ESPE Abstracts

Objective: Typically, infants born to mothers with gestational diabetes mellitus (IOGDM) have greater risks for macrosomia, later obesity and metabolic diseases. However, we have noticed that birth weights of IOGDM have reduced over the last decade even with uniform application of the International Association of Diabetes and Pregnancy Study Group’s (IADPSG) consensus definition. We therefore compared infancy growth outcomes from two IOGDM cohorts born during non-overlapping time periods.

Methods: We compared growth outcomes measured using identical protocols at birth, 3, 12, and 24 months between a ‘recent’ IOGDM cohort (N=139) born in 2011–2013, with an ‘older’ IOGDM cohort (N=98) born in 2001–2009 and also a control population (N=876) all from a single maternity unit. Anthropometry outcomes included weight, length and skinfolds thicknesses. In both cohorts, IOGDM was defined by the same IADPSG threshold of OGTT glucose concentrations: >5.1 mmol/l at 0 minutes, 10.0 mmol/l at 60 minutes, or 8.5 mmol/l at 120 minutes.

Results: At birth, ‘recent’ IOGDM had similar weight and length SDS (0.1±1.0 and −0.1±0.9, respectively) compared to non-GDM controls, but had lower mean skinfolds SDS (−0.4 vs 0.0, P<0.001). The ‘older’ IOGDM demonstrated higher birth weight SDS (0.6±1.0), length SDS (0.2±1.0) and mean skinfolds SDS (0.3±0.9). This ‘older’ IOGDM group had subsequent weight, length, and skinfolds at all time points until 24 months that were greater than controls. By contrast, ‘recent’ IOGDM showed lower growth outcomes, except for 3-months weight. At 24 months, the mean weight and length SDS of recent IOGDM were lower than both ‘older’ IOGDM and control populations (weight 0.0+1.1 vs 0.4+1.1 vs 0.2+1.0, respectively; length 0.3+1.1 vs 0.4+1.1 vs 0.4+1.1, respectively), with lower adiposity (mean skinfold SDS −0.3+0.7 vs 0.2+0.6 and 0.0+0.8, respectively, both P<0.001). Compared to the control and ‘older’ IOGDM populations, mothers of ‘recent’ IOGDM had higher BMI, higher OGTT 60 minutes glucose concentrations, were a more ethnically diverse subgroup, and delivered at earlier gestational ages.

Conclusions: In contrast with an older IOGDM population born 10 years earlier, ‘recent’ IOGDM were not larger at birth than controls, possibly due to enhanced pregnancy glucose management. Furthermore, ‘recent’ IOGDM showed poorer postnatal growth than controls, which could reflect inherent defects in their insulin sensitivity and/or insulin secretion. While avoidance of large size at birth may be advantageous, the longer-term health implications of these changing growth patterns are uncertain.