LUPUS ANTICOAGULANT AND REPEATED ABORTIONS: A CASE- CONTROL STUDY

In the last few years a role of Lupus Anticoagulant (LAC) in the aetiology of repeated spontaneous abortions and intrauterine deaths has been repeatedly suggested. To quantify this association few da ta are available, since the published reports are generally based on uncontrolled and small clinical series. We have analyzed data from a case-control study conducted in Bergamo and Milan, two contiguous provinces in Lombardia, Italy. Cases were 63 women, mean age 30 years, range 23-40, with 2 or more "sine causa" spontaneous abortions (repeated abortions) admitted between March 1985 and December 1986 to the Ospedali Riuniti of Bergamo and Istituti Clinici di Perfezionamento of Milan. Controls were 63 women, mean age 32 years, range 20-49, with 1 or more live births and without spon taneous abortions, admitted to the same Institutions for neither gynaecological nor cardiovascular acute conditions. Informations were collected on sociodemographic factors, gynaecological and obstetrical data and related medical history. LAC was diagnosed according to the Working Party reccomandations (1983) and Systemic Lupus Erythematosus (SLE) according to the revised criteria of ihe American Rheumatism Association (1982). 11 out of 63 cases (17%) (95% confidence interval ranging from 9.5% to 34% based on the Poisson's approximation) were LAC positive, whereas in none of 63 controls this inhibitor was detected (X2 1adjusted for age = 10.1, p= 0.02). Similarly SLE was diagnosed in 4 cases (all having a Lupus Anticoagulant) and in none control (x2 1adjusted for age= 4.17, p=0.02). These findings confirm that LAC is associated with a positive history of repeated abortions, being present in about 10% of the cases. Conclusive estimate of relative risk is prevented by the small control gr'oup size (i.e. lack of positivity for LAC in controls), but very elevated risk (many tenfold increase) is sugge. sted.