17
Statement 24
➤ In some institutions, women with a decreased ADAMTS13 activity
(e.g., <10 IU/dL) prior to or at the onset of pregnancy are offered
elective rituximab therapy, with the goal to eliminate ADAMTS13
autoantibodies and normalize ADAMTS13 activity before conception.
Evidence of increasing ADAMTS13 activity may be sufficient to
consider a lower risk of relapse in women with TTP.
Statement 25
➤ Patients treated with rituximab are usually asked to wait for 6-12
months following rituximab administration before trying to conceive;
normalization of CD19 lymphocyte levels and undetectable serum
rituximab levels are often used as evidence of "drug washout."
Global drug safety databases suggest that rituximab is associated
with few congenital malformations or neonatal infections, and the
scant case reports of its use in patients with TTP did not report
maternal or neonatal toxicity. However, women should be clearly
informed that the evidence about the safety and efficacy of rituximab
in pregnancy is extremely limited and inconclusive.
Statement 26
➤ Pregnant women with a history of either cTTP or iTTP are usually
closely monitored by a hematologist and an obstetrician with
experience in maternal fetal medicine/perinatology. The panel
supports the involvement of clinicians with expertise in TTP in the
care of pregnant women with a history of TTP. Complete blood counts
are usually monitored at least monthly. Plasma ADAMTS13 activity
is usually monitored monthly or every two to three months at least.
(More frequent monitoring tends to occur if the ADAMTS13 activity
begins to drop.)
Statement 27
➤ TTP presenting in pregnancy generally merits transfer to a specialist
center with hematologist, obstetrician, and transfusion medicine
specialists, and TPE capabilities, for comprehensive, definitive care.
As in suspected iTTP in non-pregnant patients, daily TPE is generally
initiated as soon as possible with fresh frozen plasma, cryopoor
plasma, or solvent detergent treated plasma as the replacement fluid.
The volume of replacement fluid is usually 1-1.5X plasma volume (i.e.,
40-60 ml/kg) every 24 hours.
