408 Blood Pressure Control in Patients with Pregestational Diabetes and Perinatal Outcomes

ACOG/SMFM recommends BP < 140/90mmHg for cHTN in pregnancy. A secondary analysis of CHAP suggested BP < 130/80 reduced adverse outcomes for individuals with DM. Data on diabetes type or glycemic control was not presented. We aimed to determine optimal BP goals for patients with pregestational DM and evaluate for differences by diabetes type or glycemic control. Retrospective cohort study of patients with DM and cHTN who entered care < 20wga and had ³ 3 prenatal visits at a single center from 2012-2023. Fetal anomalies, multiple gestations, pregnancy loss < 20wga, and average BP ³ 160/110 were excluded. Individuals were characterized by average BP at visits: < 130/80, 130-139/80-89, and 140-159/90-109. The primary outcome was preeclampsia. Secondary outcomes were PTB, composite neonatal morbidity, and NICU admission. Outcomes were compared between groups and multivariable logistic regression estimated the association between BP and outcomes. ROC curves were constructed for the prediction of preeclampsia by BP. Optimal cutpoints were determined using the Liu method. Of 486 patients with DM and cHTN, 184 (38%) had average BP < 130/80, 201 (41%) < 130-139/80-89, and 101 (21%) 140/90-159/109. Those with higher BP were more likely to use antihypertensives and aspirin. Diabetes type, prepregnancy A1c, and last A1c did not differ. Patients with BP < 130/80 or 130-139/80-89 were less likely to have preeclampsia regardless of diabetes type and prepregnancy A1c (interaction p 0.92 and 0.22). Patients with lower BP were less likely to have PTB, composite neonatal morbidity and NICU admission. When analyzed as continuous measures, SBP and DBP were good predictors of preeclampsia (AUC 0.76 and 0.71) with optimal cutpoints of 129 mmHg and 78 mmHg. For pregnant individuals with pregestational DM and cHTN, antepartum BP control to < 130/80 may be associated with lower odds of preeclampsia, PTB, and neonatal morbidity. Statistically optimal BP cutoffs support the BP goal < 130/80 mmHg for all individuals with pregestational DM regardless of diabetes type and glycemic control.