Effect of the IADPSG screening strategy for gestational diabetes on perinatal outcomes in Switzerland

Aims: To evaluate the impact adoption of the International Association of Diabetes and
Pregnancy Study Groups (IADPSG) criteria on prevalence of gestational diabetes mellitus
(GDM) and risks of perinatal outcomes.

Methods: Retrospectively, 155,103 women screened with selective two step criteria in
Switzerland in period 1 (2005–2010) were compared to 170,427 women screened with
IADPSG criteria in period 2 (2012–2017). GDM prevalence over time was established and
multivariable regression used to assess variation in risks for GDM related events and perinatal outcomes.

Results: GDM prevalence increased steadily over both study periods from 1.8% to 9.0%. A
risk reduction of GDM-related events was shown only for women with one or two risk factors for GDM present (relative risk (95% confidence interval)): (0.93 (0.90,0.97), 0.90
(0.83,0.96)). The comparison of perinatal outcomes between the two study periods revealed a significant lower risk for newborns large for gestational age (LGA) (0.93 (0.91–0.95)), preterm delivery (0.94 (0.92–0.97)) and neonatal hypoglycemia (0.83 (0.77–0.90)) in period 2.

Conclusion: The introduction of the IADPSG criteria for the screening of GDM increased
prevalence by threefold with no substantial improvements in GDM related events for
women without risk factors but reduced the risks for LGA, neonatal hypoglycemia and preterm birth.