CGM derived indicators of glycaemic control
A CGM (iPro2, Medtronic) was worn to continuously measure interstitial
glucose concentrations across 7 days at 28- and 35-weeks gestation (Sept
2018 to July 2020; n= 57) and Freestyle Libre, Abbott (January 2022 to
March 2022; n= 3) for 7 days at 28-30-, and 35-37 weeks’ gestation. The
CGM was inserted into the subcutaneous layer on the posterior 1/3 of the
upper limb. As per standard-care SMBG and calibration for iPro CGMs,
women recorded capillary glucose concentrations four times daily and
entered into the CareLink Pro App (discontinued) or provided a hard copy
to researchers. Glycaemic variability [Mean Absolute Glucose (MAG) and
SD] was analysed using the EasyGV spreadsheet (Oxford University, UK).
Mean nocturnal glucose was calculated from 00:00 – 05:00 and 3 h
postprandial glucose was calculated from main meal times. Incremental
area under the curve (iAUC) was calculated using the trapezoid method.