Pregnancy Outcomes of Women Additionally Diagnosed as Gestational Diabetes by the International Association of the Diabetes and Pregnancy Study Groups Criteria

Neonatal outcomes according to different glucose threshold values in gestational diabetes: a register-based study

BACKGROUND

Mild hyperglycaemia is associated with increased birth weight but association with other neonatal outcomes is controversial. We aimed to study neonatal outcomes in untreated mild hyperglycaemia using different oral glucose tolerance test (OGTT) thresholds.

METHODS

This register-based study included all (n = 4,939) singleton pregnant women participating a 75 g 2-h OGTT in six delivery hospitals in Finland in 2009. Finnish diagnostic cut-offs for GDM were fasting ≥ 5.3, 1 h ≥ 10.0 or 2-h glucose ≥ 8.6 mmol/L. Women who did not meet these criteria but met the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria (fasting 5.1-5.2 mmol/L and/or 2-h glucose 8.5 mmol/L, n = 509) or the National Institute for Health and Clinical Excellence (NICE) criteria (2-h glucose 7.8-8.5 mmol/L, n = 166) were considered as mild untreated hyperglycaemia. Women who met both the Finnish criteria and the IADPSG or the NICE criteria were considered as treated GDM groups (n = 1292 and n = 612, respectively). Controls were normoglycaemic according to all criteria (fasting glucose < 5.1 mmol/L, 1-h glucose < 10.0 mmol/L and 2-h glucose < 8.5 mmol/L, n = 3031). Untreated mild hyperglycemia groups were compared to controls and treated GDM groups. The primary outcome - a composite of adverse neonatal outcomes, including neonatal hypoglycaemia, hyperbilirubinaemia, birth trauma or perinatal mortality - was analysed using multivariate logistic regression.

RESULTS

The risk for the adverse neonatal outcome in untreated mild hyperglycemia was not increased compared to controls (adjusted odds ratio [aOR]: 1.01, 95% confidence interval [CI]: 0.71-1.44, using the IADPSG criteria; aOR: 1.05, 95% CI: 0.60-1.85, using the NICE criteria). The risk was lower compared to the treated IADPSG (aOR 0.38, 95% CI 0.27-0.53) or the treated NICE group (aOR 0.32, 95% CI 0.18-0.57).

DISCUSSION

The risk of adverse neonatal outcomes was not increased in mild untreated hyperglycaemia compared to normoglycaemic controls and was lower than in the treated GDM groups. The OGTT cut-offs of 5.3 mmol/L at fasting and 8.6 mmol/L at 2 h seem to sufficiently identify clinically relevant GDM, without excluding neonates with a risk of adverse outcomes.

Gestational diabetes mellitus and adverse maternal and perinatal outcomes in twin and singleton pregnancies: a systematic review and meta-analysis

OBJECTIVE

This study aimed to assess the risk of adverse maternal and perinatal complications between twin and singleton pregnancies affected by gestational diabetes mellitus and the respective group without gestational diabetes mellitus (controls).

DATA SOURCES

A literature search was performed using MEDLINE, Embase, and Cochrane from January 1980 to May 2023.

STUDY ELIGIBILITY CRITERIA

Observational studies reporting maternal and perinatal outcomes in singleton and/or twin pregnancies with gestational diabetes mellitus vs controls were included.

METHODS

This was a systematic review and meta-analysis. Pooled estimate risk ratios with 95% confidence intervals were generated to determine the likelihood of adverse pregnancy outcomes between twin and singleton pregnancies with and without gestational diabetes mellitus. Heterogeneity among studies was evaluated in the model and expressed using the I2 statistic. A P value of <.05 was considered statistically significant. The meta-analyses were performed using Review Manager (RevMan Web). Version 5.4. The Cochrane Collaboration, 2020. Meta-regression was used to compare relative risks between singleton and twin pregnancies. The addition of multiple covariates into the models was used to address the lack of adjustments.

RESULTS

Overall, 85 studies in singleton pregnancies and 27 in twin pregnancies were included. In singleton pregnancies with gestational diabetes mellitus, compared with controls, there were increased risks of hypertensive disorders of pregnancy (relative risk, 1.85; 95% confidence interval, 1.69-2.01), induction of labor (relative risk, 1.36; 95% confidence interval, 1.05-1.77), cesarean delivery (relative risk, 1.31; 95% confidence interval, 1.24-1.38), large-for-gestational-age neonate (relative risk, 1.61; 95% confidence interval, 1.46-1.77), preterm birth (relative risk, 1.36; 95% confidence interval, 1.27-1.46), and admission to the neonatal intensive care unit (relative risk, 1.43; 95% confidence interval, 1.38-1.49). In twin pregnancies with gestational diabetes mellitus, compared with controls, there were increased risks of hypertensive disorders of pregnancy (relative risk, 1.69; 95% confidence interval, 1.51-1.90), cesarean delivery (relative risk, 1.10; 95% confidence interval, 1.06-1.13), large-for-gestational-age neonate (relative risk, 1.29; 95% confidence interval, 1.03-1.60), preterm birth (relative risk, 1.19; 95% confidence interval, 1.07-1.32), and admission to the neonatal intensive care unit (relative risk, 1.20; 95% confidence interval, 1.09-1.32) and reduced risks of small-for-gestational-age neonate (relative risk, 0.89; 95% confidence interval, 0.81-0.97) and neonatal death (relative risk, 0.50; 95% confidence interval, 0.39-0.65). When comparing relative risks in singleton vs twin pregnancies, there was sufficient evidence to suggest that twin pregnancies have a lower relative risk of cesarean delivery (P=.003), have sufficient adjustment for confounders, and have lower relative risks of admission to the neonatal intensive care unit (P=.005), stillbirths (P=.002), and neonatal death (P=.001) than singleton pregnancies.

