Impact and safety of pregnancy on desmoid fibromatosis management in the era of active surveillance. An international multicenter retrospective observational study

Abstract

Aim: To evaluate desmoid fibromatosis (DF) progression and obstetric outcomes during and after pregnancy, providing evidence to inform clinical decision-making and counseling.

Methods: This international, multicenter, retrospective observational study included data from 157 women with DF, contributing 177 pregnancies. Women were classified into three groups: DF diagnosed during pregnancy (Group A), pregnancy occurring after the diagnosis of DF (Group B: DF in situ during pregnancy), or pregnancy in previously resected DF (Group C). Logistic regression and tumor size trend analyses were conducted.

Results: Among 177 pregnancies, Group A exhibited the highest rates of DF progression (68.7 % during pregnancy, 40.6 % postpartum), while Groups B and C had lower progression rates (9.5 % during pregnancy, 8.3 % postpartum). Active treatment was required in 5.6 % of cases. Spontaneous regression occurred in 23.7 % of pregnancies, particularly following progression. Obstetric complications were comparable to those in the general population.

Conclusion: Pregnancy is generally safe for women with DF, particularly after prolonged disease stability. Individualized counseling is essential for managing risks of progression and recurrence, supporting informed fertility decisions. Referral to specialized centers is recommended to optimize DF management during family planning and pregnancy.

Keywords: Aggressive fibromatosis; Desmoid tumor; Desmoid-type fibromatosis; Pregnancy; Soft tissue sarcoma.