12503 An Observational Study Of The Glycemic Variability In Type 1 Diabetes Mellitus Women Preconception And During Pregnancy And Its Associations With Adverse Maternal And Neonatal Outcomes

Abstract Disclosure: S. Avula: None. A.R. Ankireddypalli: None. K. Tessier: None. E.R. Seaquist: None. Background: Pregnancy in T1 diabetes mellitus (T1DM) women is associated with increased risk of maternal/fetal complications. Despite glycemic optimization during pregnancy in T1DM, offspring are at increased risk for neonatal complications. Aim: To examine glycemic variability by continuous glucose monitor (CGM) preconception and during pregnancy by trimester and assess the association with adverse maternal/fetal outcomes. Methods: This was a retrospective cohort study of pregnant patients with T1DM who used real-time CGM and delivered at a U.S. tertiary center (2012-2023). Multiple gestations, Cystic fibrosis-related diabetes (CFRD), twin or multiple births, and no valid CGM data for at least one trimester were excluded. 63 met the inclusion criteria. The primary outcome was composite neonatal morbidity (CNM), including large or small for gestational age (LGA/SGA), NICU admission, neonatal hypoglycemia, shoulder dystocia, respiratory distress syndrome, APGAR 1 or 5 minutes < 7, prematurity (<37 weeks), intrauterine growth restriction (IUGR), CPAP, and ventilator. We also collected data about maternal outcomes. Results:54 patients (86%) met at least one outcome included in the CNM. 20 patients (32%) were LGA, 3 (5%) were SGA, 32 (51%) premature, 29 (46%) required NICU admission, 44 (70%) had neonatal hypoglycemia, 3 (5%) had shoulder dystocia, 23 (37%) had respiratory distress, 22 (35%) needed CPAP, 3 (5%) were on ventilator, 11 (18%) had APGAR 1 minute <7. Among maternal outcomes, 18 (29%) developed pre-eclampsia, and 46 (73%) had a cesarean delivery. Overall, individuals with neonatal morbidity had a lower target in range (TIR) and higher target above range(TAR), average glucose, standard deviation(SD), and coefficient of variation (CV) compared with those without the primary composite, but statistical significance was seen for average glucose and TAR. For every 5 mg/dl increase in average glucose (mean of the 3-trimester values), there was a 25% increase in odds of neonatal morbidity (OR 1.25; 95% CI 1.04-1.56; p=0.028). There was a significant association between 1st trimester SD and neonatal morbidity (OR 1.11; 95% CI 1.02-1.24; p=0.027). There was a trend toward significance between the 3rd-trimester average blood glucose and neonatal morbidity (OR 1.26; 95% CI 1.02-1.63; p=0.051). Conclusion: In our single-center cohort, we found maternal average glucose and TAR, as well as first trimester SD, were significantly associated with CNM. This confirms that maternal hyperglycemia and demonstrates that first trimester SD are associated with poorer neonatal outcomes. Presentation: 6/1/2024