Cancer and pregnancy are likely increasing; however, updated estimates are needed to optimally address the unique needs of this patient population. The study aims to estimate the prevalence of cancer and cancer survivorship at delivery, to test the change in odds of cancer and cancer survivorship at delivery over the 10-year period, and to compare medical conditions, serious events, and obstetric complications between pregnancies with and without cancer at delivery.
 We conducted a retrospective analysis of the National Inpatient Sample (NIS), the largest all-payer inpatient health database in the United States. We identified delivery admissions from 2004 to 2013 with a concurrent diagnosis of cancer using International Classification of Disease, ninth revision (ICD-9) codes. Multivariable logistic regression was used to test the change in prevalence of concurrent cancer, cancer survivorship, and pregnancy and to compare outcomes between deliveries with and without cancer. All analyses were adjusted for NIS-provided population weights and strata.
 During the study period, the NIS represented a national estimate of 40,855,208 deliveries. The odds of cancer increased from 3.41/10,000 deliveries in 2004 to 4.33/10,000 in 2013. This trend was statistically significant, including after adjustment for maternal age (adjusted odds ratio [aOR] = 1.03 [95% confidence interval (CI): 1.01-1.04]). Cancer survivorship at delivery increased significantly (aOR = 1.07 [95% CI: 1.06-1.08]). Women with cancer more often experienced one or more of the following: death, ventilation, cardiac arrest, sepsis, or acute respiratory or renal failure during delivery (aOR for composite outcome 10.7 [95% CI: 6.6-17.2]), even after adjustment in a multivariable logistic regression model.
 The odds of cancer and cancer survivorship at delivery increased from 2004 to 2013, independent of maternal age. Women with cancer were more likely to experience medical or obstetric complications during their delivery compared with women without cancer. These findings highlight the importance of obstetric and oncologic clinical and research collaboration to improve patient care.
· The odds of cancer at delivery increased.. · Women with cancer may have delivery complications.. · Cancer survivorship at delivery increased..

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