TOPLINE:

Early antenatal prediabetes was associated with a markedly higher risk for type 2 diabetes (T2D) within the first 6 years postpartum than an early pregnancy A1c level of less than 5.9% with subsequent gestational diabetes.

METHODOLOGY:

• Pregnancies complicated by early antenatal prediabetes are associated with increased rates of adverse pregnancy outcomes, regardless of subsequent gestational diabetes status; however, data comparing the risk for postpartum progression to diabetes following antenatal prediabetes vs gestational diabetes are lacking.
• Researchers conducted a prospective cohort study in New Zealand using linked health records to compare the risk for postpartum diabetes in 355 participants with antenatal prediabetes (median age, 33 years; median A1c level, 6.0%) and 490 participants with gestational diabetes (median age, 32 years; median A1c level, 5.2%).
• Antenatal prediabetes was defined as A1c levels of 5.9%-6.4% at the first antenatal blood screen. The gestational diabetes cohort included those with early antenatal A1c levels of less than 5.9% and subsequent gestational diabetes.
• One of the primary outcomes was a postpartum diagnosis of diabetes; the secondary outcome was lipid profiles stratified by diabetes diagnosis.
• The median follow-up duration was 3.2 years in the antenatal prediabetes cohort and 6.0 years in the gestational diabetes cohort.

TAKEAWAY:

• A1c level was the strongest predictor of progression to T2D; compared with the gestational diabetes cohort, adjusted hazard ratios (HRs) for postpartum T2D increased stepwise across the antenatal prediabetes A1c range, from HR, 4.5 (95% CI, 2.8-7.3) for 5.9% A1c to HR, 16.7 (95% CI, 10.8-25.8) for 6.2%-6.4% A1c (P < .001).
• The estimated 5-year cumulative incidence of T2D in the antenatal prediabetes cohort was 63% (95% CI, 56%-69%) vs 6.4% (95% CI, 4.0%-8.8%) in the gestational diabetes cohort.
• Lipid profiles varied significantly by diabetes subtypes; the mean triglyceride levels were significantly lower in patients with glucokinase monogenic diabetes (53.1 mg/dL) than in those with T2D (183.4 mg/dL; P = .012) or no diabetes (165.6 mg/dL; P = .013).

IN PRACTICE:

“Intervening during early pregnancy provides a unique opportunity to potentially improve maternal and offspring health outcomes and to reduce health inequities. [A1c] measurement at booking is a low-cost, accessible tool with strong predictive value for postpartum diabetes,” the authors wrote.

SOURCE:

The study was led by Ruth C.E. Hughes, Christchurch Women’s Hospital, Christchurch, New Zealand. It was published online in Diabetes Care.

LIMITATIONS:

The New Zealand glucose tolerance test criteria for gestational diabetes were higher than the International Association of Diabetes and Pregnancy Study Groups criteria, and postpartum diabetes screening relied almost exclusively on A1c levels. Data on family history or concurrent autoimmune disease were not collected. Screening for type 1 and monogenic diabetes was clinician-dependent, which may have led to underdiagnosis. 

DISCLOSURES:

One author received a summer studentship grant from the New Zealand Society for the Study of Diabetes. No other potential conflicts of interest relevant to this article were reported.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.