Objective: To determine the frequency of pregnancy loss, preterm birth, and therapeutic abortion in patients with systemic lupus erythematosus (SLE) versus controls.
Method: The outcome of lupus pregnancy was determined in the largest retrospective case-control study to date, involving 203 patients with SLE with 481 pregnancies, 166 "best friends" with 356 pregnancies and 177 relatives with 566 pregnancies.
Results: Pregnancy loss (spontaneous abortion, miscarriage, or stillbirth) was more common in lupus pregnancies (21%) than in pregnancies in friends (14%, p = 0.01) or in relatives (8%, p < or = 0.0001) and was more common after the diagnosis of SLE than before (27 19%, p = 0.04). Preterm birth (< or = 36 weeks) was more common in lupus pregnancies (12%) than in pregnancies in friends (4%, p < or = 0.0001) or in relatives (4%, p < or = 0.0001) and was more common after the diagnosis of SLE than before (24 vs 6%, p < or = 0.0001). Preterm birth in lupus pregnancies after the diagnosis of SLE was associated with nonhigh school graduates (p = 0.001), Raynaud's phenomenon (p = 0.007), and hypertension requiring treatment (p = 0.01).
Conclusion: We conclude that both pregnancy loss and preterm birth are significantly increased in lupus pregnancy versus control pregnancy and that these pregnancy outcomes are more common after the diagnosis of SLE.