1238-P: Is Hypoglycemia following Glucose Load Associated with Adverse Neonatal or Maternal Outcomes?

Introduction & Objective: Gestational diabetes (GDM) is typically diagnosed by elevated plasma glucose on a screening 50-gram 1-hour oral glucose challenge test (1H), followed by two elevated values on a diagnostic 100-gram 3-hour glucose tolerance test (3H). Pregnancy outcomes of individuals with hypoglycemia (HG) during a 1H or 3H have not been well-studied. We aimed to evaluate risk of adverse neonatal outcomes (ANO) and adverse maternal outcomes (AMO) in pregnancies including HG on a 1H or 3H.

Methods: In this retrospective cohort study, we examined patients who delivered at two academic centers from January 2021-June 2022. Singleton pregnancies with a 1H and/or 3H done 8-16 weeks before delivery were included. Pregnancies with fetal anomalies, pre-gestational DM, gastric bypass and cystic fibrosis were excluded. HG was defined as <70 mg/dL. Patients with HG on 1H or 3H were compared to patients with normal 1H. The primary outcome was a composite of ANO/AMO. Groups were compared using Kruskal-Wallis and Chi-square tests, as appropriate. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were estimated from logistic-regression models.

Results: The cohort included 2,867 pregnancies: 2,146 with normal 1H, 102 with HG on 1H, and 147 with HG on 3H. Differences in demographic and risk factors between groups included maternal age at delivery, race/ethnicity, pre-pregnancy BMI and pre-diabetes, maternal cardiac disease, and total weight gain in pregnancy. After adjusting for these differences, HG following 1H or 3H was not associated with increased risk of ANO/AMO overall (1H ANO: aOR 1.292 [CI 0.734-2.276]; 1H AMO: aOR 1.077 [CI 0.638-1.819]; 3H ANO: aOR 0.883 [CI 0.574-1.358]; 3H AMO: aOR 0.998 [CI 0.654-1.523]).

Conclusion: In this cohort of singleton pregnancies, HG following glucose load was not associated with increased risk of ANO/AMO overall. HG following glucose load may indicate abnormal glucose metabolism, though its clinical significance in pregnancy is unclear.