Foetal outcome in gestational diabetes in south Indians

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.

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.

The association between gestational diabetes and stillbirth: a systematic review and meta-analysis

AIMS/HYPOTHESIS

Controversy exists over whether gestational diabetes increases the risk of stillbirth. The aim of this review was to examine the association between gestational diabetes and stillbirth.

METHODS

We performed searches of the published literature to May 2021. Study selection and data extraction were performed in duplicate by independent reviewers. Meta-analyses of summary measures were conducted using random-effect models for cohort and case-control studies separately. The study protocol was registered in PROSPERO (registration ID CRD42020166939).

RESULTS

From 9981 citations, 419 were identified for full-text review and 73 met inclusion criteria (n = 70,292,090). There was no significant association between gestational diabetes and stillbirth in cohort studies (pooled OR 1.04 [95% CI 0.90, 1.21]; I² 86.1%) or in case-control studies (pooled OR 1.57 [95% CI 0.83, 2.98]; I² 94.8%). Gestational diabetes was associated with lower odds of stillbirth among cohort studies presenting with an adjusted OR (pooled OR 0.78 [95% CI 0.68, 0.88]; I² 42.7%). Stratified analyses by stillbirth ≥28 weeks' gestation, studies published prior to 2013 and studies identified as low quality demonstrated a significantly higher odds of stillbirth in meta-regression (p = 0.016, 0.023 and 0.005, respectively). Egger's test for all included cohort studies (p = 0.018) suggests publication bias for the main meta-analysis.

CONCLUSIONS/INTERPRETATION

Given the substantial heterogeneity across studies, there are insufficient data to define the relationship between stillbirth and gestational diabetes adequately. In the main analyes, gestational diabetes was not associated with an increased risk of stillbirth. However, heterogeneity across studies means this finding should be interpreted cautiously.

Screening and diagnosis of gestational diabetes in India: a systematic review and meta-analysis

AIMS

Although diabetes is rapidly increasing in India, there is no national consensus on best practices for screening, diagnosis, and management of gestational diabetes mellitus (GDM). The goal of this study was to systematically review the literature for studies reporting the prevalence and screening and diagnostic methods for gestational diabetes in India.

METHODS

We searched MEDLINE, Embase, and POPLINE for studies on screening for GDM in India. We included English-language full reports and conference abstracts of cross-sectional studies, prospective, and retrospective cohorts that reported the screening method and prevalence of GDM. We performed descriptive analysis on all studies and meta-analysis, meta-regression, and subgroup meta-analysis on studies with medium or low risk of bias.

RESULTS

We included 64 studies reporting 90 prevalence estimates. Prevalence estimates ranged from 0 to 41.9%. Subset meta-analyses showed that the IADPSG diagnostic criteria found significantly more GDM cases (prevalence = 19.19% [15.5, 23.6], p < 0.05) than the WHO 1999 criteria (10.13% [8.17, 12.50]) and DIPSI criteria (7.37% [5.2, 10.16]). Studies that compared the IADPSG and WHO 1999 criteria showed poor positive agreement (33-79%). Studies specifying time of GDM diagnosis showed that patients (11-60%) develop GDM as early as the first trimester, but many GDM cases (16-40%) are missed if screened only at first visit.

CONCLUSIONS

In India, prevalence estimates of GDM vary substantially by diagnostic criteria. When evaluating screening and diagnostic criteria for GDM, providers should consider their patients' needs and correlate screening criteria with pregnancy outcomes.

Pre-pregnancy Obesity as a Modifier of Gestational Diabetes and Birth Defects Associations: A Systematic Review

Objective Inconsistent findings of associations between gestational diabetes mellitus (GDM) and birth defects suggest unaccounted confounders may underlie the actual basis for such associations. We conducted a systematic review to assess observed associations between GDM and birth defects and the extent to which these could be explained by pre-pregnancy obesity. Methods Using a combination of search terms for GDM and birth defects, we searched PubMed, Scopus, CINAHL, and ClinicalTrials.gov for human-based studies published through September 2013. Studies were eligible for inclusion if they included information on maternal diabetes status, method of diagnosis of GDM, and assessment of birth defects. Twenty-four of 768 potential articles were included. We collected information on study design, location and period, method of determination of diabetes status, types of birth defects, and measures of association reported. Results There was no evidence for consistent association of GDM with birth defects, with the exception of a weak association between GDM and congenital heart defects. When stratified by maternal pre-pregnancy BMI, an association between GDM and congenital heart defects and between GDM and neural tube defects was evident only in women with both GDM and pre-pregnancy obesity. Conclusions for Practice Our findings suggest reported associations between GDM and birth defects may be due, in part, to undiagnosed metabolic disorders associated with obesity, such as pregestational diabetes mellitus, rather than GDM. These findings highlight the need for increased efforts for pre-pregnancy screening for undiagnosed diabetes and awareness of the importance of weight management among women of childbearing age with obesity.

Masked hypoglycemia in pregnancy

BACKGROUND

Hypoglycemia is a major hindrance for optimal glycemic control in women with gestational diabetes mellitus (GDM) on insulin. In the present study, masked hypoglycemia (glucose <2.77mmol/L for ≥30 min) was estimated in pregnant women using a continuous glucose monitoring (CGM) system.

