glucose value cut-offs of 4.8 mmol/L (fasting) and 6.5 mmol/L (2 -h) had positive predictive values of 0.32 and 0.47 for a positive OGTT in the third trimester, and negative predictive values of 0.83 and 0.90, respectively. Fetal growth as a clinical symptom for GDM was the most frequent indication for repeating the OGTT, resulting in the diagnosis of GDM in 22.7% of women tested for this indication.

CONCLUSION

Repeating an OGTT after initial negative screening results in additional GDM diagnoses. In case of clinical signs, especially in women with additional risk factors such as a history of GDM or higher index OGTT glucose values, repeating an OGTT could be considered.

Diagnostic Significance of Ultrasonographic Markers and Score in Detection of Gestational Diabetes Mellitus in the Indian Subcontinent

In most countries, only high-risk women are screened for gestational diabetes mellitus (GDM). In addition, a onetime early screening test may miss GDM as it may be diagnosable between 24 and 28 weeks. Thus, it is preferable to have alternative tests to classify women as high risk for GDM and keep them under regular follow-up. A total of 120 women with singleton pregnancies and established maternal and/or pregnancy-related risk factors for GDM and who provided informed consent were subjected to an obstetric ultrasound scan at/or after 24 weeks' gestation followed by administration of a 2-hour 75-g oral glucose tolerance test. Various ultrasound markers were determined/measured. Each ultrasound GDM marker was assigned 1 point to create the ultrasound gestational diabetes screening (UGDS) score. All ultrasound GDM markers positively correlated to the disease (P < 0.0001). The strongest independent predictor of GDM was an immature appearance of placenta (relative risk, 49.09; 95% confidence interval, 7.04-342.28; P < 0.0001). Receiver operator characteristics showed an area under the curve of 96.9%, confirming good ability of the UGDS to discriminate between positive and negative oral glucose tolerance test. A UGDS score of 4, providing diagnostic efficiency of 92%, sensitivity of 93.2%, specificity of 92%, positive predictive value of 85.4%, and negative predictive value of 96.4%, is proposed by this study. This study suggests that ultrasound markers significantly vary in GDM compared with normal pregnancy women and that UGDS is a good predictor of GDM. The UGDS may be considered an adjunct to current screening tools for GDM.

Guidelines for Medical Nutrition Therapy in Gestational Diabetes Mellitus: Systematic Review and Critical Appraisal

BACKGROUND

Medical nutrition therapy is the cornerstone of gestational diabetes mellitus treatment. However, guidelines often present contradictory guidance to health care practitioners.

OBJECTIVE

To systematically review and critically appraise medical nutrition therapy guidelines for treating patients with gestational diabetes mellitus.

DESIGN

We searched Medline, the Cochrane Library, Guidelines International Network, and Google Scholar to retrieve clinical practice guidelines (CPGs) for medical nutrition therapy in gestational diabetes mellitus from professional or governmental organizations, published in English, between January 1, 2007, and November 24, 2018. CPGs were reviewed and appraised using the Appraisal of Guidelines, Research, and Evaluation II instrument.

RESULTS

Of 1,286 retrieved articles, 21 CPGs fulfilled the inclusion criteria. CPGs of the Academy of Nutrition and Dietetics, Diabetes Canada, and Malaysia Health Technology Assessment Section received the greatest overall scores and the highest scores concerning rigor of recommendations development. Many CPGs failed to involve multidisciplinary teams in their development, including patients, and often, dietitians. Applicability of the recommendations was low, lacking facilitators and tools to enhance implementation. Many CPGs demonstrated low editorial independence by failing to disclose funding and competing interests. More medical nutrition therapy recommendations were incorporated in the Academy of Nutrition and Dietetics and Malaysia Health Technology Assessment Section CPGs. The Malaysia Health Technology Assessment Section, Diabetes Canada, Academy of Nutrition and Dietetics, and Endocrine Society guidelines were recommended by the review panel herein without modifications. Overall, the CPGs suggested the consumption of adequate protein and the selection of foods with low glycemic index, divided into three main meals and two to four snacks. Weight gain recommendations were mostly based on the Institute of Medicine body mass index thresholds.

CONCLUSIONS

With few exceptions, the main developmental limitations of the appraised CPGs involved low rigor of recommendations development, lack of multidisciplinary stakeholder involvement, low applicability, and inadequate editorial independence. This indicates a need for developing more clear, unbiased, practical, and evidence-based CPGs.

Diabetes screening in pregnancy failing women in rural Western Australia: An audit of oral glucose tolerance test completion rates

OBJECTIVE

To quantify screening rate for gestational diabetes mellitus and completion of oral glucose tolerance test in rural and remote Western Australia.