CONCLUSION

In both singleton and twin pregnancies, gestational diabetes mellitus was associated with an increased risk of adverse maternal and perinatal outcomes. In twin pregnancies, gestational diabetes mellitus may have a milder effect on some adverse perinatal outcomes and may be associated with a lower risk of neonatal death.

Maternal and fetal outcomes of pregnancies associated with single versus double abnormal values in 100 gr glucose tolerance test

Purpose of the study

Comparing maternal and fetal outcomes in pregnancies associated with single versus double abnormal values in 100 gr oral glucose tolerance test (OGTT).

Methods

This cohort study was performed in Arash women's Hospital, Tehran, Iran from 2019 to 2020. Patients with normal fasting blood sugar (FBS) tests were divided into two groups according to their OGTT results. The first group had a single abnormal value in their OGTT and the second group showed two abnormal values. Both groups were followed regularly until the end of pregnancy.

Results

Our results showed higher rates of macrosomia (birth of newborns weighed over 4 kg) and the need for pharmacological treatment for the management of GDM in the second group (P = 0.05). There were no differences between the two groups in terms of other maternal (polyhydramnios, shoulder dystocia, operative vaginal delivery, atony, postpartum bleeding, cesarean delivery, preeclampsia, and IUFD) and fetal outcomes (Apgar score, seizure, NICU admission, and hypoglycemia in the first 24 h).

Conclusion

We found no significant differences between pregnant women with single and double abnormal values in 100 gr OGTT regarding maternal and neonatal outcomes, except for macrosomia and need for pharmaceutical treatment.

Review of the Screening Guidelines for Gestational Diabetes Mellitus: How to Choose Wisely

Currently, there is no international unanimity regarding the timings, the optimal cut-off points, and standardized methods of screening or diagnosis of gestational diabetes mellitus (GDM). The screening guidelines and recommendations for GDM evolved over time; concise information has been presented here in the review. We searched electronic databases for various guidelines for screening of GDM in PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), Embase, Cochrane, Google Scholar, Scopus, Guidelines International Network (GIN library), National Guidelines Clearinghouse (NGC); Web sites of relevant organizations; and trial registries. The mesh headings derived after reviewing the articles and were used to further search the articles are: ("Screening Guidelines GDM" or "Screening Criteria for GDM") and ("Glucose Intolerance in Pregnancy" or "Gestational Diabetes Mellitus"). The articles published from 1960 till December 2022 were included. Key outcomes included the prevalence of GDM is 14.6% according to the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria and 13.4% according to Diabetes in Pregnancy Study Group India (DIPSI) criteria, making the DIPSI criterion a cost-effective method for low-resource settings. The IADPSG) criterion diagnoses and treats GDM earlier, thus reducing the complications associated with GDM in the mother and newborn. The IADPSG criteria at a cut-off of ≥140 mg/dL have a sensitivity of 81% and specificity of 93%, whereas the World Health Organization (2013) criteria at the same cut-off has a lower sensitivity of 59% and specificity of 81%. The risk factors of having GDM are family history, history during past pregnancy, medical history, multiple current pregnancies, and raised hemoglobin A1c. The screening guidelines have been developed by different organizations and institutions over the years. The guidelines with the threshold values for screening and their standardization for detecting GDM in Indian mothers are yet to be established.

Risk factors for postpartum urinary incontinence: The impact of early-onset and late-onset Gestational Diabetes Mellitus in a nested case-control study

BACKGROUND

Gestational Diabetes Mellitus (GDM) and many other clinical variables have been associated with postpartum urinary incontinence (UI). However, the data are still restricted, and no study explored early- or late-onset GDM as a risk factor for this condition. We aimed to identify independent risk factors for postpartum UI, focusing on GDM and its early or late onset.

METHODS

A nested case control derived from the Diamater cohort study included 517 pregnant women who submitted to a planned C-section and followed by 6-18 months after delivery according to the timing of GDM diagnosis: early-onset GDM (before 20 weeks) and late-onset GDM(24-28 weeks) and the occurrence of UI.