METHODS

Twenty pregnant women with GDM on insulin (cases) and 10 age-matched euglycemic pregnant women (controls) between 24 and 36 weeks gestation were recruited. Both groups performed self-monitoring of blood glucose (SMBG) and underwent CGM for 72 h to assess masked hypoglycemia. Masked hypoglycemic episodes were further stratified into two groups based on interstitial glucose (2.28-2.77 and ≤2.22 mmol/L).

RESULTS

Masked hypoglycemia was recorded in 35% (7/20) of cases and 40% (4/10) of controls using CGM, with an average of 1.28 and 1.25 episodes per subject, respectively. Time spent at glucose levels between 2.28 and 2.77 mmol/L did not differ between the two groups (mean 114 vs 90 min; P = 0.617), but cases spent a longer time with glucose ≤2.2 mmol/L. Babies born to women with GDM were significantly lighter than those born to controls (2860 vs 3290 g; P = 0.012). There was no significant difference in birth weight within the groups among babies born to women with or without hypoglycemia.

CONCLUSION

Euglycemic pregnant women and those with GDM on insulin had masked hypoglycemia. Masked hypoglycemia was not associated with adverse maternal or fetal outcomes. Therefore, low glucose levels in the hypoglycemic range may represent a physiologic adaptation in pregnancy. This response is exaggerated in women with GDM on insulin.

A comparison of fasting plasma glucose and glucose challenge test for screening of gestational diabetes mellitus

Glucose challenge test (GCT) has been used as an effective screening test for gestational diabetes mellitus (GDM), though it has its own limitations. Hence, we assessed the effectiveness of fasting plasma glucose (FPG) as a simpler alternative procedure. A prospective study was done in 500 pregnant women with gestational age between 22 and 37 weeks. FPG, GCT and GTT were performed in all patients using the glucose oxidase/peroxidase method. The overall sensitivity and specificity of GCT were 75.0% and 92.0%, respectively and the corresponding values for FPG were 88.8% and 95.2%. The positive predictive value and negative predictive value were 42.2% and 97.9% for GCT and 59.2% and 99.1% for FPG, respectively. We conclude that FPG can be used as an effective screening tool for gestational diabetes mellitus.

The burden of diabetes mellitus during pregnancy in low- and middle-income countries: a systematic review

BACKGROUND

Little is known about the burden of diabetes mellitus (DM) in pregnancy in low- and middle-income countries despite high prevalence and mortality rates being observed in these countries.

OBJECTIVE

To investigate the prevalence and geographical patterns of DM in pregnancy up to 1 year post-delivery in low- and middle-income countries.

SEARCH STRATEGY

Medline, Embase, Cochrane (Central), Cinahl and CAB databases were searched with no date restrictions.

SELECTION CRITERIA

Articles assessing the prevalence of gestational diabetes mellitus (GDM), and types 1 and 2 DM were sought.

DATA COLLECTION AND ANALYSIS

Articles were independently screened by at least two reviewers. Forest plots were used to present prevalence rates and linear trends calculated by linear regression where appropriate.

MAIN RESULTS

A total of 45 articles were included. The prevalence of GDM varied. Diagnosis was made by the American Diabetes Association criteria (1.50-15.5%), the Australian Diabetes in Pregnancy Society criteria (20.8%), the Diabetes in Pregnancy Study Group India criteria (13.4%), the European Association for the Study of Diabetes criteria (1.6%), the International Association of Diabetes and Pregnancy Study Groups criteria (8.9-20.4%), the National Diabetes Data Group criteria (0.56-6.30%) and the World Health Organization criteria (0.4-24.3%). Vietnam, India and Cuba had the highest prevalence rates. Types 1 and 2 DM were less often reported. Reports of maternal mortality due to DM were not found. No geographical patterns of the prevalence of GDM could be confirmed but data from Africa is particularly limited.

CONCLUSION

Existing published data are insufficient to build a clear picture of the burden and distribution of DM in pregnancy in low- and middle-income countries. Consensus on a common diagnostic criterion for GDM is needed. Type 1 and 2 DM in pregnancy and postpartum DM are other neglected areas.

Incidence of adverse outcomes associated with gestational diabetes mellitus in low- and middle-income countries

BACKGROUND

The contribution of medical conditions such as diabetes mellitus to maternal and neonatal ill-health in low- and middle-income countries is not well documented.

OBJECTIVES

To ascertain the incidence of adverse outcomes associated with gestational diabetes mellitus (GDM) in these countries.

SEARCH STRATEGY

Electronic databases were searched between 1990 and 2011.

SELECTION CRITERIA

Observational, experimental, and quasi-experimental studies reporting adverse outcomes associated with GDM in mothers and their infants in low- and middle-income countries were included.

DATA COLLECTION AND ANALYSIS

Titles and abstracts were screened, and full-text articles were independently assessed by at least 2 reviewers. Characteristics of studies were tabulated and quality assessment performed. Median and interquartile range (IQR) were computed for each adverse outcome.

