Purpose: To investigate whether an association exists between preterm delivery and a future risk for female malignancies.
Methods: A population-based study compared the incidence of long-term female malignancies in a cohort of women with and without a history of PTD. Deliveries occurred between the years 1988-2013, with a mean follow-up duration of 12 years. We excluded women with known genetic predisposition or malignancies prior to the index pregnancy. Malignancies investigated included ovarian, uterine, breast and cervix. Cumulative incidence was assessed using a Kaplan-Meier survival curve. A Cox proportional hazards model was used to estimate the adjusted hazard ratios (HR) for female malignancy.
Results: During the study period, 105,033 women met the inclusion criteria; 16.8 % (n = 17,596) of the patients delivered preterm. Patients with a history of PTD did not have an increased risk of later being diagnosed with female malignancies. The results remained insignificant in a sub-analysis based on malignancy type, early PTD, induced vs. spontaneous, and number of episodes per patient. Kaplan-Meier cumulative incidence was similar between the groups, and the adjusted HR was not significant (1.04, 95 % CI 0.88-1.22; p = 0.665).
Conclusion: A history of PTD does not appear to elevate the risk for subsequent long-term female malignancies.
Keywords: Breast cancer; Genital tract malignancies; Long-term risk; Maternal cancer; Preterm birth.