Longitudinal Analysis Suggest Pregnancy Outcomes Unchanged in Patients With SLE

Outcomes for pregnant women with systemic lupus erythematosus (SLE) have remained relatively unchanged over the past 3 decades, according to a new study. The report also found that rates of hydroxychloroquine and aspirin use did not increase substantially over that time frame, even as evidence suggesting their benefits has mounted.

The study was published in ACR Open Rheumatology.

Patients with SLE have a higher risk of adverse pregnancy outcomes, including preterm delivery and preeclampsia. Yet, the authors said most existing research in this area has been based on prospective studies with relatively small sample sizes. Administrative databases can lend insights because of their larger sample sizes, but the authors said studies of these data sets rely on billing codes and do not have sufficient granular data to ensure that patients’ statuses are accurate.

Instead, the authors turned to electronic health records, which they said have the advantages of providing longitudinal data and full data on patient comorbidities. They used a de-identified copy of a Vanderbilt database with records of 3.2 million patients that stretched from 1989 to 2020.

The authors found 255 pregnancies in which the patient had an SLE diagnosis confirmed by a rheumatologist. Next, they pulled a control group of 604 pregnancies in which the patient had no known autoimmune diseases.

Overall, they found that deliveries by people with SLE had a significantly higher risk of both preterm delivery (odds ratio [OR], 6.71; 95% CI, 4.31-10.55; P < .001) and preeclampsia (OR, 3.22; 95% CI, 1.83-5.66; P < .001) compared with deliveries within the control group.

“As expected, there were worse outcomes in our SLE pregnancies compared with our controls, as has been previously reported,” the authors wrote.

They also looked at subgroups of patients based on whether their SLE diagnosis or their pregnancy came first. However, the outcomes of both groups were similar, with preterm delivery rates of 40% and 51% in patients with a pregnancy before and after their SLE diagnosis, respectively (P = .24), and preeclampsia rates of 19% and 25% (P = .42), respectively.

The authors then conducted a longitudinal analysis to identify trends in outcomes and medication use. However, they found little change. Hydroxychloroquine use increased modestly, aspirin use did not change significantly, and rates of preterm delivery and preeclampsia were stable. The authors noted that 2020 guidance from the American College of Rheumatology recommends hydroxychloroquine use by all pregnant patients with SLE, except in cases where it is contraindicated.

“While most of the SLE pregnancies in our cohort occurred before the 2020 guidelines, our results demonstrate the continued gaps of care, with a need to increase both hydroxychloroquine and aspirin use in SLE pregnancies,” the investigators wrote.

As for aspirin, the authors noted that the medication is available over the counter, so patients might have been using it even though the medication’s use was not reflected in the patient’s health records. However, the authors said they tried to overcome that problem by performing chart reviews of notes to identify patients who were taking aspirin even if it was not listed on their medication lists.

The authors said corticosteroid use was frequent among the SLE cohort. They noted that corticosteroid use and SLE nephritis have been linked with adverse pregnancy outcomes, but their data did not show a similar association.

They cautioned that their data only represent the results from a single center, and thus may not be generalizable. In addition, because their data come from a tertiary referral care center, it might be biased toward more severe cases.

Still, they concluded that the findings indicate there is still considerable work to be done to improve outcomes for patients with SLE who become pregnant.

“These results highlight persistent gaps in management strategies for SLE pregnancies and the continued need to direct resources to improve care in these high-risk patients,” they wrote.

Reference

Barnado A, Hubbard J, Green S, Camai A, Wheless L, Osmundson S. Systemic lupus erythematosus delivery outcomes are unchanged across three decades. ACR Open Rheumatol. Published online June 6, 2022. doi:10.1002/acr2.11447