DESIGN AND PARTICIPANTS

Retrospective audit of 551 antenatal records from women of 16 years and older without pre-existing diabetes and with singleton pregnancies delivered in 2013.

MAIN OUTCOME MEASURES

Number of women recorded screened for gestational diabetes mellitus in second or third trimester using oral glucose tolerance test or other tests; gestational diabetes mellitus rate.

RESULTS

Only 278 (50.5%) women were screened with oral glucose tolerance test; 113 (20.5%) had no record of any screening related to gestational diabetes mellitus. In a nested mixed-effects logistic regression model, women with a previous gestational diabetes mellitus diagnosis, two or more risk factors (excluding ethnicity) or high-risk gestational diabetes mellitus ethnicity other than Australian Aboriginal were more likely to be screened, while Australian Aboriginal women were less likely to be screened with oral glucose tolerance test. Clinicians reported patient and clinician factors and logistical difficulties as reasons for the oral glucose tolerance test not being completed at their site. Of those screened with oral glucose tolerance test, a high rate of gestational diabetes mellitus was diagnosed (14.7% versus Western Australia state-wide average of 7.4%).

CONCLUSION

Adherence to oral glucose tolerance test screening in rural Western Australia is inadequate for effective screening for gestational diabetes mellitus. Screening was not acceptable or available for a significant proportion of women at risk. Efforts to improve oral glucose tolerance test adherence and exploration of alternative gestational diabetes mellitus screening strategies are required.

Implementation of national screening guidelines for gestational diabetes: A national survey of maternity units in England

AIMS

To describe national implementation of gestational diabetes (GDM) risk-factor based screening guidelines, and barriers to implementation relating to maternal body mass index (BMI).

METHODS

National online survey of NHS Trusts offering maternity services in England. A questionnaire was emailed to clinical staff involved in care of pregnant women assessing compliance with NICE guidelines for risk-factor based screening, BMI thresholds for offering OGTT and barriers to offering OGTT to women with BMI ≥ 30 kg/m2.

RESULTS

Health professionals from 113 (84%) of NHS Trusts in England responded to the survey. Most Trusts (81%) offered OGTT at 26-28 weeks gestation to women with selected risk factors for GDM. However, almost 40% of Trusts were not fully compliant with NICE screening criteria for all risk factors, mainly due to not offering OGTT to women with previous GDM (25% of Trusts), BMI ≥ 30 kg/m2 or ethnic minority groups (22% of Trusts). The main barriers to compliance with the BMI threshold were lack of capacity, resource and funding given the high prevalence of maternal obesity. Forty one percent of Trusts used diagnostic thresholds for GDM which differed from NICE recommendations.

CONCLUSIONS

Additional resources are required for NHS Trusts to fully implement and sustain risk-factor screening, especially for women with previous GDM, BMI ≥ 30 kg/m2 and ethnic minority groups.

Selective Screening Strategies for Gestational Diabetes: A Prospective Cohort Observational Study

AIM

We aimed to develop a prediction model for the diagnosis of gestational diabetes and to evaluate the performance of published prediction tools on our population.

METHODS

We conducted a cohort study on nondiabetic women < 26 weeks gestation at a level 1 clinic in Johannesburg, South Africa. At recruitment, participants completed a questionnaire and random basal glucose and HbA1c were evaluated. A 75 g 2-hour OGTT was scheduled between 24-28 weeks gestation, as per FIGO guidelines. A score was derived using multivariate logistic regression. Published scoring systems were tested by deriving ROC curves.

RESULTS

In 554 women, RBG, BMI, and previous baby ≥ 4000 g were significant risk factors included for GDM, which were used to derive a nomogram-based score. The logistic regression model for prediction of GDM had R2 0.143, Somer's Dxy rank correlation 0.407, and Harrell's c-score 0.703. HbA1c did not improve predictive value of the nomogram at any threshold (e.g,. at probability > 10%, 25.6% of cases were detected without the HbA1c, and 25.8% of cases would have been detected with the HbA1c). The 9 published scoring systems performed poorly.

CONCLUSION

We propose a nomogram-based score that can be used at first antenatal visit to identify women at high risk of GDM.

[Clinical audit of screening for gestational diabetes among 848 pregnant women in 23 maternity units of the Pays de la Loire, 2014]

INTRODUCTION

Guidelines for screening for gestational diabetes mellitus (GDM) were published in 2010. An audit of the maternity units of the Pays de la Loire network sought to determine the adherence rate and to study the factors affecting it in order to propose corrective measures to improve it.