RESULTS

Univariate analysis showed that the risk for 6-18 months postpartum UI was 49% higher in non-Caucasian ethnicity (1.49,1.02-2.18), 3,3 times higher in previous bariatric surgery [3.37,1.36-8.21], 39% higher in GDM women (1.39,1.01-1.93), and 5% higher for each BMI score in prepregnancy (1.05, 1.03-1.08) and at the end of pregnancy (1.05,1.02-1.08). Multivariate logistic regression analysis indicates that prepregnancy BMI was the only independent factor associated with the 6-18 months postpartum UI (adj 1.05, 95 %CI 1.02-1.08, P <.001). After stratifying, a second univariate and multivariate analysis were done according to the prepregnancy BMI cutoff score of 25. Thus, a significant association between GDM and postpartum UI in prepregnancy overweight women (RR: 1.91; 95 %CI 1.25-2.90, P =.003) and no association between GDM and 6-18 months postpartum UI in normal prepregnancy BMI (RR: 0.78, 95 %CI 0.39-1.54, P =.482) were found. After multivariate regression, the early-onset-GDM remained the unique independent adjusted risk factor for 6-18 months postpartum UI analysis (adjRR 2.15, 95 %CI 1.33-3.46, P =.002).

CONCLUSION

After a planned C-section, we observed a 6-18 months postpartum UI higher occurrence after GDM, either in early-onset GDM or late-onset GDM. In addition, being overweight (BMI > 25) among women with early-onset GDM was associated with postpartum UI.

Update on gestational diabetes and adverse pregnancy outcomes

PURPOSE OF REVIEW

To explore the recent literature concerning the effect of gestational diabetes (GDM) on adverse pregnancy outcomes (APO).

RECENT FINDINGS

Literature search on PubMed, Medline and British Journal of Obstetrics and Gynaecology was conducted using keywords. Search fields were filtered down to include articles from 2019 onwards. GDM is common during pregnancy and is on the rise because of increasing in obesity rates. GDM tended to show an increased risk of APO compared with non-GDM. Treatment of these pregnancies tended to improve these outcomes, particularly for LGA and macrosomia. Additional factors such as prepregnancy BMI and gestational weight gain (GWG) were shown to influence risk. More studies are needed to determine the true effect on postpartum haemorrhage (PPH) and induction of labour (IOL).

SUMMARY

The review agrees with the findings from previous studies and adds to the current literature. Early intervention to manage glycaemic control and GWG may help improve these outcomes. Public health strategies that tackle obesity rates will help to reduce prepregnancy BMI and, therefore, rates of GDM.

Effects of early standardized management on the growth trajectory of offspring with gestational diabetes mellitus at 0-5 years old: a preliminary longitudinal study

To explore the application value of early standardized management in the delivery of neonates of pregnant women with gestational diabetes mellitus (GDM). Parturient diagnosed with GDM and their offspring were selected in our hospital from January 1, 2015 to December 31, 2017 to underwent early standardized management. Non-GDM pregnant women and their offspring were selected as the control group. The growth and development of children aged 0-5 years in the two groups were longitudinally followed up, and the mixed linear model was used to evaluate and compare the growth trajectories. There was no significant difference in height and weight between the two groups at 1 year old (P > 0.05), but the BMI of the GDM group was significantly higher than that in the control group. After 1 year of age, both groups of offspring were similar in height, weight, and BMI, and these similarities persisted at 2, 3, 4, and 5 years of age. After controlling for covariates, the weight, length/height of the two groups of children were slightly different in the growth trajectories between 0-1 years old, 1-2 years old, 2-3 years old, 3-4 years old, and 4-5 years old with no statistical significance (P > 0.05). Although growth differences between the two groups of children were detected within 1 year of age, there were no significant differences in growth trajectories from 1 to 5 years between two groups, which proved that early standardized management has positive significance.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pregnancy complications in women with pregestational and gestational diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) is a major risk factor for complications of pregnancy. Based on information for all inpatient births in Germany, we assessed the risks for selected pregnancy complications in women with pregestational diabetes mellitus (preDM) or gestational diabetes mellitus (GDM).

METHODS

The underlying data comprised all singleton births contained in the inpatient perinatal medicine quality assurance statistics for the years 2013-2019. The frequencies of premature birth, elevated birth weight (large for gestational age, LGA), cesarean section, transfer of the newborn to the perinatal unit, and stillbirth were stratified by maternal age and diabetes status (preDM, GDM, no DM). Poisson regression was used to calculate the relative risks (RR) with 95% confidence intervals (95% CI) for the whole period and for each individual year in women with preDM or GDM relative to women without DM.

RESULTS

Among the 4 991 275 singleton births included, GDM was documented in 283 210 (5.7%) and preDM in 46 605 (0.93%) cases. GDM was associated with higher RR for premature birth (1.13 [1.12; 1.15]), LGA (1.57 [1.55; 1.58]), cesarean section (1.26 [1.25; 1.27]), and transfer of the newborn (1.54 [1.52; 1.55]). These associations were even stronger in women with preDM: premature birth (2.13 [2.08; 2.18]), LGA (2.72 [2.67; 2.77]), cesarean section (1.62 [1.60; 1.64]), transfer of the newborn (2.61 [2.56; 2.66]). PreDM increased the risk of stillbirth (RR: 2.34 [2.11; 2.59]); GDM was associated with a lower risk (RR: 0.67 [0.62; 0.72]). For women with preDM, the risk of pregnancy complications increased over the study period.

