Abstract

Unrecognised gestational diabetes can have an adverse impact on maternal and fetal health. There is a lack of consensus on screening tools and diagnostic criteria. We surveyed practice across all 17 Scottish Maternity units with reference to screening policies and use of new SIGN diagnostic criteria for gestational diabetes and analysed the local impact of adopting this new guidance. Survey results (response from 16 units) confirmed that 2 units have fully adopted both NICE and SIGN criteria and a further 10 units have adopted SIGN diagnostic criteria but not complete NICE screening criteria, and 3 units who have not adopted either.

Locally within Lanarkshire, a prospective audit of 311 women booking in June 2011 confirmed that 33.7% of the pregnant population would qualify for OGTT testing based on NICE guidance. [9.6% ( bmi 30-35), 7.1% ( bmi > 35), 1% (previous macrosomia), 0.3% (previous gestational diabetes), 8% (family history), 0.6% (ethnicity), 7.1% (multiple risk factors)].

A further local retrospective review of 558 OGTT confirmed that the number of positive tests for gestational diabetes based on previous SIGN criteria (fasting>5.5mmol/l and 2 hour>9mmol/l) was 83 (14.9%) and this would increase to 179 (32.1%) based on new criteria (fasting > 5.1mmol/l and 2 hour > 8.5mmol/l)

Implications of adopting new guidance in Lanarkshire would mean an increase in annual OGTT from 609 tests/year to 1685 tests/year and an increase in referral for gestational diabetes from 91/year (1.8% of bookers) to 541/year (9.6%of bookers). This has significant resource implications and presents a challenge for many units to adopt.