METHODS

The perinatal network in Pays de la Loire provided obstetricians of the 23 participating maternity units with a set of criteria to be collected from the files of women giving birth. The methodology of the audit was designed to enable calculation of the adherence rate overall and according to indications (risk factors, hyperglycemia, and macrosomia): adherence, non-adherence, and over-adherence (screening in the absence of an indication). To obtain around 900 pregnancies, the audit was planned to cover a week of deliveries in June 2014.

RESULTS

The analysis included 848 pregnancies and 872 newborns. Risk factors were found for 46.6% of the women (43.2 to 49.9): 13.2% for maternal age≥35years and 30.8% for BMI≥25kg/m². GDM was diagnosed for 14.6% (12.4 to 17.2). The adherence rate for screening was 45.5% (42.2 to 49.9), the non-adherence rate 27.6% (24.7 to 30.7), and the over-adherence rate 26.9% (24.0 to 30.0). Among the factors potentially associated with adherence, we observed only the second-trimester factor (macrosomia); there was no "professional" effect on adherence criteria. No evidence of overmanagement was observed for the pregnancies/deliveries/newborns with overdiagnosis. Oral glucose tolerance tests were performed in accordance with the guidelines (95.9%). Follow-up of women with GDM by specialists was satisfactory (84.6%).

DISCUSSION

This audit showed that adherence to the guidelines was insufficient in the Pays de la Loire network. The reasons for this are numerous: ignorance of the guidelines, in part due to their relative recency, the change in the blood sugar levels defining GDM (perceived as too low), and the absence of strong evidence about these thresholds from publications and practices in other countries, the need to select women for risk factors, and sometimes the late onset of prenatal care at the maternity unit.

CONCLUSION

In view of this audit, the Perinatal Network of Pays de la Loire must work to improve the knowledge and screening practices for GDM among its professionals, by the repeated dissemination of these guidelines and chart review sessions.

Compliance with National Institute of Health and Care Excellence risk-based screening for Gestational Diabetes Mellitus in nulliparous women

OBJECTIVE

To investigate compliance with risk-based screening for Gestational Diabetes Mellitus (GDM) in a nulliparous cohort.

DESIGN

A retrospective analysis of nulliparous women recruited to a prospective cohort, the Screening for Pregnancy Endpoints (SCOPE) study, was performed. Population included 2428 healthy nulliparous women with singleton pregnancies, recruited within Cork, Ireland; and Manchester, Leeds and London, United Kingdom. Compliance with risk factor screening for GDM was assessed in relation to the following risk factors: obesity, family history of diabetes and increased ethnic risk. GDM was diagnosed using an oral Glucose Tolerance Test (GTT) with locally employed diagnostic criteria. Statistical analysis was performed using Statistical Packages for Social Sciences (SPSS V22). Descriptive statistics are presented for the various baseline characteristics using numbers and percentages. Cross tabulation was used to compare relevant groups. When comparing group distributions Chi-square test was used. p-value <0.05 was considered statistically significant.

RESULTS

In the entire cohort of 2432 women, 27% (650 Women) had one or more identifiable risk factors as defined by National Institute of Health and Care Excellence (NICE) for GDM. Of those that had identifiable GDM risk factors according to the NICE guidelines, 395(60.8%) were appropriately screened. 253 (38.9%) had risk factors but were not screened. 261 (14.6%) had no GDM NICE risk factors but were screened with an oral GTT. Women with a risk factor that were screened with a GTT had an 8.9% (n=34) prevalence of GDM. Of those that were screened but did not have a risk factor 7.7% (n=20) were diagnosed with GDM. Overall, 2% (54 women) of the cohort had a diagnosis of GDM. Ethnicity was the risk factor most likely to be missed (n=55, 66.3%). The GTT test was completed within the recommended gestational window (24-28 weeks) 56.6% (n=371) of the time.

CONCLUSION

This study highlights poor compliance with risk factor screening for GDM in nulliparous women. Further investigation into the underlying reasons is warranted as well as the implications for pregnancy outcome.

TRIAL REGISTRATION NUMBER

ACTRN12607000551493.

