Analysis of outcomes in hospitalized pregnant patients with acute myeloid leukemia

There have been significant advances in the management of acute myeloid leukemia (AML) in the past decade. However, management of AML in the pregnant patient has been challenging as most interventions are contraindicated in pregnancy. Medical termination of pregnancy is advocated over chemotherapy in the first trimester as delaying chemotherapy could often be fatal. Chemotherapy during second and third trimesters may be provided with close surveillance of fetal abnormalities. The outcomes in these patients have not been systematically studied and have been limited to case reports and case series in medical literature.

Patients hospitalized with a diagnosis of AML were identified using the International Classification of Disease (ICD-9) codes in the National Inpatient Sample database. This database is maintained by the Agency of Healthcare Research Quality under the United States Department of Health and Human Services. It represents 20% of all hospitalizations occurring in the United States every year. Amongst these AML patients, all patients who were pregnant were identified and their demographic information was extracted. Other details related to their hospitalization, hospital size, location, region and teaching status were also determined. The association of outcomes with common medical comorbidities was studied. Pregnancy related outcomes, mode of delivery and mortality rates were calculated for the 15 year time period.

During the time period of 2000 to 2014, 678942 hospitalizations involved AML patients of which 5076 were noted to be from pregnant women. The hospitalization trend gradually increased over these years and was noted to be the highest in the age group of 18-34 years. The highest hospitalization rates were noted in African American and Native American patient populations. Hypertension, hyperlipidemia, chronic kidney disease and smoking were noted to be more prevalent in pregnant women with AML. A majority of these patients had a Charlson's comorbidity index of 1-3. 3.5% of patients underwent medical termination of pregnancy, 16.25% suffered from pregnancy related complications, 0.6% suffered from puerperal infection, 4% of patients had normal vaginal delivery, 2.8% of patients had caesarian section and 5.7% of patient died. The rate of mortality was the highest in Native Americans followed by Caucasians. Multiple regression showed that odds of mortality have decreased from 2000 to 2015 and that a higher Charlson's comorbidity score was an independent predictor of mortality.

This is the first nationwide study to document the outcomes of pregnancy in hospitalized AML patients. AML in pregnancy is rare and this study shows that the mortality has been improving over the past 15 years. Notably, vaginal delivery has been more common than caesarian section in pregnant AML patients. Native Americans have high prevalence and high mortality rates, a likely result of healthcare disparity. Pregnant AML patients with high Charlson's comorbidity score may benefit from aggressive management of their comorbidities. Further studies are required to better characterize outcomes in pregnant women with AML.