Navigating myeloproliferative neoplasms during pregnancy: from preconception to postpartum

Thita Chiasakul; Ross I. Baker

doi:10.69898/jhtm.35.2025.279920

The classical Philadelphia chromosome-negative myeloproliferative neoplasm (MPN) is a heterogeneous group of clonal hematopoietic stem cell disorders that include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). These disorders are characterized by one of the shared driver mutations, JAK2, calreticulin (CALR), and MPL, which result in consecutive activation of the JAK-STAT signaling pathway, eventually leading to abnormal hematopoietic cell proliferation and excessive cytokine production. Although MPNs have traditionally been considered diseases of older adults–given a median age at diagnosis in the 60s–their occurrence in adolescents and young adults is increasingly recognized, with 10-20% of cases diagnosed before the age of 40.3 Among this younger population, ET is the most common subtype and displays a female predominance (65-70%), highlighting the clinical importance of reproductive health and pregnancy considerations. Additionally, the trend toward advanced maternal age further contributes to the growing number of pregnant patients with MPN. Pregnancy in women with MPN poses unique challenges (Figure 1). Thrombosis and bleeding are common complications that contribute to significant morbidity and mortality in MPNs. Consequently, the prevention of thrombotic events is considered one of the primary goals in the management of MPN and therapeutic options are considered based on an individual’s thrombotic and bleeding risk profile. Pregnancy by itself is a pro-thrombotic state, driven by estrogen-mediated changes in coagulation and fibrinolysis. The risk of venous thromboembolism (VTE) is increased approximately 4-to 5-fold during pregnancy, and up to 20-fold in the postpartum period, compared to nonpregnant women. When compounded by MPN, this baseline risk escalates further, presenting considerable challenges to fetal and maternal outcomes. In women of childbearing age presenting with unusual thrombotic events–particularly in atypical sites such as the splanchnic or cerebral veins–a complete blood count (CBC) should be reviewed closely for features suggestive of an underlying MPN, including erythrocytosis, leukocytosis, or thrombocytosis. Importantly, initial clinical presentation leading to a diagnosis of a MPN in women of reproductive age may differ substantially from the classic presentations seen in older populations. In some cases, diagnosis may follow a venous or arterial thrombotic event, while in others it may be triggered by recurrent pregnancy loss, abnormal uterine bleeding, or other atypical bleeding symptoms. In many women, the diagnosis may even arise incidentally through routine blood work. These diverse presentations are not well captured in current studies but are clinically important, as each scenario may require a tailored diagnostic and management approach, particularly in the context of pregnancy or fertility planning...

Navigating myeloproliferative neoplasms during pregnancy: from preconception to postpartum

Files and links (1)

Abstract

Details

UN Sustainable Development Goals (SDGs)

Metrics