To study fetal outcome in women with primary Sjögren's syndrome (SS) compared to that in women with systemic lupus erythematosus (SLE) and healthy women, and to study the possible association of fetal loss with anticardiolipin antibodies (aCL) and antibodies to SS-A/Ro and SS-B/La in women with primary SS.
A retrospective analysis of the fetal outcome in 55 pregnancies in 21 patients with primary SS compared to that in 100 pregnancies in 42 patients with SLE and 94 pregnancies in 42 healthy women matched for age, parity and the onset of the autoimmune disease with respect to pregnancy. IgG-, IgM- and IgA-aCL were determined by a cofactor-dependent ELISA and antibodies to SS-A/Ro and SS-B/La by ELISA using human recombinant antigens and affinity-purified antigens.
Of all the 55 pregnancies in patients with primary SS, 8 (15%) occurred after the onset of primary SS symptoms. Eleven (20%) of the 55 pregnancies ended in fetal loss. The relative risk (RR) for fetal loss in patients with primary SS was 2.7 (95% CI 1.1-6.5; p = 0.023), and after the exclusion of the patient with four spontaneous abortions it was 2.0 (0.7-5.3; p = 0.18). In SLE the level of risk was 2.2 (0.9-5.0; p = 0.065). Fetal loss in patients with primary SS was not associated with elevated levels of anticardiolipin antibodies (aCL) or autoantibodies to SS-A/Ro or SS-B/La. Newborns of mothers with primary SS were not more premature or growth retarded than newborns of healthy women, but the absolute and the relative birth weights of the newborns of mothers with SLE was significantly lower than in healthy controls (P < 0.001 and P < 0.0001, respectively).
We conclude that the majority of pregnancies in women with primary SS occur before the onset of the disease and that these women have an increased risk of fetal loss, which is not associated with elevated levels of ACL or antibodies to SS-A/Ro or SS-B/La. The risk of fetal loss in primary SS is similar to that in women with SLE, but fetal growth retardation appears to be more common in SLE than in primary SS.