CONCLUSION

GDM and preDM are still associated with elevated risks of pregnancy complications. In the case of preDM, the risks may be attributable to the fact that the hyperglycemia is more severe and is already present before conception. Continuous monitoring should include risk factors in pregnant women and care-relevant aspects.

Predicting the Risk of Insulin-Requiring Gestational Diabetes before Pregnancy: A Model Generated from a Nationwide Population-Based Cohort Study in Korea

BACKGRUOUND

The severity of gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes. We aimed to generate a risk model for predicting insulin-requiring GDM before pregnancy in Korean women.

METHODS

A total of 417,210 women who received a health examination within 52 weeks before pregnancy and delivered between 2011 and 2015 were recruited from the Korean National Health Insurance database. The risk prediction model was created using a sample of 70% of the participants, while the remaining 30% were used for internal validation. Risk scores were assigned based on the hazard ratios for each risk factor in the multivariable Cox proportional hazards regression model. Six risk variables were selected, and a risk nomogram was created to estimate the risk of insulin-requiring GDM.

RESULTS

A total of 2,891 (0.69%) women developed insulin-requiring GDM. Age, body mass index (BMI), current smoking, fasting blood glucose (FBG), total cholesterol, and γ-glutamyl transferase were significant risk factors for insulin-requiring GDM and were incorporated into the risk model. Among the variables, old age, high BMI, and high FBG level were the main contributors to an increased risk of insulin-requiring GDM. The concordance index of the risk model for predicting insulin-requiring GDM was 0.783 (95% confidence interval, 0.766 to 0.799). The validation cohort's incidence rates for insulin-requiring GDM were consistent with the risk model's predictions.

CONCLUSION

A novel risk engine was generated to predict insulin-requiring GDM among Korean women. This model may provide helpful information for identifying high-risk women and enhancing prepregnancy care.

Effect of Different Types of Diagnostic Criteria for Gestational Diabetes Mellitus on Adverse Neonatal Outcomes: A Systematic Review, Meta-Analysis, and Meta-Regression

BACKGROUND

Evidence supporting various diagnostic criteria for diagnose gestational diabetes mellitus (GDM) are consensus-based, needs for additional evidence related to outcomes. Therefore, the aim of this systematic-review and meta-analysis was to assess the impact of different GDM diagnostic-criteria on the risk of adverse-neonatal-outcomes.

METHODS

Electronic databases including Scopus, PubMed, and Web of Sciences were searched to retrieve English original, population-based studies with the universal GDM screening approach, up to January-2020. GDM diagnostic criteria were classified in seven groups and International Association of the Diabetes and Pregnancy Study Groups (IADPSG) was considered as reference one. We used the Mantel-Haenszel method to calculate the pooled odds of events. The possibility of publication bias was examined by Begg's test.

RESULTS

A total of 55 population-based studies consisting of 1,604,391 pregnant women with GDM and 7,770,855 non-GDM counterparts were included. Results showed that in all diagnostic-criteria subgroups, the risk of adverse neonatal outcomes including macrosomia, hyperbilirubinemia, respiratory distress syndrome, neonatal hypoglycemia, neonatal intensive care unit admission, preterm birth, and birth-trauma were significantly higher than the non-GDM counterparts were significantly higher than non-GDM counterparts. Meta-regression analysis revealed that the magnitude of neonatal risks in all diagnostic-criteria subgroups are similar.

CONCLUSION

Our results showed that the risk of adverse-neonatal-outcome increased among women with GDM, but the magnitude of risk was not different among those women who were diagnosed through more or less intensive strategies. These findings may help health-care-providers and policy-makers to select the most cost-effective approach for the screening of GDM among pregnant women.

Gestational diabetes mellitus and adverse pregnancy outcomes: systematic review and meta-analysis

OBJECTIVE

To investigate the association between gestational diabetes mellitus and adverse outcomes of pregnancy after adjustment for at least minimal confounding factors.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Web of Science, PubMed, Medline, and Cochrane Database of Systematic Reviews, from 1 January 1990 to 1 November 2021.

REVIEW METHODS

Cohort studies and control arms of trials reporting complications of pregnancy in women with gestational diabetes mellitus were eligible for inclusion. Based on the use of insulin, studies were divided into three subgroups: no insulin use (patients never used insulin during the course of the disease), insulin use (different proportions of patients were treated with insulin), and insulin use not reported. Subgroup analyses were performed based on the status of the country (developed or developing), quality of the study, diagnostic criteria, and screening method. Meta-regression models were applied based on the proportion of patients who had received insulin.

RESULTS

156 studies with 7 506 061 pregnancies were included, and 50 (32.1%) showed a low or medium risk of bias. In studies with no insulin use, when adjusted for confounders, women with gestational diabetes mellitus had increased odds of caesarean section (odds ratio 1.16, 95% confidence interval 1.03 to 1.32), preterm delivery (1.51, 1.26 to 1.80), low one minute Apgar score (1.43, 1.01 to 2.03), macrosomia (1.70, 1.23 to 2.36), and infant born large for gestational age (1.57, 1.25 to 1.97). In studies with insulin use, when adjusted for confounders, the odds of having an infant large for gestational age (odds ratio 1.61, 1.09 to 2.37), or with respiratory distress syndrome (1.57, 1.19 to 2.08) or neonatal jaundice (1.28, 1.02 to 1.62), or requiring admission to the neonatal intensive care unit (2.29, 1.59 to 3.31), were higher in women with gestational diabetes mellitus than in those without diabetes. No clear evidence was found for differences in the odds of instrumental delivery, shoulder dystocia, postpartum haemorrhage, stillbirth, neonatal death, low five minute Apgar score, low birth weight, and small for gestational age between women with and without gestational diabetes mellitus after adjusting for confounders. Country status, adjustment for body mass index, and screening methods significantly contributed to heterogeneity between studies for several adverse outcomes of pregnancy.

