TTP in pregnancy boosts adverse maternal, fetal outcomes: Study
Being older then 35, coexisting medical conditions among risk factors
Written by |
Pregnant women with thrombotic thrombocytopenic purpura (TTP) in the U.S. are nearly 20 times more likely to experience an adverse maternal outcome, according to a nationwide study.
Likewise, there were twice as many adverse fetal outcomes, primarily an underdeveloped fetus, in pregnant women with TTP than in those without.
Overall, an age of 35 and older and the presence of coexisting medical conditions were associated with higher odds of severe maternal or fetal outcomes, the analysis showed.
“Pregnancy associated with TTP is associated with inferior maternal and fetal health outcomes,” researchers wrote in the study, “Fetal and maternal morbidity in pregnant patients with thrombotic thrombocytopenic purpura: A Nationwide analysis,” published in the journal Transfusion.
Pregnancy a well-established trigger of TTP
TTP is a rare, life-threatening blood disorder in which small blood clots form in the body’s blood vessels, leading to organ damage.
Women are disproportionately affected by TTP, accounting for over 70% of cases, with nearly half of those occurring during reproductive age. Pregnancy is a well-established trigger of TTP, which usually appears in the third trimester. As a result, diagnosing and treating TTP early is essential to prevent complications for both the mother and fetus.
“However, there is limited data on the impact of a TTP diagnosis on pregnancy outcomes,” wrote researchers in the U.S. who used data from the National Inpatient Sample database to describe the impact of TTP on maternal and fetal outcomes.
The team identified 7,397,411 hospitalizations of pregnant women, ages 18 and older, 234 (0.003%) of whom had a diagnosis of TTP and ranged in age from 18 to 47. Among those with TTP, 73 received therapeutic plasma exchange (TPE) during admission. In TTP, a patient’s own plasma (blood without cells) is replaced with healthy plasma.
Compared with women without TTP, those with TTP were more likely to have a lower income, be African American, receive treatment in urban teaching hospitals, and have a higher Charlson comorbidity index score, which is a measure of coexisting conditions. TTP patients were also more likely to have the autoimmune conditions lupus or antiphospholipid syndrome.
Adverse outcomes 20 times more likely in women with TTP
In total, there were 451,381 (6.1%) hospitalizations with at least one severe adverse maternal (morbidity) outcome, totaling 500,204 events.
When compared, the rates of such adverse outcomes were nearly 20 times more likely in women with TTP than in those without TTP — 133 vs. 6.75 events per 100 admissions.
Adverse events included heart attacks, heart failure, kidney failure, acute respiratory distress syndrome, fluid in the lungs (pulmonary edema), sepsis (an extreme reaction to an infection), blood transfusion, and the use of mechanical ventilation to help breathe.
Adverse fetal outcome rates were double in women with TTP compared with those without TTP — 11 vs. 5.64 per 100 admissions. An underdeveloped fetus was significantly more common in TTP pregnancies (6.9% vs. 2.3%), but there was no difference in the rates of preterm deliveries.
Other adverse outcomes that occurred significantly more often in TTP women included in-hospital mortality (1.7% vs. 0.01%), cesarean deliveries (51.5% vs. 32%), preeclampsia (37.3% vs. 5.1%), and longer length of hospital stay (10.9 vs. 2.6 days). Preeclampsia is a condition marked by high blood pressure.
Pregnancy associated with TTP, whether active requiring treatment or not, is associated with detrimental maternal and fetal health outcomes.
TTP patients who received TPE, which was treated as a surrogate marker of active TTP, had significantly higher rates of acute kidney failure, blood transfusions, and disseminated intravascular coagulation, in which blood clots form throughout the body, impairing blood flow.
Those who received TPE were also associated with higher odds of severe maternal or fetal outcomes, likely reflecting the subset of patients with true active TTP, versus a history of TTP, during the hospitalization, the team noted.
In an adjusted statistical analysis, an age of 35 and older and a Charlson comorbidity index of at least 1 were associated with higher odds of severe maternal or fetal outcomes.
“Pregnancy associated with TTP, whether active requiring treatment or not, is associated with detrimental maternal and fetal health outcomes,” the researchers concluded.
