Abstract 4371611: Timing Matters: Hypertensive Pregnancy Outcomes by Admission Day

Introduction: Chronic hypertension (CHTN) in pregnancy is defined as blood pressure ≥140/90 mmHg diagnosed before pregnancy or before 20 weeks’ gestation. Clinically distinct from gestational hypertension or preeclampsia. CHTN affects 0.9 to1.5% of pregnancies, with incidence rising due to increasing rates of advanced maternal age, obesity, and comorbid conditions. Pregnant patients with CHTN face elevated risks for maternal and fetal complications. The weekend effect refers to observed increases in adverse outcomes for patients admitted to the hospital on weekends compared to weekdays. Research Question: Our study investigates whether the timing of hospital admission day is associated with higher rates of several maternal morbidity (SMM) among pregnant patients with CHTN. Methods: This retrospective cohort study used the 2022 data from the National Inpatient Sample, including females (≥15 years &<54 years) hospitalized with a secondary diagnosis of maternal hypertension complicating pregnancy, identified via ICD10 codes. The primary outcome was SMM, a validated metric encompassing 21 distinct and unexpected complications during the peripartum period. The secondary outcomes included intubation, cesarean section, length of stay, and total hospitalization charges. Multivariate logistic regression adjusted for age, race, payer, community and hospital characteristics. Results: There were 96,605 hospitalizations with patients with hypertension complicating pregnancy in 2022. Weekend admissions comprised 15.24% (n=14,725) of the cohort. Weekend patients were older (32.3 vs. 31.9 years). A total of 6,540 patients experienced SMM. The SMM rate for patients admitted on the weekend was 9% vs 6% on weekdays (P = 0.0000, CI 1.346-1.802). There were no differences in intubation rates, but there were differences in cesarean rates with a 46.46% lower odds of receiving a cesarean if admitted on the weekend (P=0.000, CI 0.492-0.58.3). Weekend admits had no differences in mean charges (P=0.297, CI -$2341 to $714). Patients admitted on weekends had similar mean length of stays as weekday (p=0.56, CI -0.22 days to 0.12 days) Conclusion: Patients admitted on weekends had worse SMM outcomes compared to weekday. This may be due to reduced staffing levels and limited specialist availability. Weekend admissions had lower odds to undergo a cesarean, which may be due to fewer scheduled procedures. Understanding this relationship is clinically relevant and warrants further study.