Screening for gestational diabetes in Tuscany, Italy. A population study

Abstract

Aims: According to current Italian guidelines, only women at higher risk of gestational diabetes (GDM) are eligible for receiving a glucose tolerance test (OGTT) during pregnancy. This study evaluates the compliance to national guidelines, additionally proposing an algorithm able to identify women with GDM.

Methods: The study included 23,270 pregnant women aged >15yr, resident in Tuscany, a region in central Italy, delivering in year 2015, identified by certificates of care at delivery. Eligibility to screening was evaluated by fulfillment to regional guidelines recommending a 2-h-75g-OGTT only in presence of risk factors. Additionally, a validated algorithm is proposed to diagnose GDM from regional administrative databases.

Results: Glucose tolerance was tested in 79.2% of women. Eligibility criteria were fulfilled in 55.6% of OGTT performers and in 40.2% of those who didn't perform any OGTT. Performers' rate increased with age, body weight, higher education degree and in those followed by a well defined clinical setting. Housewives and students had a lower chance of receiving an OGTT. Algorithm identified GDM in 11% of women, ranging from 14% among eligible and 7% among non-eligible ones.

Conclusion: Selective screening for GDM is not being currently applied in Tuscany. Despite the percentage of eligible women by national guidelines was 55%, the rate of those who performed the screening was about 80%, with a 40% of low risk women continuing to be screened. Moreover, GDM rate, calculated by algorithm, was relatively large (7%) among non-eligible women, suggesting the need of universal glucose screening to adequately capture all GDM cases.

Keywords: Gestational diabetes; OGTT; Population study; Prevalence; Screening.