Background: Continuous glucose monitoring (CGM) provides far greater detail about fetal exposure to maternal glucose across the 24 hour day, but recommended summary statistics give no dynamic information about the glucose profile across 24 hours.

Aim: To examine whether differences in temporal glucose control occur in women with type 1 diabetes who develop large for gestational age infants (LGA).

Research Design and Methods: CGM data was available from 200 pregnant women (100 CGM intervention; 100 controls) in the CONCEPTT study, at baseline, 24 and 34 weeks gestation. All women were being treated to tight glycemic targets (mean HbA1c 6.4% at 34 weeks gestation). Functional data analysis (FDA) was applied to determine differences in temporal glucose profiles. LGA was defined as birth weight ≥90th percentile adjusted for infant sex, gestational age, maternal BMI, ethnicity and parity.

Results: 122/200 women had a LGA infant (61%). FDA revealed that those women who gave birth to a LGA infant ran a significantly higher glucose (by 9-14mg/dL; 0.5-0.8 mmol/l) for 16.5 hours of the day compared to those women who did not have a LGA infant (see fig).

Conclusion: Women who go on to have LGA infants have significantly higher fetal exposure to glucose across the 24 hour day, despite being treated to tight glucose targets.

E.M. Scott: Advisory Panel; Self; Abbott. Speaker's Bureau; Self; Abbott, Eli Lilly and Company. H.R. Murphy: Advisory Panel; Self; Medtronic MiniMed, Inc. D. Feig: Advisory Panel; Self; Medtronic. Speaker's Bureau; Self; Medtronic. G. Law: None.


JDRF; Canadian Clinical Trials Network; National Institute for Health Research

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