Impact of gestational diabetes mellitus diagnosed during the third trimester on pregnancy outcomes: a case-control study

Timing of gestational diabetes diagnosis and progression to type 2 Diabetes: A comparative analysis

AIM

To evaluate and compare the risk of progressing to type 2 diabetes (T2DM) based on the timing of gestational diabetes (GDM) diagnosis during pregnancy.

METHODS

Retrospective analysis of pregnant individuals with gestational diabetes and post-pregnancy follow up. Data sourced from Meuhedet HMO's computerized laboratory system, cross-tabulated with the Israeli National Diabetes Registry. The cohort was divided into normoglycemic, early GDM (diagnosed by fasting plasma glucose 92-125 mg/dL (5.1-6.9 mM) at < 15 weeks), 2nd trimester GDM (diagnosed at 24-28 weeks), and late GDM (diagnosed after 29 weeks). Statistics included univariate analysis followed by survival analysis. Risk was further analyzed for individuals by obesity status.

RESULTS

75,459 entered the analysis: 90 % normoglycemic, 7.9 % early GDM, 1.4 % 2nd trimester GDM, and 0.7 % late GDM. Median post-pregnancy follow-up time was 4.3 (IQR 3.3-5.1). 2nd trimester GDM showed the highest T2DM risk annually after pregnancy. Cox regression analysis, adjusted for confounders, revealed a significantly higher T2DM risk for 2nd-trimester GDM compared to early and late GDM. Late GDM did not confer additional significant T2DM risk. Stratification by obesity status highlighted that early GDM increased the risk of T2DM only in individuals without obesity.

CONCLUSIONS

GDM diagnosis timing significantly impacts T2DM risk. 2nd trimester GDM carries the highest T2DM risk.

The impact on pregnancy outcomes of late-onset gestational diabetes mellitus diagnosed during the third trimester: A systematic review and meta-analysis

BACKGROUND

Evidence is inconsistent regarding the impact of late gestational diabetes mellitus (GDM) on perinatal outcomes.

OBJECTIVES

To evaluate associations of GDM diagnosed in the third trimester (late GDM) with adverse obstetric and neonatal outcomes.

SEARCH STRATEGY

We searched Embase, Medline, and Web of Science from January 1, 1990 to June 16, 2022, for observational studies.

SELECTION CRITERIA

Late GDM was defined as a de novo diagnosis, i.e. after a negative screening for diabetes in the second trimester, and at later than 28 weeks of pregnancy.

DATA COLLECTION AND ANALYSIS

Each abstract and full-text article was independently reviewed by the same two authors. Quality was assessed with the use of the Newcastle-Ottawa Scale. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random effects model.

MAIN RESULTS

Twelve studies were identified as meeting the inclusion criteria, including 3103 patients (571 with late GDM and 3103 controls). Incidences of shoulder dystocia (OR 1.57, 95% CI 1.02-2.42, P = 0.040), 5-minute Apgar score <7 (OR 1.80, 95% CI 1.14-2.86, P = 0.024), cesarean delivery (OR 1.98, 95% CI 1.51-2.60, P < 0.001), and emergent cesarean delivery (OR 1.57, 95% CI 1.02-2.40, P = 0.040) were significantly higher among women with late GDM than among the controls. The groups showed similarity in the rates of fetal macrosomia, large-for-gestational-age fetuses, neonatal hypoglycemia, and hypertensive disorders of pregnancy.

CONCLUSIONS

This meta-analysis showed associations of late GDM with increased adverse perinatal outcomes. Prospective studies should evaluate the impact on perinatal outcomes of repeated third-trimester screening for late GDM.

Is glucose pattern of OGTT associated with late-onset gestational diabetes and adverse pregnant outcomes?

BACKGROUND

The heterogeneity of oral glucose tolerance test (OGTT) patterns during pregnancy remains unclear. This study aims to identify latent OGTT patterns in pregnant women and investigate the high-risk population for late-onset gestational diabetes mellitus (GDM).

METHODS

This study including 17,723 participants was conducted from 2018 to 2021. Latent mixture modeling was used to identify subgroups. Modified Poisson regression was performed to explore the relationship between OGTT patterns and late-onset GDM or adverse perinatal outcomes.

RESULTS

Three distinct glucose patterns, high, medium, and low glucose levels (HG, MG, and LG patterns) were identified. The HG pattern represented 28.5% of the participants and 5.5% of them developed late-onset GDM. A five-fold higher risk of late-onset GDM was found in HG pattern than in LG pattern (relative risk [RR]: 5.17, 95% confidence interval [CI]: 3.38-7.92) after adjustment. Participants in HG pattern were more likely to have macrosomia, large for gestational age, preterm birth, and cesarean deliveries, with RRs of 1.59 (1.31-1.93), 1.55 (1.33-1.82), 1.30 (1.02-1.64) and 1.15 (1.08-1.23), respectively.

CONCLUSION

Three distinct OGTT patterns presented different risks of late-onset GDM and adverse perinatal outcomes, indicating that timely monitoring of glucose levels after OGTT should be performed in pregnant women with HG pattern.

