Risk factors for prolonged mechanical ventilation in critically pregnant women: a retrospective observational study

Background Prolonged mechanical ventilation (MV) is associated with increased morbidity and mortality in critically ill pregnant women.This study aimed to identify risk factors associated with the duration of MV in critically ill pregnant women using clinical and laboratory parameters. Methods We conducted a retrospective analysis of pregnant and postpartum women admitted to the intensive care unit(ICU) between January 1, 2019 and April 30, 2025. Patients were stratified into two groups based on MV duration (≤ 24 hours vs. >24 hours). Risk factors were analyzed using multifactorial logistic regression. Results Among 621 enrolled patients, 354(57%) required MV for ≤ 24 hours,and 267(43%) for > 24 hours. Significant intergroup differences were observed in body mass index(BMI), mortality, APACHE II score, patients referred by the external hospitals, estimated blood loss(ml), volume of red blood cell transfusion (RBC), volume of plasma transfusion(l), acute kidney injury(AKI) grading ( P < 0.001 ), and myocardial injury(all P < 0.005 ). Multivariable analysis identified RBC transfusion volume (OR = 2.66, 95% CI: 1.77–3.56; P < 0.001 ), plasma transfusion volume (OR = 7.823, 95% CI: 4.19–11.46; P < 0.001 ), and AKI grading (OR = 13.17, 95% CI: 3.64–22.69; P  = 0.007) as independent risk factors for prolonged MV. Conclusions Greater transfusion requirements for RBCs and plasma, along with more severe AKI,are independent risk factors for prolonged MV in critically pregnant women.Close monitoring and early intervention targeting these factors may improve patient outcomes.