Obstetric complications at time of delivery amongst breast cancer survivors: A population-based cohort study

PURPOSE: Our aim was to determine whether breast cancer survivors are at increased risk of obstetric and maternal complications at time of delivery. METHODS: The USA ‘National Inpatient Sample’ database was queried for hospitalizations associated with deliveries, between 2015 and 2018. The incidence of maternal and fetal complications was compared between women with, and without, a personal history of breast cancer. RESULTS: Of the 2,103,216 birth related admissions, 617 (0.03%) of the women were breast cancer survivors, with the proportion increasing over time (from 0.02% in 2015 to 0.04% in 2018). Breast cancer survivors had a higher socioeconomic status (p < 0.001) and were significantly older compared to other mothers (34 vs. 28 years, p < 0.001). Additionally, they were more likely to suffer from preexisting chronic diseases including cardiopulmonary disease and diabetes mellitus, and had a higher incidence of multiple gestation (4.4% vs. 1.6%) [OR 2.7, 95% CI 1.9–4.0, p < 0.001]. The incidence of acute adverse events at time of delivery including fetal distress, preterm labor, cesarean section and maternal infection was higher amongst the breast cancer survivors. On multivariate analysis age, ethnic group, comorbidities, multiple gestations, and a previous breast cancer diagnosis, but not cancer treatment, were associated with an increased risk of an obstetric adverse event. CONCLUSION: Breast cancer survivors have more comorbidities and are at increased risk of acute obstetrical complications at time of delivery. Further studies are required to validate these findings, and evaluate the ability of interventions to improve obstetrical outcomes amongst breast cancer survivors.