CONCLUSIONS

When adjusted for confounders, gestational diabetes mellitus was significantly associated with pregnancy complications. The findings contribute to a more comprehensive understanding of the adverse outcomes of pregnancy related to gestational diabetes mellitus. Future primary studies should routinely consider adjusting for a more complete set of prognostic factors.

REVIEW REGISTRATION

PROSPERO CRD42021265837.

Risk and Risk Factors for Postpartum Type 2 Diabetes Mellitus in Women with Gestational Diabetes: A Korean Nationwide Cohort Study

BACKGROUND

There are differences in risk and risk factor findings of postpartum type 2 diabetes mellitus (T2DM) after gestational diabetes depending on study design and subjects of previous studies. This study aimed to assess these risk and risk factors more accurately through a population-based study to provide basic data for prevention strategies.

METHODS

This open retrospective cohort included data of 419,101 women with gestational diabetes and matched 1,228,802 control women who delivered between 2004 and 2016 from the South Korea National Health Information Database of the National Health Insurance Service. Following 14 (median 5.9) years of follow-up, the incidence and hazard ratio (HR) of postpartum T2DM were evaluated using Kaplan-Meier curves and Cox proportional regression models.

RESULTS

The incidence and HR of postpartum T2DM in women with gestational diabetes (compared to women without gestational diabetes) after the 14-year follow-up was 21.3% and 2.78 (95% confidence interval [CI], 2.74 to 2.82), respectively. Comorbid obesity (body mass index [BMI] ≥25 kg/m2) increased postpartum T2DM risk 7.59 times (95% CI, 7.33 to 7.86). Significant risk factors for postpartum T2DM were fasting glucose level, BMI, age, family history of diabetes, hypertension, and insulin use during pregnancy.

CONCLUSION

This population-based study showed higher postpartum T2DM risk in women with gestational diabetes than in those without, which was further increased by comorbid obesity. BMI and fasting glucose level were important postpartum risk factors. The management of obesity and glycemic control may be important strategies to prevent the incidence of diabetes after delivery.

Gestational Diabetes Mellitus: Diagnostic Approaches and Maternal-Offspring Complications

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

Postprandial Free Fatty Acids at Mid-Pregnancy Increase the Risk of Large-for-Gestational-Age Newborns in Women with Gestational Diabetes Mellitus

BACKGROUND

To investigate the association between free fatty acid (FFA) level at mid-pregnancy and large-for-gestational-age (LGA) newborns in women with gestational diabetes mellitus (GDM).

METHODS

We enrolled 710 pregnant women diagnosed with GDM from February 2009 to October 2016. GDM was diagnosed by a 'two-step' approach with Carpenter and Coustan criteria. We measured plasma lipid profiles including fasting and 2-hour postprandial FFA (2h-FFA) levels at mid-pregnancy. LGA was defined if birthweights of newborns were above the 90th percentile for their gestational age.

RESULTS

Mean age of pregnant women in this study was 33.1 years. Mean pre-pregnancy body mass index (BMI) was 22.4 kg/m2. The prevalence of LGA was 8.3% (n=59). Levels of 2h-FFA were higher in women who delivered LGA newborns than in those who delivered non-LGA newborns (416.7 μEq/L vs. 352.5 μEq/L, P=0.006). However, fasting FFA was not significantly different between the two groups. The prevalence of delivering LGA newborns was increased with increasing tertile of 2h-FFA (T1, 4.3%; T2, 9.8%; T3, 10.7%; P for trend <0.05). After adjustment for maternal age, pre-pregnancy BMI, and fasting plasma glucose, the highest tertile of 2h-FFA was 2.38 times (95% confidence interval, 1.11 to 5.13) more likely to have LGA newborns than the lowest tertile. However, there was no significant difference between groups according to fasting FFA tertiles.

CONCLUSION

In women with GDM, a high 2h-FFA level (but not fasting FFA) at mid-pregnancy is associated with an increasing risk of delivering LGA newborns.

Maternal Hyperglycemia during Pregnancy Increases Adiposity of Offspring

BACKGROUND

The effect of intrauterine hyperglycemia on fat mass and regional fat proportion of the offspring of mothers with gestational diabetes mellitus (OGDM) remains to be determined.

METHODS

The body composition of OGDM (n=25) and offspring of normoglycemic mothers (n=49) was compared using dualenergy X-ray absorptiometry at age 5 years. The relationship between maternal glucose concentration during a 100 g oral glucose tolerance test (OGTT) and regional fat mass or proportion was analyzed after adjusting for maternal prepregnancy body mass index (BMI).

