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 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