MAIN RESULTS

25 articles were included from an initial 1282 citations. High median incidences of cesarean (43.8%; IQR, 34.9%-65.9%), neonatal jaundice (17.1%; IQR, 8.5%-22.9%), and macrosomia (17.0%; IQR, 8.3%-32.5%) were reported in women with GDM.

CONCLUSIONS

The high incidence of some complications of GDM is a concern and may indicate poorer care for women with GDM in low-resource settings. The wide IQRs found indicate uncertainty about the burden of GDM in these settings.

Major congenital malformations in women with gestational diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

The risk of major congenital malformations (MCM) is increased in women with pregestational diabetes mellitus (PGDM). Whether this risk is increased in gestational diabetes mellitus (GDM) is still debated. The aim of this study was to perform a systematic review (and meta-analysis) of major congenital malformations in women with gestational diabetes versus a reference population.

METHODS

We conducted a MEDLINE search (1 January 1995 to 31 December 2009) of original studies reporting data on major congenital malformations in women with gestational diabetes and a reference group. Information on pregestational diabetes was collected when available. Two investigators considered studies for inclusion and extracted data; discrepancies were solved by consensus. Meta-analysis tools were used to summarize results. MOOSE and PRISMA guidelines were followed.

RESULTS

Two case control and 15 cohort studies were selected out of 3488 retrieved abstracts. A higher risk of major congenital malformations was observed in offspring of women with gestational diabetes with the following relative risk (RR)/odds ratios (OR) and 95% confidence intervals (CI): RR 1.16 (1.07-1.25) in cohort studies and OR 1.4 (1.22-1.62) in case control studies. Risk of major congenital malformations was much higher in offspring of women with PGDM than in those of the reference group: RR 2.66 (2.04-3.47) in cohort studies and OR 4.7 (3.01-6.95) in the single case control study providing information.

CONCLUSION

There is a slightly higher risk of major congenital malformations in women with gestational diabetes than in the reference group. The contribution of women with overt hyperglycemia and other factors could not be ascertained. This risk, however, is much lower than in women with pregestational diabetes.

Determinants of gestational diabetes mellitus: A case control study in a district tertiary care hospital in south India

OBJECTIVE

To study the determinants of Gestational Diabetes Mellitus (GDM).

DESIGN

Case-control study.

SETTING

Sri Avittom Thirunal Hospital, Thiruvananthapuram district, Kerala, South India.

PARTICIPANTS

300 GDM women as cases and 300 age-matched controls.

STUDY VARIABLES

Sociodemographic characteristics, pre-pregnancy Body Mass Index (BMI), menstrual history, obstetric history, infertility history, family history of diabetes in first degree relatives, recurrent urinary tract infection (UTI), and moniliasis.

STATISTICAL ANALYSIS

T-test, Fishers Exact Test, Chi square test, Adjusted Odds Ratio with 95% CI.

RESULTS

Pre-pregnancy BMI >/= 25 (P < 0.001, OR = 2.7), irregular menstrual cycle (P = 0.006), treatment for infertility (P = 0.001, OR = 3.3), family history of diabetes (P = 0.001, OR = 4.5), history of diabetes in mother (P = 0.003), previous pregnancy losses (P = 0.04), past GDM (P = 0.035), prematurity (P = 0.01), pre-eclampsia (P = 0.04), polyhydramnios (P < 0.001, OR = 6.0), UTI (P < 0.001, OR = 3.2), and moniliasis (P < 0.001, OR = 7.6) were significantly associated with present GDM.

CONCLUSION

Early identification of women at risk of GDM and prompt treatment is recommended to prevent complications.

Glucose tolerance in pregnancy in South India: relationships to neonatal anthropometry

BACKGROUND

The incidence of type 2 diabetes is increasing worldwide, most rapidly in developing countries such as India. Exposure as a fetus to maternal gestational diabetes is thought to be a risk factor for developing the disease. This study was set up to determine the incidence of gestational diabetes mellitus in one urban maternity unit in South India and to examine its effect on the offspring's neonatal anthropometry, childhood growth, and glucose/insulin metabolism. This paper reports neonatal outcomes.

METHODS

Seven hundred and eighty five women were recruited consecutively from the antenatal clinic of the Holdsworth Memorial Hospital, Mysore and underwent a 100 g, 3-hr oral glucose tolerance test at 30 +/- 2 weeks gestation. Gestational diabetes was defined using Carpenter and Coustan criteria. The babies were measured in detail at birth.

RESULTS

Mean maternal age and body mass index were 23.6 years and 23.1 kg/m(2). The incidence of gestational diabetes was 6.2%. Mothers with gestational diabetes had babies that were heavier (3339 g compared with 2956 g for non-diabetic mothers) and larger in measurements of fat, muscle, and skeleton. Even in non-diabetic pregnancies, neonatal weight, head circumference, and ponderal index were positively related to maternal fasting glucose concentrations (P < or = 0.05 for all).

CONCLUSIONS

The incidence of gestational diabetes was high in this unselected sample of mothers booking into one urban Indian maternity unit. Community-based studies are required to confirm this. The effect of maternal glucose concentrations on neonatal anthropometry is continuous and extends into the "normal" glycemic range.