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

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.

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.

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.

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.