Oral Glucose Tolerance Test Performed after 28 Gestational Weeks and Risk for Future Diabetes-A 5-Year Cohort Study

Gestational diabetes mellitus (GDM) is diagnosed by an oral glucose tolerance test (oGTT), preferably performed at 24 + 0-28 + 6 gestational weeks, and is considered a risk factor for type 2 diabetes (T2DM). In this study, we aimed to evaluate the risk of T2DM associated with abnormal oGTT performed after 28 weeks. We conducted a retrospective cohort study that included parturients with available glucose levels during pregnancy and up to 5 years of follow-up after pregnancy. Data were extracted from the computerized laboratory system of Meuhedet HMO and cross-tabulated with the Israeli National Registry of Diabetes (INRD). The women were stratified into two groups: late oGTT (performed after 28 + 6 weeks) and on-time oGTT (performed at 24 + 0-28 + 6 weeks). The incidence of T2DM was evaluated and compared using univariate analysis followed by survival analysis adjusted to confounders. Overall, 78,326 parturients entered the analysis. Of them, 6195 (7.9%) performed on-time oGTT and 5288 (6.8%) performed late oGTT. The rest-66,846 (85.3%)-had normal glucose tolerance. Women who performed late oGTT had lower rates of GDM and T2DM. However, once GDM was diagnosed, regardless of oGTT timing, the risk of T2DM was increased (2.93 (1.69-5.1) vs. 3.64 (2.44-5.44), aHR (95% CI), late vs. on-time oGTT, p < 0.001 for both). Unlike in oGTT performed on time, one single abnormal value in late oGTT was not associated with an increased risk for T2DM.

Third trimester re-screening for gestational diabetes in morbidly obese women despite earlier negative test can reveal risks for obstetrical complications

AIM

We investigated associations of maternal obesity with late gestational diabetes mellitus (GDM) diagnosis (>34 weeks) in women with previous normal glucose screening, and associations of late GDM with obstetrical outcomes.

METHODS

This retrospective cohort study assessed obstetrical and neonatal outcomes of 238 women with normal (24-28 week) glucose screening results, who underwent late repeat oral glucose tolerance tests (OGTT) (>34 weeks) due to a suspected LGA fetus (54.6%) or polyhydramnios (45.4%). A sub-analysis was performed of outcomes of women with late versus mid-trimester GDM.

RESULTS

The GDM rate in repeat OGTT screening was 22.2% for the total sample, and 33% among women with morbid obesity. Among women with late GDM versus without late GDM, rates were higher for macrosomia, large-for-gestational-age fetus induction of labor, neonatal hypoglycemia, jaundice, and the need for phototherapy. Among women with late GDM, a higher pregestational BMI was associated with adverse maternal and perinatal outcomes. Higher risks for macrosomia and CS due to macrosomia were demonstrated in women with late vs. mid-trimester GDM.

CONCLUSION

Late screening in pregnancy may reveal GDM among women with previous normal glucose screening, particularly among those with late third trimester BMI ≥ 35 kg/m² , GDM in a previous pregnancy or fasting glucose >95 mg/dl. Women diagnosed with GDM at >34 weeks following normal glucose screening at 24-28 weeks are at higher risk for adverse perinatal outcomes. For women with morbid obesity, or suspected macrosomia or polyhydramnios in the late third trimester, and normal glucose screening in the second trimester, retesting should be considered.

Clinical implications of the 100-g oral glucose tolerance test in the third trimester

PURPOSE

The clinical implications of gestational diabetes mellitus (GDM) diagnosed in the third trimester are not well established and controversy continues regarding the performance of diagnostic tests beyond 28-week gestation. This study aimed to evaluate the incidence of abnormal third trimester oral glucose tolerance test (OGTT) results in women at high risk and to compare the obstetric and neonatal outcomes with those of women with normal OGTT results.

METHODS

The study included 372 women who completed late (>29 weeks) 100-g OGTT due to suspected fetal macrosomia, polyhydramnios or a personal risk factor for GDM, diagnosed according to the Carpenter & Coustan criteria. Women with only one abnormal OGTT value were diagnosed with GDM by abnormal glucose follow-up and analyzed separately. Obstetric and neonatal outcomes were compared between the GDM and the non-GDM groups.

RESULTS

GDM was diagnosed in 85/372 (22%) women, including 35 (59.3%) women with one abnormal OGTT value who were later diagnosed with GDM. Of 200 women who had a normal 1-h 50-g glucose challenge test at 24-28 weeks, late GDM was diagnosed in 33 (16.5%). Seventy-six (89.5%) of those with GDM were treated by dietary therapy and 9 (10.5%) by pharmacological therapy. Among women with GDM, large-for-gestational-age fetuses, labor induction and elective cesarean section were more prevalent than for those without GDM. Significant differences were not found between the groups in macrosomia and neonatal outcomes.

CONCLUSIONS

The performance of OGTT in women with risk factors during the third trimester should be considered following further prospective trials.