OBJECTIVETo evaluate the compliance with self-monitoring of blood glucose (SMBG) and the reliability of diabetes logbooks in women with gestational diabetes mellitus (GDM), as well as the associated determinants and outcomes.RESEARCH DESIGN AND METHODSWe prospectively selected French-speaking women with newly diagnosed GDM who had been referred to our diabetes management program and understood SMBG principles. At the next follow-up visit, we collected SMBG results from glucose meters and logbooks. We analyzed pregnancy outcomes.RESULTSData were analyzed over 13 3 days in 91 women. Only 61.5% had performed 80% of the required tests. Poor compliance was associated with a family history of diabetes, social deprivation, and non-European origin. The average time between pre- and postprandial tests was 141 +/- 20 min, with 46.5% of women performing 80% of postprandial measurements 100-140 min after meals. Inadequate timing was associated with ethnicity and higher HbA(1c) at baseline. A total of 23.1% of women had <90% matched values in diary and meter memory, and a poor concordance was associated with a family history of diabetes. Poor adherence was associated with more preeclampsia (12.2 vs. 1.9%, P = 0.049), and inadequate postprandial test timing with a higher HbA(1c) at delivery (5.3 +/- 0.4 vs. 5.0 +/- 0.3% [34 +/- 2 vs. 31 +/- 2 mmol/mol], P < 0.01), despite more frequent insulin therapy.CONCLUSIONSAlthough women with GDM are considered to be highly motivated, SMBG adherence and reliability are of concern and may be associated with poor gestational prognosis, suggesting that caregivers should systematically check the glucose meter memory to improve GDM management.