Is there a residual risk of large-for-gestational-age infant related to gestational diabetes mellitus when it is treated?

OBJECTIVE

The hyperglycaemia and adverse pregnancy outcomes (HAPO) study, where hyperglycaemia was untreated, showed a continuous association between large-for-gestational-age (LGA) infant and seven increasing categories of fasting plasma glucose (PG), 1-hour and 2-hour PG values after a 75 g oral glucose tolerance test at 24-32 gestational weeks. We evaluated whether the excess risk persisted in the 6th and 7th glucose categories - corresponding to women treated for gestational diabetes mellitus (GDM).

PATIENTS AND METHODS

We included 7,190 women meeting the HAPO criteria, of whom 655 (9.2%) were treated for GDM (dietary education in all; insulin therapy in 150 (20.3%)). We evaluated the adjusted odds ratio (aOR) for each glucose category (reference 1st category) for LGA infant.

RESULTS

The aOR for LGA linearly increased from the 1st to 5th categories of fasting, 1-hour and 2-hour PG. Specifically, the aORs for the 5th category were 2.20 (95% confidence interval 1.41-3.44), 2.25 (1.11-4.59), and 2.51 (1.63-3.85), respectively. The aORs for the 6th category were globally stable at 2.52 (1.46-4.36), 2.87 (1.48-5.54), and 2.47 (1.46-4.16), respectively. The same was true for the 7th category: 1.41 (0.56-3.55), 2.84 (1.03-7.86), and 3.53 (1.77-7.06), respectively.

CONCLUSION

We confirmed the association between increasing PG category and LGA infant in women without GDM. We did not observe a residual risk of LGA infant in women treated for GDM in our hospital, irrespective of elevated fasting, 1-hour, or 2-hour PG diagnosis. The risk of LGA infant was globally similar to that in women with high normal glucose values.