Decrease in Pregnancy Loss Rates in Patients with Systemic Lupus Erythematosus over a 40-year Period

Objective: To determine if there has been a statistically significant change in pregnancy loss and preterm delivery rates in patients with systemic lupus erythematosus (SLE).

Methods: We analyzed the pregnancy outcomes of our SLE patients over the past 3 years and reviewed the literature over the past 40 years. We extracted pregnancy loss and preterm delivery data from reports of postdiagnosis SLE pregnancies. Studies were grouped into 5-year periods and weighted according to sample size. Group means, calculated for each study period, were plotted using linear regression to determine significance, and compared with population norms for the same periods.

Results: The rate of loss in SLE pregnancies over the past 40 years decreased from a mean of 43% in 1960-1965 to 17% in 2000-2003 (r2 = 0.648). This approximates the pregnancy loss rate in the general US population. Preterm deliveries were not uniformly reported and were rarely stratified into spontaneous or physician-initiated. Prior to 1980, it was not possible to derive group means for each time period. From 1980 to 2002, however, there was a trend toward a decrease in preterm births in SLE pregnancies, although they continue to be more frequent in SLE than in the general population.

Conclusion: Improvements in disease management and perinatal monitoring have resulted in a significant decrease in pregnancy loss in SLE over the last 40 years and a trend toward decreased preterm deliveries over the last 20 years in comparison to the general population. These advances highlight the importance of collaboration between rheumatologists and perinatologists. Given these data, the description of SLE-associated pregnancy could be revised to reflect a more positive prognosis for mother and fetus.