Intravenous immunoglobulin (IVIG) use in pregnancy, particularly for fetal and neonatal alloimmune thrombocytopenia (FNAIT), is increasing and needs better guidance to balance patient benefit with limited supply, according to a study published recently in Hematology, Transfusion and Cell Therapy.
Researchers found that while IVIG can be lifesaving in FNAIT, much of its obstetrical use occurs outside federally licensed indications, raising questions about evidence, cost and long-term sustainability for patients who depend on this therapy.
This single-center retrospective study reviewed IVIG use in 136 pregnancies among 122 patients treated at the Ottawa Hospital from 2007 to 2020. During that period, pregnant patients received a cumulative 41,107.50 grams of IVIG, representing 1.6% of the hospital’s total IVIG consumption.
Although this proportion is small, obstetrical use increased over time, especially in later years. Annual mean IVIG use in pregnancy was 2,936.25 grams, compared with 183,983.32 grams for the overall hospital population.
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“These findings underscore the need for stewardship programs to optimize IVIG use in pregnancy, ensuring that this valuable resource is used effectively and responsibly in clinical practice,” explained this study’s authors.
Conditions affecting blood and platelets dominated IVIG use. Maternal thrombocytopenia occurred in 56.6% of deliveries, while antenatal treatment for FNAIT occurred in 16.2%. Despite fewer cases, FNAIT accounted for most of the IVIG volume used in pregnancy, totaling 26,435 grams or 64.3% of all obstetrical IVIG. These pregnancies often required weekly infusions throughout the second and third trimesters, explaining spikes in annual use. By comparison, maternal thrombocytopenia accounted for 6,952.50 grams or 16.9% of total volume.
For families affected by FNAIT, IVIG is widely considered the treatment of choice, even though strong clinical trial evidence is limited. Small observational studies suggest benefit, and expert consensus has driven its routine use to protect the fetus and newborn.
This study also found that 38.2% of pregnancies received IVIG for indications not licensed by Health Canada. These off-label uses, including FNAIT, accounted for 80.3% of total IVIG volume used in pregnancy. In contrast, only 17.6% of pregnancies did not meet Ontario’s provincial utilization guidelines, highlighting differences between regulatory approval and real-world clinical practice.
For patients, these results underscore why IVIG access matters. IVIG is costly and in limited supply, yet it may prevent devastating outcomes in conditions such as FNAIT. The authors emphasize the need for more research to confirm who benefits most, refine dosing strategies and ensure IVIG remains available for pregnant patients and babies who truly need it.
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