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.