RESULTS

BMI was comparable between OGDM and control (median, 16.0 kg/m2 vs. 16.1 kg/m2 ). Total, truncal, and leg fat mass were higher in OGDM compared with control (3,769 g vs. 2,245 g, P=0.004; 1,289 g vs. 870 g, P=0.017; 1,638 g vs. 961 g, P=0.002, respectively), whereas total lean mass was lower in OGDM (15,688 g vs. 16,941 g, P=0.001). Among OGDM, total and truncal fat mass were correlated with fasting and 3-hour glucose concentrations of maternal 100 g OGTT during pregnancy (total fat mass, r=0.49, P=0.018 [fasting], r=0.473, P=0.023 [3-hour]; truncal fat mass, r=0.571, P=0.004 [fasting], r=0.558, P=0.006 [3-hour]), but there was no correlation between OGDM leg fat mass and maternal OGTT during pregnancy. Regional fat indices were not correlated with concurrent maternal 75 g OGTT values.

CONCLUSION

Intrauterine hyperglycemia is associated with increased fat mass, especially truncal fat, in OGDM aged 5 years.

Nonalcoholic fatty liver disease and the risk of insulin-requiring gestational diabetes

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases; however, there has been little research into its impact on gestational diabetes mellitus (GDM).

METHODS

This study included 308,095 women registered in the Korean National Health Insurance Service database, who delivered between 2011 and 2015 and received a health examination within 52 weeks before pregnancy. Insulin-requiring GDM was defined as no insurance claims for diabetes mellitus and a fasting blood glucose level of < 126 mg/dL before pregnancy, and initiation of insulin treatment during pregnancy. A fatty liver index (FLI) was calculated using body mass index, waist circumference, and blood triglyceride and γ-glutamyl transferase levels. FLI scores < 30 ruled out hepatic steatosis, while FLI scores ≥ 60 indicated NAFLD.

RESULTS

The prevalence of NAFLD was 0.8% (2355/308,095) and 1984 (0.6%) subjects developed insulin-requiring GDM. FLIs of 30-59 and ≥ 60 were significantly associated with increased risk of insulin-requiring GDM (odds ratio [OR] 3.50; 95% confidence interval [CI] 2.99-4.10; OR 4.19; 95% CI 3.37-5.23), respectively. Further exploration of the association of FLI with GDM across FLI decile categories revealed a steady increase in OR across the categories. The association was more prominent among those without metabolic syndrome.

CONCLUSION

NAFLD in women is an independent risk factor for insulin-requiring GDM.

Fetal Abdominal Obesity Detected At 24 to 28 Weeks of Gestation Persists Until Delivery Despite Management of Gestational Diabetes Mellitus

BACKGROUND

Fetal abdominal obesity (FAO) has been reported to be affected at gestational diabetes mellitus (GDM) diagnosis at 24 to 28 weeks of gestation in older and/or obese women. This study investigated whether the management of GDM improves FAO in GDM subjects near term.

METHODS

Medical records of 7,099 singleton pregnant women delivering at CHA Gangnam Medical Center were reviewed retrospectively. GDM was diagnosed by 100-g oral glucose tolerance test after 50-g glucose challenge test based on Carpenter-Coustan criteria. GDM subjects were divided into four study groups according to maternal age and obesity. FAO was defined as ≥90th percentile of fetal abdominal overgrowth ratios (FAORs) of the ultrasonographically estimated gestational age (GA) of abdominal circumference per actual GA by the last menstruation period, biparietal diameter, or femur length, respectively.

RESULTS

As compared with normal glucose tolerance (NGT) subjects near term, FAORs and odds ratio for FAO were significantly higher in old and/or obese women with GDM but not in young and nonobese women with GDM. For fetuses of GDM subjects with FAO at the time of GDM diagnosis, the odds ratio for exhibiting FAO near term and being large for GA at birth were 7.87 (95% confidence interval [CI], 4.38 to 14.15) and 10.96 (95% CI, 5.58 to 20.53) compared with fetuses of NGT subjects without FAO at GDM diagnosis.

CONCLUSION

Despite treatment, FAO detected at the time of GDM diagnosis persisted until delivery. Early diagnosis and treatment might be necessary to prevent near term FAO in high-risk older and/or obese women.

Estimated impact of introduction of new diagnostic criteria for gestational diabetes mellitus

BACKGROUND

Implementation of new diagnostic criteria for gestational diabetes mellitus (GDM) are still a subject of debate, mostly due to concerns regarding the effects on the number of women diagnosed with GDM and the risk profile of the women newly diagnosed.

AIM

To estimate the impact of the World Health Organization (WHO) 2013 criteria compared with the WHO 1999 criteria on the incidence of gestational diabetes mellitus as well as to determine the diagnostic accuracy for detecting adverse pregnancy outcomes.

