There was widespread hopeful expectation that the HAPO study (published in 2007) would result in uniform protocols and criteria for the detection and classification of hyperglycemia in pregnancy. Some fifteen years later, this expectation remains unfulfilled, with vigorous and sometimes heated "controversy" still surrounding these questions. The HAPO study did not, in itself, propose diagnostic criteria, but HAPO's results helped inform the subsequent consensus process coordinated by IADPSG.
Although the approach of universal 75 gram OGTT testing at 24 - 28 weeks' gestation has been endorsed (with varying degrees of enthusiasm) by many major national and international bodies, dissent persists. Notable points of contention include the recommendation for universal testing (risk factor based testing still recommended, for example, in the UK and Denmark), the use of one - or two - step diagnostic protocols (in particular in North America), the assignment of a GDM "diagnosis" on the basis of a single elevated OGTT value (in particular in the USA) and the IADPSG choice of diagnostic thresholds (fasting 5.1 / 1 hour 10.0 / 2 hour 8.5 mmol/L) which, in particular, lowered the fasting glucose threshold for GDM compared to previous thresholds used in many countries leading to fears of a GDM tsunami.
Recent population based studies suggest than lower glucose diagnostic thresholds do not improve overall pregnancy outcomes on the population level, but a variety of lines of evidence suggest that treatment of women who fall in the "grey zone" - GDM positive on IADPSG criteria but negative on previous criteria - may suffer increased pregnancy complications if untreated and may benefit from active intervention.
Preanalytic and laboratory protocols for glucose measurement have also become a topical issue, with minor variations with accepted laboratory norms, particularly in fasting glucose results, leading to large changes in GDM frequency.
These contentious issues continue to delay any true global consensus and occur on the backdrop of the dual global epidemics of diabetes and obesity, which means, in some countries (e.g. the USA), that the prevalence of impaired glucose metabolism (IFG and IGT) in women of childbearing age greatly exceeds the reported prevalence of GDM. Despite being a non-sequitur, the prevalence of GDM is then considered excessive and unreasonable.
This presentation will attempt to balance these multiple contentious issues and suggest a path forwards on the global HIP / GDM journey.