Glucose screening test results in first and early third trimester of pregnancy: is there any correlation?

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.

Prediction of gestational diabetes mellitus in the first trimester, comparison of fasting plasma glucose, two-step and one-step methods: a prospective randomized controlled trial

Our aim was to evaluate and compare the diagnostic performance of three methods commonly used for GDM screening: fasting plasma glucose (FPG), two-step 50 g glucose challenge test (GCT), and 75 g glucose tolerance test (GTT) in a randomized study design to predict GDM in the first trimester and determine the best approach in predicting GDM. In a non-blind, parallel-group prospective randomized controlled study; 736 singleton pregnant women underwent FPG testing in the first trimester and randomly assigned to two groups; two-step 50 g GCT and 75 g GTT. GDM diagnosis was made according to Carpenter-Coustan or ADA (American Diabetes Association) criteria in two-step 50 g GCT and 75 g GTT groups, respectively. Subsequent testing was performed by two-step 50 g GCT at 24-28 weeks for screen negatives. After excluding the women who were lost to follow-up or withdrawn as a result of pregnancy loss, 486 pregnant women were recruited in the study. The FPG, two-step GCT, and one-step GTT methods identified GDM in 25/486 (5.1 %), 15/248 (6.0 %), and 27/238 (11.3 %) women, respectively. Area under ROC curves were 0.623, 0.708, and 0.792, respectively. Sensitivities were 47.17, 68.18, and 87.1 %, respectively. Specificities were 77.37, 100, and 100 %, respectively. Positive predictive values were 20.33, 100, and 100 %, respectively. Negative predictive values were 92.29, 97, and 98.1 %, respectively. Until superior screening alternatives become available, the 75 g GTT may be preferred for GDM screening in the first trimester.