METHODS

We retrospectively analyzed a single center Dutch cohort of 3338 women undergoing a 75 g oral glucose tolerance test where the WHO 1999 criteria to diagnose GDM were clinically applied. Women were categorized into four groups: non-GDM by both criteria, GDM by WHO 1999 only (excluded from GDM), GDM by WHO 2013 only (newly diagnosed) and GDM by both criteria. We compared maternal characteristics, pregnancy outcomes and likelihood ratios for adverse pregnancy outcomes.

RESULTS

Retrospectively applying the WHO 2013 criteria increased the cohort incidence by 13.1%, from 19.3% to 32.4%. Discordant diagnoses occurred in 21.3%; 4.1% would no longer be labelled as GDM, and 17.2% were newly diagnosed. Compared to the non-GDM group, women newly diagnosed were older, had higher rates of obesity, higher diastolic blood pressure and higher rates of caesarean deliveries. Their infants were more often delivered preterm, large-for-gestational-age and were at higher risk of a 5 min Apgar score < 7. Women excluded from GDM were older and had similar pregnancy outcomes compared to the non-GDM group, except for higher rates of shoulder dystocia (4.3% vs 1.3%, P = 0.015). Positive likelihood ratios for adverse outcomes in all groups were generally low, ranging from 0.54 to 2.95.

CONCLUSION

Applying the WHO 2013 criteria would result in a substantial increase in GDM diagnoses. Newly diagnosed women are at increased risk for pregnancy adverse outcomes. This risk, however, seems to be lower than those identified by the WHO 1999 criteria. This could potentially influence the treatment effect that can be achieved in this group. Evidence on treatment effects in newly diagnosed women is urgently needed.

The Clinical Characteristics of Gestational Diabetes Mellitus in Korea: A National Health Information Database Study

BACKGROUND

To investigate the clinical characteristics of gestational diabetes mellitus (GDM) in Korea, using a nationwide database.

METHODS

We analyzed 417,139 women who gave birth between 2011 and 2015 using the Korean National Health Information Database. They underwent the Korean National Health Screening Program within one year before pregnancy and were not prescribed drugs for diabetes nor diagnosed with diabetes mellitus before 280 days antepartum. Patients with GDM were defined as those who visited the outpatient clinic more than twice with GDM codes.

RESULTS

The prevalence of GDM was 12.70% and increased with increasing maternal age, prepregnancy body mass index (BMI), waist circumference (WC), and fasting plasma glucose (FPG) (P for trend <0.05). As compared with those aged <25 years, the odds ratio for women with GDM aged ≥40 years were 4.804 (95% confidence interval [CI], 4.436 to 5.203) after adjustment for covariates. Women with prepregnancy BMI ≥30 kg/m2 were at 1.898 times (95% CI, 1.736 to 2.075) greater risk for GDM than those with prepregnancy BMI <18.5 kg/m2. Women with WC of ≥95 cm were at 1.158 times (95% CI, 1.029 to 1.191) greater risk for GDM than women with WC of less than 65 cm. High FPG, high income, smoking, and drinking were associated with an elevated risk of GDM.

CONCLUSION

The prevalence of GDM in Korean women increased up to 12.70% during 2011 to 2015. These data suggest the importance of GDM screening and prevention in high-risk groups in Korea.

Effect of the IADPSG screening strategy for gestational diabetes on perinatal outcomes in Switzerland

AIMS

To evaluate the impact adoption of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria on prevalence of gestational diabetes mellitus (GDM) and risks of perinatal outcomes.

METHODS

Retrospectively, 155,103 women screened with selective two step criteria in Switzerland in period 1 (2005-2010) were compared to 170,427 women screened with IADPSG criteria in period 2 (2012-2017). GDM prevalence over time was established and multivariable regression used to assess variation in risks for GDM related events and perinatal outcomes.

RESULTS

GDM prevalence increased steadily over both study periods from 1.8% to 9.0%. A risk reduction of GDM-related events was shown only for women with one or two risk factors for GDM present (relative risk (95% confidence interval)): (0.93 (0.90,0.97), 0.90 (0.83,0.96)). The comparison of perinatal outcomes between the two study periods revealed a significant lower risk for newborns large for gestational age (LGA) (0.93 (0.91-0.95)), pre-term delivery (0.94 (0.92-0.97)) and neonatal hypoglycemia (0.83 (0.77-0.90)) in period 2.

CONCLUSION

The introduction of the IADPSG criteria for the screening of GDM increased prevalence by threefold with no substantial improvements in GDM related events for women without risk factors but reduced the risks for LGA, neonatal hypoglycemia and preterm birth.

Triglyceride and glucose index and the risk of gestational diabetes mellitus: A nationwide population-based cohort study

AIMS

Pre-pregnancy insulin resistance is one of the main pathophysiologies of gestational diabetes mellitus (GDM). Triglyceride-glucose (TyG) index is a marker of insulin resistance. We aimed to evaluate the association between pre-pregnancy TyG index and GDM in primipara women.

METHODS

A total of 380,208 women who underwent a Korean national health screening exam within 2 years before their first delivery, between January 1, 2012 and December 31, 2015, were included. The TyG index was calculated as ln [triglyceride (mg/dL) × fasting plasma glucose (mg/dL)/2].

