Maternal morbidity and mortality among patients with cancer at time of delivery

Individuals with cancer during pregnancy are a medically complex patient population that is anticipated to grow. A better understanding of this population and patterns of risk at time of delivery would offer an opportunity for providers to mitigate maternal morbidity.

This study aimed to estimate the prevalence in the United States of concurrent cancer diagnoses at time of delivery by cancer type and associated maternal morbidity and mortality.

Using the National Inpatient Sample, we identified delivery-associated hospitalizations between 2007 and 2018. Concurrent cancer diagnoses were classified using the Clinical Classifications Software. Main outcomes included severe maternal morbidity, as defined by the Centers for Disease Control and Prevention indicators, and mortality during delivery hospitalization. We calculated adjusted rates for cancer diagnosis at time of delivery and adjusted odds ratios of severe maternal morbidity and maternal death during hospitalization using survey-weighted multivariable logistic regression models.

In this sample of 9,418,761 delivery-associated hospitalizations, 63 per 100,000 deliveries had a concurrent cancer diagnosis (95% confidence interval, 60-66; national weighted estimate, 46,654,042). The most common cancer types were breast cancer (8.4 per 100,000 deliveries), leukemia (8.4 per 100,000 deliveries), Hodgkin lymphoma (7.4 per 100,000 deliveries), non-Hodgkin lymphoma (5.4 per 100,000 deliveries), and thyroid cancer (4.0 per 100,000 deliveries). Patients with cancer were at significantly higher risk for any severe maternal morbidity (adjusted odds ratio, 5.25; 95% confidence interval, 4.73-5.83) and maternal death (adjusted odds ratio, 67.5; 95% confidence interval, 45.1-101.4). Risks of hysterectomy (adjusted odds ratio, 16.92; 95% confidence interval, 13.96-20.52), acute respiratory distress (adjusted odds ratio, 12.76; 95% confidence interval, 9.92-16.42), sepsis (adjusted odds ratio, 11.91; 95% confidence interval, 8.68-16.32), and embolism (adjusted odds ratio, 11.12; 95% confidence interval, 6.94-17.82) were particularly heightened among patients with cancer. Patients with leukemia, specifically, had the highest risk of adverse maternal outcomes (adjusted rate, 113 per 1000 deliveries; 95% confidence interval, 91-135 per 1000) when evaluating risk by cancer type.

Patients with cancer are at markedly increased risk of maternal morbidity and all-cause mortality during delivery-associated hospitalization. Risk is distributed unevenly within this population, with certain cancer types carrying unique risks for specific morbidity events.