Rates of childbirth amongst women with myeloproliferative neoplasms

Pregnancies in patients with myeloproliferative neoplasms (MPN) are often associated with poorer outcomes, including an increased risk of pre-eclampsia, as well as maternal and fetal morbidity. However, there are limited data on childbearing and birthrates amongst patients with MPN compared with the general population.¹

Here, we summarize a retrospective analysis by Landtblom et al.¹ published in Leukemia on the childbirth rates in women with MPN.

Study design¹

• Women with an MPN diagnosis, aged between 15 and 44 years, were selected from healthcare registers in Sweden.
• Patients were age-matched in a ratio of 1:4 with controls from the general population.
• The main outcome was time to first live childbirth post-MPN diagnosis.
  • Subgroup analyses were performed by age and MPN subtype.
• Secondary outcomes were miscarriage rate, and stillbirth pre- and post-MPN diagnosis.

Key findings¹

• A total of 1,141 patients with MPN and 4,564 control participants were included in this study.
• A 22% decreased childbirth rate was observed amongst the patients with MPN, compared with the control cohort (Figure 1).
  • Essential thrombocythemia was the only subtype with similar childbirth rates to the control group.
  • Childbirth rates were significantly reduced in all other MPN subtypes.
  • Women aged 15–25 years were observed to have significantly reduced birthrates compared with the control group.
  • No significant differences in birthrates were observed in any other age category.
• At the time of diagnosis, 61% of women with MPN had given birth to at least one child, compared with 67.3% in the age-matched controls (p < 0.001).
• With mean follow-up of 5 years, the risk of miscarriage was not significantly increased amongst patients with MPN compared with the control group; hazard ratio 1.25 (95% confidence interval [CI], 0.89–1.76).
  • However, women with MPN were more likely to have experienced a previous stillbirth, with fewer children in total.

Figure 1. Hazard ratio of live births per MPN subtype and age at diagnosis* 

CI, confidence interval; ET, essential thrombocythemia; MPN-U, myeloproliferative neoplasms-unclassified; PMF, primary myelofibrosis; PV, polycythemia vera.
*Data from Landtblom, et al.¹