Prevalence of Gestational Diabetes and Risk of Progression to Type 2 Diabetes: a Global Perspective

Despite the increasing epidemic of diabetes mellitus affecting populations at different life stages, the global burden of gestational diabetes mellitus (GDM) is not well assessed. Systematically synthesized data on global prevalence estimates of GDM are lacking, particularly among developing countries. The hyperglycemic intrauterine environment as exemplified in pregnancies complicated by GDM might not only reflect but also fuel the epidemic of type 2 diabetes mellitus (T2DM). We comprehensively reviewed available data in the past decade in an attempt to estimate the contemporary global prevalence of GDM by country and region. We reviewed the risk of progression from GDM to T2DM as well. Synthesized data demonstrate wide variations in both prevalence estimates of GDM and the risk of progression from GDM to T2DM. Direct comparisons of GDM burden across countries or regions are challenging given the great heterogeneity in screening approaches, diagnostic criteria, and underlying population characteristics. In this regard, collaborative efforts to estimate global GDM prevalence would be a large but important leap forward. Such efforts may have substantial public health implications in terms of informing health policy makers and healthcare providers for disease burden and for developing more targeted and effective diabetes prevention and management strategies globally.

Relationship between mid-trimester ultrasound fetal liver length measurements and gestational diabetes mellitus

BACKGROUND

The aim of the present study was to investigate the relationship between mid-trimester ultrasound fetal liver length (FLL) and gestational diabetes mellitus (GDM) in a high-risk population.

METHODS

A prospective study was performed in 331 women with singleton pregnancies who were at high risk of GDM and were undergoing a mid-trimester ultrasound examination. The ultrasound scan at 23 weeks gestation was followed by a 100-g oral glucose tolerance test (OGTT) at 24 weeks gestation. Correlations between FLL and OGTT results at different time points were tested. Receiver operating characteristic (ROC) analysis of FLL as a potential prognostic factor for GDM was also performed.

RESULTS

In GDM patients, there was a significant positive correlation (P < 0.01) between FLL and OGTT glycemia immediately before and 60, 120, and 180 min after glucose intake. Mean FLL in GDM was significantly higher than in healthy subjects (41.04 vs 31.09 mm, respectively; P < 0.001). When tested as a potential prognostic factor for GDM, fetal liver measurements showed excellent diagnostic performance. The ROC analysis established a cut-off value of FLL of 39 mm for the prediction GDM, with sensitivity of 71.76%, specificity 97.56%, positive predictive value 91.0%, and negative predictive value 90.9%. The usefulness of FLL measurements was supported by a high area under the ROC curve (90.5%).

CONCLUSION

In conclusion, there is a strong correlation between FLL and OGTT results, with FLL possibly serving as a valid marker for the prediction of GDM in high-risk populations.

The Risk of Gestational Diabetes Mellitus Following Bereavement: A Cohort Study from Denmark and Sweden

BACKGROUND

We investigated whether bereavement of a close family member - a source of severe psychological stress exposure - the year before pregnancy is associated with gestational diabetes mellitus (GDM).

METHODS

We studied pregnant women with livebirths in Denmark during 1994-2008 and with births in Sweden during 1987-2006 (n = 2,569,446). We obtained data on death of women's parents, siblings, and older children, and on demographic and health- and pregnancy-related factors through linkage between nationwide registers.

RESULTS

In multivariable models, death of a close relative the year before pregnancy was associated with a 14% increased odds of GDM [95% confidence intervals (CIs) 1.03, 1.26]. The odds ratios corresponding to the loss of a child, parent, and sibling were 1.51 (95% CI: 1.17, 1.95), 1.12 (95% CI: 1.00, 1.25), and 0.68 (95% CI: 0.40, 1.25), respectively. Deaths due to cardiovascular diseases or diabetes were more closely related to the risk of GDM than other types of deaths. We found no association between unnatural deaths and the risk of GDM.

CONCLUSIONS

Death of a close relative the year before pregnancy was associated with a modestly increased GDM risk. Our findings according to the relative's cause of death suggest that differences in screening for GDM among exposure groups and residual confounding by familial factors related to metabolic and cardiovascular diseases may have contributed to this association. If there is a causal stress effect on GDM in this predominantly Nordic population, it is most likely small.

Gestational diabetes mellitus in Europe: prevalence, current screening practice and barriers to screening. A review

BACKGROUND

Gestational diabetes mellitus is a potentially serious condition that affects many pregnancies and its prevalence is increasing. Evidence suggests early detection and treatment improves outcomes, but this is hampered by continued disagreement and inconsistency regarding many aspects of its diagnosis.

METHODS

The Vitamin D and Lifestyle Intervention for Gestational Diabetes Mellitus Prevention (DALI) research programme aims to promote pan-European standards in the detection and diagnosis of gestational diabetes and to develop effective preventive interventions. To provide an overview of the context within which the programme will be conducted and its findings interpreted, systematic searching and narrative synthesis have been used to identify and review the best available European evidence relating to the prevalence of gestational diabetes, current screening practices and barriers to screening.

