Association between maternal glucose and large for gestational outcomes: Real-world evidence to support Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study findings.

AIMS

To compare large for gestational age (LGA) rates by maternal glucose levels in a real-world setting with those in the Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study. To examine the association between fasting plasma glucose (FPG), 1- and 2-h on a 75-g oral glucose tolerance tests (OGTT) and LGA.

METHODS

Pregnancies were categorized according to HAPO thresholds. Category-specific LGA rates were compared to those in HAPO. Categories with glucose thresholds below or above the diagnostic criteria for gestational diabetes mellitus (GDM) were labelled as lower and higher/GDM, respectively. GDM pregnancies were further stratified according to FPG or post-load elevations and logistic regression was used to examine their independent association with LGA.

FINDINGS

In our cohort of 97,032 pregnancies, rates of LGA increased with increasing maternal glucose in lower categories of FPG, 1- and 2-h glucose (trend p < 0.01). However, LGA rates in higher/GDM categories were significantly lower in our study than those in HAPO for 1- and 2-h glucose, but not for FPG. Elevated FPG alone was associated with an almost twofold increase in risk of LGA, while elevated post-load glucose alone was associated with a 20% reduction in risk of LGA, compared to negative OGTT.

CONCLUSIONS

Real-world data confirm the HAPO study findings at lower levels of maternal glycaemia. At higher levels, GDM diagnosis and treatment appear to be effective in reducing rates of LGA in pregnancies with post-load glucose elevations, but not elevated FPG. Elevated FPG is a stronger predictor of LGA than post-load glucose elevations.