Research reveals racial and ethnic disparities persist in pregnancy outcomes of patients with lupus

While investigators have known that maternal and fetal outcomes of pregnancy among women with systemic lupus erythematosus (SLE) have improved over time, it is unknown whether the improved outcomes are shared equally among different racial and ethnic groups. Lupus has been shown to disproportionately affect minorities of childbearing age. A new study that includes researchers from Hospital for Special Surgery (HSS) presented today at the American College of Rheumatology (ACR) annual meeting shows that pregnancy outcomes in women with lupus have improved in all racial and ethnic groups over the past decade, but disparities still exist.

"We're happy to see pregnancy outcomes improved over time in all of the groups studied, however improvements were more evident in some groups than others," said lead study author Bella Mehta, MBBS, MS, MD, a rheumatologist at HSS. "African Americans and Hispanics continue to have poor pregnancy outcomes. Further study is warranted to determine where resources are needed to improve access and care for these patients."

In the new study, researchers used the National Inpatient Sample (NIS) to conduct a retrospective cross-sectional analysis of lupus and pregnancy related hospital admissions from 2008 to 2017. The NIS is the largest publicly available all-payer healthcare database designed to produce US regional and national estimates of inpatient utilization, access, cost, quality and outcomes. Patients with lupus were identified by using ICD-9/10 codes. The researchers evaluated the pregnancy outcomes of four groups: Caucasians, African Americans, Hispanics and Asians/Native Americans/Others. Outcomes included in-hospital maternal mortality, fetal mortality, non-delivery related admissions and Cesarean section (C-section).

The investigators found that from 2008 to 2017, there were a total of 61,012 SLE pregnancy related hospitalizations. The median age of pregnant women in the sample was 29 for African American and Hispanic women, 30 for Caucasians, and 31 for Asians/Native Americans/Others. African Americans and Hispanics were more likely to be on Medicaid (51% and 49% respectively) versus Caucasians (30%) and Asians/Native Americans/Others (33%).

During the 10-year study period, fetal mortality and non-delivery related admissions and C-section rates improved in all racial/ethnic groups. Maternal mortality rates were very low throughout the study period, with none observed among Caucasians. Overall fetal mortality declined in all racial/ethnic groups, with a numerically greater reduction in Hispanic (from 291 in 2008-2009 to 101 in 2016-2017 per 10,000 admissions) and Asian/Native American/Other (from 267 in 2008-2009 to no observations in 2016-2017 per 10,000 admissions) versus Caucasian (from 136 in 2008-2009 to 108 in 2016-2017 per 10,000 admissions) and African American (from 385 in 2008-2009 to 308 in 2016-2017 per 10,000 admissions). In the latest data from 2017, African Americans continued to have worse fetal mortality than Hispanic or Caucasian patients, and Asians/Native Americans/Others had the least fetal mortality. In data from 2017, African Americans had the most non-delivery admissions, followed by Hispanics, Asians/Native Americans/Others and Caucasians. In 2017, C-section rates were highest in African Americans, followed by Caucasians, Asians/Native Americans/Others, and Hispanics.

"We have learned over the years that patients with lupus can become pregnant but need to do so in a certain way. That is, they should have quiet disease activity at conception and they shouldn't become pregnant if they have serious internal organ damage such as renal failure," said study co-author Lisa R. Sammaritano, MD, a rheumatologist at HSS. "What this study shows is there is still a persistent disparity between non-Caucasian ethnic groups and Caucasians in terms of pregnancy outcomes in women with lupus, but both groups have had improvement over 10 years.

"It's good to see that improvements have been across racial and ethnic groups, but we need to continue to work toward identifying the reasons disparities still exist," she continued. "This kind of large database study is very useful in looking at this type of problem across the country as a whole, rather than a study focused on a single hospital system, as most other studies do."