Elevated fasting vs post‐load glucose levels and pregnancy outcomes in gestational diabetes: a population‐based study. Issue 1 (19th November 2019)

• Record Type: Journal Article
• Authors: Ryan, E. A.; Savu, A.; Yeung, R. O.; Moore, L. E.; Bowker, S. L.; Kaul, P.
• Is Part Of: Diabetic medicine. Volume 37:Issue 1(2020)
• Page Start: 114
• Page End: 122
• Publication Date: 2019-11-19
• Subjects: Diabetes -- Periodicals; 616.462
• DOI: 10.1111/dme.14173
• Languages: English
• ISSNs: 0742-3071

Abstract

Abstract: Aims: To examine the relative association between fasting plasma glucose vs post‐load (1‐h and 2‐h) glucose levels based on the oral glucose tolerance test in pregnancy and large‐for‐gestational‐age and hypertensive disorders of pregnancy outcomes. Methods: All live singleton births between October 2008 and December 2014 in Alberta, Canada were included. Gestational diabetes mellitus was diagnosed using Diabetes Canada criteria. Logistic regression models were used to examine the association between fasting plasma glucose vs post‐load values and large‐for‐gestational‐age infants and hypertensive disorders of pregnancy after adjusting for maternal characteristics and pharmaceutical intervention in gestational diabetes pregnancies. Results: Among 257 547 pregnancies, 208 344 (80.9%) had negative 50‐g glucose challenge tests, 36 261 (14.1%) had negative 75‐g oral glucose tolerance tests, and 12 942 (5.0%) had gestational diabetes based on either elevated fasting plasma glucose ( n =4130, 1.6%) or elevated 1‐h and/or 2‐h oral glucose tolerance test values ( n =8812, 3.4%). Large‐for‐gestational‐age and hypertensive disorders of pregnancy rates were 8.1% and 5.1% in negative glucose challenge test pregnancies, 11.0% and 7.0% in negative oral glucose tolerance test pregnancies, 22.4% and 11.9% in gestational diabetes pregnancies with elevated fasting plasma glucose, and 9.1% and 8% in gestational diabetes pregnancies with elevated post‐load levels, respectively. Among gestational diabetes pregnancies, those with elevated fasting plasma glucose were at higher risk of large‐for‐gestational age (adjusted odds ratio 2.66, 95% CI 2.39–2.96) and hypertensive disorders of pregnancy (adjusted odds ratio 1.51, 95% CI 1.33–1.72) outcomes relative to pregnancies with post‐load glucose elevations only. Fasting plasma glucose remained significantly associated with adverse outcomes in gestational diabetes pregnancies with and without pharmacological intervention. Conclusions: Elevated fasting plasma glucose in women with gestational diabetes is a stronger predictor of large‐for‐gestational‐age and hypertensive disorders of pregnancy outcomes than elevated post‐load glucose. What's new?: Women with gestational diabetes mellitus (GDM) are at an increased risk of developing hypertensive disorders of pregnancy (HDP) and having large for gestational age (LGA) babies. The relative association between fasting plasma glucose (FPG) vs post‐load (1‐ and/or 2‐h) glucose values on the oral glucose tolerance test (OGTT) and adverse pregnancy outcomes in GDM is unknown. Using a large population‐based cohort, we found that LGA and HDP rates were significantly higher in pregnancies with elevated FPG than in those with elevated post‐load glucose levels. FPG is significantly associated with adverse outcomes in GDM pregnancies with and without pharmacological intervention. Fasting hyperglycaemia in GDM is associated with a higher risk of adverse outcomes than elevated post‐load glucose levels. The persistence of adverse outcomes despite treatment suggests that fasting hyperglycaemia may be a marker of some other processes that result in LGA and HDP, and requires further study.