Pregnancy Outcomes in Type 2 Diabetes: a systematic review and meta-analysis

Naomi S Clement; Ahmad Abul; Rachel Farrelly; Helen R Murphy; Karen Forbes; Nigel A B Simpson; Eleanor M Scott

doi:10.1016/j.ajog.2024.11.026

Pregnancy Outcomes in Type 2 Diabetes: a systematic review and meta-analysis

Am J Obstet Gynecol. 2024 Dec 9:S0002-9378(24)01176-1. doi: 10.1016/j.ajog.2024.11.026. Online ahead of print.

Authors

Naomi S Clement¹, Ahmad Abul², Rachel Farrelly³, Helen R Murphy⁴, Karen Forbes³, Nigel A B Simpson⁵, Eleanor M Scott³

Affiliations

¹ Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK. Electronic address: naomi.clement@nhs.net.
² Division of Surgical and Interventional Sciences, University College London, London, UK.
³ Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK.
⁴ Norwich Medical School, University of East Anglia, Norwich, UK.
⁵ Department of Women's and Children's Health, University of Leeds, Leeds, UK.

PMID: 39662865
DOI: 10.1016/j.ajog.2024.11.026

Abstract

Objective: Type 2 diabetes (T2D) now accounts for the majority of pre-existing diabetes affecting pregnancy in the UK. Our aim was to determine its impact on pregnancy outcomes compared to type 1 diabetes (T1D), gestational diabetes (GDM) and non-diabetes pregnancies.

Data sources: PubMed was searched 1 January 2009-2024.

Study eligibility criteria: Cohort observational studies reporting original data on at least one of the primary outcomes in ten or more T2D pregnancies were eligible for inclusion. Comparative diabetes and non-diabetes pregnancies were also collected.

Study appraisal and synthesis methods: Primary outcomes included congenital anomalies, stillbirths, neonatal and perinatal mortality, birthweight, rates of large for gestational age (LGA), small for gestational age (SGA) and macrosomia. PROSPERO ID CRD42023411057.

Results: 47 studies were analysed. The number of pregnancies in each analysis varied depending on the available data from the outcome being analysed but ranged from 723 to 4,469,053 pregnancies. When compared with T1D pregnancies, T2D were more likely to have SGA babies as well as greater neonatal and perinatal mortality (OR 2.29, 95% CI 1.12 - 4.67; OR 1.53 95% CI 1.20 to 1.94 and OR 1.31 95% CI 1.07 to 1.61 respectively). When compared with GDM, T2D were more likely to have babies with congenital anomalies (OR 1.91, 95% CI 1.04 - 3.50), LGA (OR 3.49, 95% CI 2.49 to 4.89), neonatal mortality (OR 3.96, 95% CI 3.38 to 4.64) and stillbirth (OR 16.55, 95% CI 5.69 to 48.11). In comparison to non-diabetic pregnancy, T2D were more likely to have babies with congenital anomalies (OR 1.76, 95% CI 1.11 - 2.79), LGA (OR 2.79, 95% CI 1.93 to 4.04), perinatal mortality (OR 4.18, 95% CI 2.91 to 6.01) and stillbirth (OR 7.27, 95% CI 3.01 to 17.53).

Conclusions: T2D pregnancies are associated with a greater perinatal mortality than other forms of diabetes in pregnancy. Given its increasing prevenance, greater awareness of the adverse pregnancy outcomes associated with T2D is needed, by both healthcare providers and policy makers, to improve care.

Keywords: Diabetes in Pregnancy; congenital malformations; perinatal mortality; pregnancy outcomes; stillbirth; type 2 diabetes.

Publication types

Review