RESULTS

Prevalence is most often reported as 2-6% of pregnancies. Prevalence may be lower towards the Northern Atlantic seaboard of Europe and higher in the Southern Mediterranean seaboard. Screening practice and policy is inconsistent across Europe, hampered by lack of consensus on testing methods, diagnostic glycaemic thresholds and the value of routine screening. Poor clinician awareness of gestational diabetes, its diagnosis and local clinical guidelines further undermine detection of gestational diabetes.

CONCLUSIONS

Europe-wide agreement on screening approaches and diagnostic standards for gestational diabetes could lead to better detection and treatment, improved outcomes for women and children and a strengthened evidence base. There is an urgent need for well-designed research that can inform decisions on best practice in gestational diabetes mellitus screening and diagnosis.

Sensitivity and specificity of ultrasonography as a screening tool for gestational diabetes mellitus

OBJECTIVE

To evaluate diagnostic accuracy and efficiency of ultrasound markers of gestational diabetes (GDM) and propose an ultrasound based scoring system suitable for screening (UGDS).

METHODS

110 women with singleton pregnancies and established maternal and/or pregnancy related risk factors for GDM were scanned at/or after 24 weeks gestation followed by administration of a 3 hour 100-gram oral glucose tolerance test (oGTT). A number of ultrasound markers were determined/measured, including fetal adipose subcutaneous tissue, asymmetrical macrosomy, cardiac circumference, cardiac width, and interventricular septum thickness, immature appearance of placenta, intensified breathing movements, polyhydramnios and placental thickness. Each ultrasound GDM marker was assigned one point to create the ultrasound gestational diabetes screening score (UGDS).

RESULTS

All ultrasound GDM markers were positively correlated to the disease P < 0.0001. The strongest independent predictor of GDM was an immature appearance of placenta (RR 40.1 95% CI 5.9-271.0, P < 0.0001). Receiver operator characteristics (ROC) showed an area under the curve of 95.7% confirming good ability of UGDS to discriminate between positive and negative oGTT. We propose a UGDS score of 4 providing sensitivity of 90.9%, and specificity 89.6%.

CONCLUSIONS

This study suggests that UGDS is a good predictor of GDM.

Gestational diabetes mellitus: results from a survey of country prevalence and practices

OBJECTIVE

The association between gestational diabetes mellitus (GDM), perinatal complications and long-term morbidity is gaining increased attention. However, the global burden of GDM and the existing responses are not fully understood. We aimed to assess country prevalence and to summarize practices related to GDM screening and management.

METHODS

Data on prevalence and country practices were obtained from a survey administered to diabetologists, obstetricians and others working on GDM in 173 countries.

RESULTS

GDM prevalence estimates range from <1% to 28%, with data derived from expert estimates, and single-site, multi-site and national prevalence assessments. Seventy-four percent of countries that completed the survey have national GDM guidelines or recommendations. Countries use a variety of screening approaches. In the countries where universal screening is recommended, the percentage of pregnant women screened ranges from 10% to >90%.

CONCLUSIONS

We found large variations in estimated GDM prevalence, but direct comparison between countries is difficult due to different diagnostic strategies and subpopulations. Many countries do not perform systematic screening for GDM, and practices often diverge from guidelines. Countries need to carefully assess the cost and health impact of scaling up GDM screening and management in order to identify the best policy option for their population.

When should screening be performed for gestational diabetes?

AIM

To consider the arguments for screening outside the standard screening period of 24 to 28 weeks of gestation.

MATERIALS AND METHODS

A search of the literature between 1990 and 2010 was performed using the PubMed® and Cochrane® databases. Recommendations from learned societies in diabetology and obstetrics & gynaecology were consulted.

RESULTS

Gestational diabetes mellitus screening is classically recommended between weeks 24 and 28 of pregnancy, the period during which glucose tolerance deteriorates. However, the increasing prevalence of type 2 diabetes in women of childbearing age with risk factors requires earlier screening. Fasting blood glucose should be measured at the fi rst visit during early pregnancy for these patients. The diagnostic threshold is the same as for patients who are not pregnant, i.e. blood glucose > 1.26 g/l. However, the benefit of screening for gestational diabetes during early pregnancy for women with risk factors has not been supported by prospective studies. Therefore oral glucose tolerance testing during early pregnancy is not currently recommended for the detection of gestational diabetes. Screening for gestational diabetes, regardless of the recommended screening policy, must be performed between weeks 24 and 28 of pregnancy. There are no reasons to consider subsequent screening for gestational diabetes at a later stage.