Interferon therapy for pregnant patients with essential thrombocythemia in Japan

Essential thrombocythemia (ET) mainly affects the elderly, but can also develop in women of childbearing age. The risk of miscarriage and other complications during pregnancy in ET patients are reported to be higher than that compared to the general population. Therefore, management of pregnancy in ET patients requires special considerations. Several groups recommend interferon (IFN) therapy for ET patients with high-risk pregnancies, but currently no guidelines are available in Japan. We report the outcomes of nine ET patients with ten consecutive high-risk pregnancies. All patients were successfully managed with IFN-alpha during their pregnancies. All patients also received aspirin and switched to unfractionated heparin around 36 weeks of gestation. As for the seven pregnancies in which IFN-alpha was started after detection of pregnancy, median platelet counts decreased from 910 to 573 x 10(9)/L after 2 months of IFN-alpha therapy, and median platelet counts at the time of delivery for all ten pregnancies was 361 x 10(9)/L. All patients gave birth to healthy children. IFN-alpha was well tolerated, safe, and effective as a cytoreductive therapy for all patients. Although evidence is limited and the use of IFN is not approved in Japan, we suggest considering IFN therapy for high-risk ET pregnancies.

Automated summary

ET patients with high-risk pregnancies may benefit from interferon (IFN) therapy to reduce complications. Close monitoring and early intervention throughout pregnancy can help to manage risks effectively.