RESULTS

Among the 380,208 primipara women, 17,239 women were diagnosed with GDM (4.53%). Multivariate logistic regression analysis adjusted for risk factors showed a higher odds ratio of 1.73 for GDM (95% CI 1.65-1.81) in the highest quartile than that in the lowest quartile. A 1-SD increase in the TyG index increased the risk of GDM (31%) and GDM requiring insulin therapy (82%) in the fully adjusted model. A 1-unit increase in the TyG index significantly increased the risk of GDM and GDM requiring insulin treatment by 1.81 and 3.69 times, respectively.The impact of a high TyG index on the risk of GDM was more profound in the subjects aged ≥ 35 years, with obesity, with impaired fasting glucose, who are current smokers, and with a family history of diabetes mellitus.

CONCLUSIONS

Increased pre-pregnancy TyG index is associated with a risk of GDM. Elevation of the TyG index may be an early marker of GDM.

Prepregnancy smoking and the risk of gestational diabetes requiring insulin therapy

The relationship between maternal smoking and gestational diabetes mellitus (GDM) is inconclusive. We investigated whether prepregnancy smoking is a risk factor for insulin-requiring GDM in Korean women. Using the National Health Insurance Service database, 325,297 women who delivered between 2011 and 2015 and who received a health examination within 52 weeks before pregnancy were included. Insulin-requiring GDM was defined as no claims for diabetes mellitus and a fasting blood glucose level of < 126 mg/dL before pregnancy, and initiation of insulin treatment during pregnancy. Smoking status was identified in a self-reported questionnaire completed during the health examination. There were 2,114 women (0.65%) with GDM who required insulin therapy. Compared with nonsmokers, the fully adjusted odd ratios (ORs) of former smokers and current smokers for insulin-requiring GDM were 1.55 (95% confidence interval [CI] 1.27–1.90) and 1.73 (1.42–2.09), respectively. The ORs (95% CIs) of insulin-requiring GDM among women who reported ≤ 2, 2–≤ 4, 4–≤ 6, 6–≤ 8, 8–≤ 10, and > 10 pack-years of smoking were 1.50 (1.22–1.84), 1.71 (1.31–2.22), 1.60 (1.13–2.26), 1.97 (1.14–3.40), 2.34 (1.22–4.51), and 2.29 (1.25–4.22), respectively, compared with nonsmokers (P for trend < 0.001). This association was similar in women with or without obesity and abdominal obesity. In conclusions, women who smoke have a significantly higher risk of GDM requiring insulin therapy, which may be proportional to the cumulative exposure to smoking. Cessation of smoking should be emphasized in women of childbearing age for the prevention of GDM.

Gestational diabetes mellitus diagnosed at 24 to 28 weeks of gestation in older and obese Women: Is it too late?

Aim/Background

The prevalence of elderly pregnancy and maternal obesity is increasing worldwide. In old and obese women, metabolic derangement affecting fetal growth might be present earlier than the diagnosis of gestational diabetes mellitus (GDM) or even before pregnancy. We thus investigated whether GDM diagnosed at 24–28 weeks of gestation had already affected fetal abdominal growth and, if so, whether elderly pregnancy and/or maternal obesity aggravate fetal abdominal obesity.

Methods

We retrospectively reviewed the medical records of 7820 singleton pregnant women who had been universally screened using a 50-g glucose challenge test (GCT) at 24–28 weeks of gestation, and underwent a 3-h 100-g oral glucose tolerance test (OGTT) if GCT were ≥140mg/dl. GDM and normal glucose tolerance (NGT) were diagnosed using the Carpenter-Coustan criteria. Fetal abdominal obesity was investigated by assessing the fetal abdominal overgrowth ratios (FAORs) of the ultrasonographically estimated gestational age (GA) of abdominal circumference per actual GA by the last menstruation period, biparietal diameter or femur length, respectively. Fetal abdominal overgrowth was defined as FAOR ≥ 90^th percentile. The subjects were divided into four study groups: group 1 (age < 35 years and pre-pregnancy body mass index [BMI] < 25 kg/m²), group 2 (age < 35 years and ≥ 25), group 3 (age ≥ 35 years and BMI < 25), and group 4 (age ≥ 35 years and ≥ 25).

Results

The overall prevalence of GDM was 5.1%, with old and obese group 4 exhibiting the highest prevalence (22.4%). FAORs were significantly higher in the fetus of those with GDM than in the NGT subjects. But, in the subgroup analysis, only old and nonobese group 3 and old and obese group 4 with GDM exhibited significantly higher FAORs than the NGT subjects. Also, risk of fetal abdominal overgrowth was increased in group 3 and 4 subjects with GDM but not in young and nonobese group 1 GDM. The risk of fetal abdominal overgrowth significantly increased with maternal age >35 years, pre-pregnancy BMI >20kg/m², and HbA1c >37.7 mmol/mol (5.6%). In multivariate analyses, maternal age and HbA1c were significantly associated with FAORs.

Conclusion

GDM diagnosed at 24–28 weeks of gestation already affected fetal abdominal obesity in older and/or obese women, but not in younger and nonobese women. Our data suggest that selective screening and appropriate intervention of GDM earlier than 24–28 weeks of gestation might be necessary for high-risk old and/or obese women.