A Predictive Model for Treatment Effectiveness in Severe Primary Immune Thrombocytopenia during Pregnancy: A Retrospective Study in a Tertiary Critical Maternity Referral Center

Abstract

Objectives The study aimed to identify factors influencing the severity of primary immune thrombocytopenia (ITP) during pregnancy, develop a predictive model for treatment response, and report maternal and neonatal outcomes associated with severe ITP. Design A retrospective analysis was conducted on 155 pregnancies with severe ITP between January 2018 and April 2023 at a tertiary critical maternity referral center in Shanghai, China. Participants/Materials The study included 155 pregnancies diagnosed with severe ITP, divided into groups based on the lowest platelet count (<30×109/L vs. 30-50×109/L) and first-line treatment response (Non-response vs. Response). Setting The study was conducted at Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, a tertiary critical maternity rescue referral center. Methods Clinical characteristics and outcomes were compared between groups. A multivariable logistic regression model was used to identify factors associated with the severity of ITP. A prediction model for treatment response was established using LASSO-logistic regression and internally validated. Results ITP severity was found to be correlated with low maximum amplitude (MA) of thrombelastography (TEG) (OR 5.43, 95% CI 1.48 to 16.00, p=0.002), bleeding events (OR 4.91, 95% CI 1.62 to 14.86, p=0.005), and low reticulocytes (OR 2.40×10-7, 95% CI 1.06×10-13 to 0.55, p=0.04). Of the 118 patients who received first-line therapy, 52 (44%) responded. The dataset was randomly split into a training (N=99) and test (N=23) set with a ratio of 8:2. A predictive nomogram was created and internally validated showing good discrimination. The model yielded an area under receiver operating characteristic curve (ROC) of 0.78 (0.69 to 0.87) and 0.85 (0.67 to 1.00) in the training and validation cohort, respectively. Earlier delivery and high rate of NICU admission occurred with severe ITP and treatment failure. Limitations The study was limited by a relatively small sample size and the retrospective observational design, which imposed limitations on the assessment of treatment efficacy. Conclusions We identified clinical predictors of ITP severity and treatment resistance during pregnancy. A nomogram predicting first-line response was validated. These findings can facilitate clinical decision-making and counseling regarding this challenging pregnancy complication.