1. Shaheen Mannan Amaju Ikomi
Replacing IADPSG with NICE glucose thresholds for diagnosing gestational diabetes: benefit or burden?
Shaheen Mannan Amaju Ikomi
RCOG WORLD CONGRESS 2016 BIRMINGHAM 20-22nd JUNE

2. Diagnostic thresholds for gdm (mmol/l)
Criteria
Fasting
1 hour
2 hours
WHO 1999 6 -
7.8
IADPSG 2010 5
9.9
8.4
NICE 2015
5.6

3. Background
IADPSG implemented in February 2013 due to macrosomia rate of 30% in IADPSG positive, WHO negative women.
Macrosomia rate in IADPSG positive, WHO negative women normalised to 10.5% post implementation of IADPSG.
Release of NICE threshold in February 2015.

4. Highlighted the potential of ‘falling through the net’ associated with new NICE glucose thresholds.

5. Contextualised the risks by relating this to local contemporary prevalence of GDM

6. Aim
To predict the local impact of converting to NICE glucose thresholds for diagnosis of GDM.
To ascertain the contemporary probability of ‘falling through the net’ in south west Essex.

7. Method
A large retrospective study of 2722, 75g antenatal GTT results. All OGTTs were performed between 2014 and 2015.

8. 189 women (38.2%) would have fallen through the net
Results: n = 2722
Incidence of GDM
IADPSG 2010
495 (18.2%)
NICE 2015
306 (11.2%)
189 women (38.2%) would have fallen through the net

9. Relationship between NICE status and clinical outcomes in 135 IADPSG positive women
Frequency (%)
Medication (%)
Macrosomia (%)
NICE –ve
74 (54.8%)
11 (14.9%)
7 (9.5%)
NICE +ve
61 (45.2%)
16 (26.2%)
8 (13.1%)
NICE –ve had lower medication and macrosomia (>4kg) rate of 14.9% (11/74)

10. Conclusion
Prospective application of IADPSG has normalised macrosomia rate.
Converting to NICE would result in almost 40% of our current case load being left untreated (regressively facing a 30% macrosomia risk).
In relation to the current national drive to reduce the burden of stillbirths due to missed opportunities in detecting gestational diabetes (MBRRACE-UK), this would count as a retrograde step
Adjunctive application of NICE thresholds to IADPSG positive OGTT results may be of predictive value in identifying ‘milder’ gestational diabetics.