The HAPO study (n=23,316) established associations of glucose levels during pregnancy with perinatal outcomes and served as a major part of the basis for revised definitions of gestational diabetes mellitus (GDM). The HAPO FUS evaluated the long term outcomes following untreated GDM defined by IADPSG / WHO / ADIPS criteria in 4697 mothers and 4832 children at a mean of 11.4 years after the index pregnancy.
The primary maternal outcome was a disorder of glucose metabolism (diabetes or pre-diabetes). The primary offspring outcome was being overweight or obese. Multiple additional measures of offspring glucose metabolism and adiposity were evaluated (obesity, body fat %, waist circumference, sum of skinfolds).
Among mother with GDM, 52.3% developed a disorder of glucose metabolism, vs. 20.1% of those without GDM. Amongst offspring of mothers with GDM, 39.5% were overweight or obese vs. 28.6% of offspring of mothers without GDM. For obesity alone, the corresponding rates were 19.1% vs 9.9%.
Among women with GDM by IADPSG criteria, the GDM diagnosis was associated with significantly higher risks for diabetes and pre diabetes with long term follow up. Among children of mothers with GDM vs. those without it, the difference in the primary outcome of childhood overweight + obesity just failed to reach statistical significance after full adjustment including for maternal BMI during pregnancy. However the risk of childhood obesity alone was significant after full adjustment and multiple other measures of adiposity and glucose metabolism were also impaired in this group.