Aim: Pregestational diabetes is associated with adverse outcomes. Preconception care is beneficial but unplanned pregnancy is common. We aimed to determine predictors of outcomes and factors modifiable during pregnancy in women with pregestational diabetes. Methods: Retrospective analysis of pregnancies complicated by pregestational diabetes at a tertiary center from 2010–2022. Baseline characteristics, longitudinal glycemic, weight and microvascular complication assessment per trimester, and outcomes were collected and binary logistic regression performed. Results: Of 445 pregnancies, 116 (25%) had type 1 diabetes. Mean age was 32.6 ± 5.8 years with prepregnancy BMI 30.0 ± 7.0 kg/m2. The cohort was diverse with 315 (71%) of non-Caucasian ethnicity and 141 (32%) in the most disadvantaged socioeconomic quintile. Planned pregnancy comprised 147 (43%). Women with type 1 compared to type 2 diabetes had increased preeclampsia (28 [26%] vs 48 [15%], p=0.02), preterm (46 [39%] vs 66 [20%], p<0.001), large for gestational age (LGA) (57 [49%] vs 82 [25%], p<0.001), neonatal hypoglycemia (53 [46%] vs 117 [37%], p=0.047), respiratory distress (47 [42%] vs 65 [20%], p<0.001) and neonatal intensive care admission (NICU) (48 [41%] vs 84 [26%], p=0.003). Small for gestational age was more common in type 2 diabetes (5 [4%] vs 32 [10%], p=0.045). Adjusting for diabetes type and baseline features, HbA1c>6.5% in 1st and >6% in 2nd and 3rd trimesters and >15% insulin decrease in 3rd trimester were associated with preeclampsia, 3rd trimester HbA1c>6% an independent predictor (OR 4.7) irrespective of 1st trimester HbA1c. Excessive gestational weight gain (GWG) (OR 3.4) and 3rd trimester HbA1c>6% (OR 3.6), irrespective of 1st trimester HbA1c, were independent predictors of LGA. Third trimester HbA1c>6% was associated with NICU (OR 3.7). Conclusion: Type 1 and 2 diabetes have distinct risk profiles for adverse outcomes. Early and late pregnancy glycemic control and GWG are modifiable targets during pregnancy. Disclosure Y.J.Rhou: None. N.Cheung: None. S.Padmanabhan: None.

Background: Dexamethasone improves COVID-outcomes. Detailed glycemic profile for patients receiving dexamethasone for COVID-is lacking. Methods: Our hospital recommends routine blood glucose monitoring for patients with COVID-receiving dexamethasone 6mg daily. Subjects without prior history of diabetes admitted in a non-critical care setting over a 1-month period were identified and evaluated. The primary outcome was hyperglycemia post-dexamethasone, defined as glucose ≥10mmol/L. Results: Of 277 subjects (52% male, age 52±18 yrs, weight 90±26 kg, 7% with newly diagnosed diabetes [HbA1c ≥6.5%]) , hyperglycemia post-dexamethasone occurred in 51%, with peak glucose 12.4±2.3 (mean 2.2 tests/day) . Glucose excursions peaked 7-9 hours post-dexamethasone (figure) . Hyperglycemic subjects were older (58±17 vs. 45±7 yrs, p<0.001) , had higher HbA1c (6.1±1.0 vs. 5.6±0.9%, p<0.001) , higher initial venous glucose (6.7±1.7 vs. 6.0±1.5mmol/L, p<0.001) , lower initial eGFR (80±18 vs. 84±15mL/min/m2, p=0.02) , higher initial CRP (969±640 vs. 791±558nmol/L, p=0.01) and greater mortality (7.7 vs. 1.5%, p=0.01) . Age, HbA1c and CRP were independent predictors of hyperglycemia. Conclusions: Dexamethasone led to hyperglycemia in half of patients without prior diabetes admitted with COVID-19, with peak occurring 7-9 hours after dexamethasone. Older age, higher HbA1c and initial CRP predicted development of hyperglycemia. Disclosure Y.J.Rhou: None. A.Hor: None. M.Wang: None. Y.Wu: None. D.R.Chipps: None. N.Cheung: None.