Fetal and Maternal Morbidity in Pregnant Patients with Thrombotic Thrombocytopenic Purpura: A Nationwide Analysis

Introduction: Thrombotic thrombocytopenic purpura (TTP) has been previously described in pregnancy, however there is limited data available on the impact of TTP in this subset of patients. In this analysis, we evaluate the maternal and fetal morbidity outcomes of TTP in hospitalized pregnant patients.

Methods: We used retrospective data from the National Inpatient Sample (NIS) to identify all hospital admissions of pregnant patients with and without TTP from 2012 to 2021 using ICD-9/10 codes. To describe the impact of TTP on maternal and fetal morbidity, we identified different morbidity indicators using standard Centers for Disease Control and Prevention (CDC) definitions with a particular focus on preeclampsia/eclampsia, thromboembolic events (venous and arterial), other organ failure, maternal morbidity and fetal outcomes including intrauterine growth restriction (IUGR) and fetal loss. To account for the effects of acute TTP during pregnancy versus a history of TTP, we separately analyzed hospitalizations that included plasma therapeutic plasma exchange (TPE). Predictors of maternal/fetal morbidities in pregnant TTP patients were determined using multivariable logistic regression analysis.

Results: We identified 7,514,304 pregnancy hospitalizations with a mean age of 29 years. Of these, 234 women had a diagnosis of TTP, with 74 receiving TPE during admission (acute TTP during pregnancy). Compared to pregnancy-related hospitalizations in women without TTP, those with TTP were more likely to be African American, admitted to urban teaching hospitals, have lower income, and have a higher Charlson Comorbidity Index (CCI). Most maternal morbidity outcomes were significantly higher in hospitalizations with TTP as compared to those without TTP including increased eclampsia (2.1% vs 0.08%), acute myocardial infarction (1.7% vs 0.01%, p<0.001), puerperal cerebrovascular disorders (8.1% vs 0.7%, p<0.001), cardiac arrest (0.9% vs 0.01%), acute renal failure (35% vs 0.2%, p<0.001), adult respiratory distress syndrome (ARDS) (6.4% vs 0.06%, p<0.001), disseminated intravascular coagulation (DIC) (18% vs 0.2%, p<0.001), pulmonary edema/acute heart failure (5.1% vs 0.1%, p<0.001), sepsis (9% vs 0.22%, p<0.001), shock (6.4% vs 0.1%, p<0.001), air/thrombotic embolism (3.0% vs 0.05%, p<0.001), blood transfusion requirement (25.6 vs 1.28%, p<0.001), and ventilation requirement (6.4% vs 0.06%, p<0.001). There was also a higher need for cesarean sections in TTP hospitalizations compared to non-TTP (57.1% vs 36.9%). For fetal morbidity outcomes, intrauterine growth restriction (IUGR) was more common in TTP hospitalizations (6.8% vs 2.4%, p<0.001), while there was no statistical difference between the two groups in the rates of preterm delivery (3.9% vs 3.3%, p=0.651). In-hospital mortality (1.7% vs 0.02%, p<0.001), and length of stay (11 vs 3 days, p<0.001) were also significantly higher in hospitalizations with TTP. Patients with TTP who received TPE during the hospital stay had worse maternal morbidity outcomes than those who did not, likely reflecting the active nature of the disease in this cohort. In the multivariate analysis, CCI ≥ 1 (OR 3.52, 95% CI, 1.64-7.54) and receipt of TPE (OR 2.99, 95% CI, 1.52-5.86) were associated with higher likelihood of maternal/fetal morbidity in TTP hospitalizations.

Conclusion: In conclusion, TTP has a significant impact on hospitalized pregnant patients, both on maternal and fetal outcomes. Further studies are needed to assess risk factors associated with TTP in pregnancy and ideal treatment regimens for these patients.