Systemic Lupus Erythematosus Delivery Outcomes Are Unchanged Across Three Decades

Abstract

Objective: Using a large, de-identified electronic health record database with over 3.2 million patients, we aimed to identify trends of systemic lupus erythematosus (SLE) medication use during pregnancy and birth outcomes from 1989 to 2020.

Methods: Using a previously validated algorithm for SLE deliveries, we identified 255 pregnancies in patients with SLE and 604 pregnancies in controls with no known autoimmune diseases. We examined demographics, medications, SLE comorbidities, and maternal and fetal outcomes in SLE and control deliveries.

Results: Compared with control deliveries, SLE deliveries were more likely to be complicated by preterm delivery (odds ratio [OR]: 6.71; 95% confidence interval [CI]: 4.31-10.55; P < 0.001) and preeclampsia (OR: 3.22; 95% CI: 1.83-5.66; P < 0.001) after adjusting for age at delivery, race, and parity. In a longitudinal analysis, medication use during SLE pregnancies remained relatively stable, with some increased use of hydroxychloroquine over time but no increase in aspirin use. For SLE deliveries, preterm delivery and preeclampsia rates remained stable.

Conclusion: We observed rates of preeclampsia and preterm delivery in SLE that were five times higher than the general population and higher compared with other prospective SLE cohorts. Furthermore, we did not observe improved outcomes over time with preeclampsia and preterm delivery. Despite increasing evidence for universal use of hydroxychloroquine and aspirin, we did not observe substantially higher use of these medications over time, particularly for aspirin. Our results demonstrate the continued need to prioritize educational and implementation efforts to improve adverse pregnancy outcomes in SLE.

Figure 1

Flowchart of patient selection. (A) SLE pregnancies were selected from the EHR using four or more SLE ICD‐9 (710.0) or ICD‐10‐CM (M32.1 or M32.8 or M32.9) codes while also requiring one or more ICD‐9 or ICD‐10‐CM pregnancy or delivery‐related codes. A full list of these codes is in Supplemental Table 1. We then required chart review to confirm SLE diagnosis by a rheumatologist resulting in 174 SLE cases with 255 pregnancies and 132 SLE cases with 178 pregnancies with restricting to deliveries after SLE diagnosis. (B) Control pregnancies were selected from the EHR using the same pregnancy or delivery‐related codes used for the SLE pregnancies aforementioned along with requiring that controls not have codes for autoimmune diseases. We then chart‐reviewed a random 250 controls to ensure no autoimmune disease and to assess pregnancy outcomes, resulting in 224 mothers with 604 pregnancies. EHR, electronic health record; ICD, International Classification of Diseases; SLE, systemic lupus erythematosus.

Figure 2

Trends of medication use during SLE pregnancies. The x‐axis shows year SLE pregnancy occurred. The y‐axis shows the proportion of pregnancies with medication use in that particular year. Only SLE pregnancies that occurred after SLE diagnosis were included. For corticosteroids (red line with the stars), we see a relatively steady rate over time. For antimalarials (green line with diamonds), we see an increase in time, with a peak rate of about 70%. For aspirin (purple line with squares), we see a decline in use over time. For azathioprine (blue line with circles), we see low use and a relatively steady rate over time. SLE, systemic lupus erythematosus.

Figure 3

Trends of SLE and control pregnancy outcomes. (A) The x‐axis shows year pregnancy occurred. The y‐axis shows the proportion of pregnancies with the outcome in that particular year. Only SLE pregnancies that occurred after SLE diagnosis were included. Trends of SLE pregnancy outcomes were relatively stable over time, including live birth (red line with stars) and preeclampsia (green line with diamonds). Preterm delivery (blue line with circles) and cesarean section (purple line with squares) increased and then decreased. (B) Trends of control pregnancy outcomes were relatively stable over time. Compared with SLE pregnancies, control pregnancies had lower rates of cesarean section, preterm delivery, and preeclampsia. SLE, systemic lupus erythematosus.