79The mean F.D.P. concentration of the women taking oral contraceptives, 15-78 ± 9-92 Lg/ml, was higher than that of any other group, but this figure was influenced by two values of 37-6 and 45-1 jig/ml, which were much higher than in any other women in the survey. There is no statistically significant difference between any of the groups shown in Table II; and the correlation coefficient (r = 0 02) between menstrual blood loss and serum F.D.P. is also not significant.
DiscussionUsing the tanned red cell haemagglutination inhibition immunoassay, Basu (1970) showed a significant rise in serum F.D.P. in all stages of the menstrual cycle in women complaining of menorrhagia, compared with a control group. Moreover, in both normal and abnormal groups there was a peak in serum F.D.P. concentration coinciding with menstruation. Basu (1970) concluded that these systemic manifestations of increased invivo fibrinolysis were evidence of intensive local intrauterine activity. However, Das et al. (1967) Rybo (1966) showed that increased intrauterine fibrinolysis, as measured by high levels of endometrial plasminogen activator, is associated with the actual volume of menstrual blood lost rather than with the complaint of menorrhagia.MAinor, but important, differences in the F.D.P. assay technique between Basu's (1970) laboratory and our own may also be relevant; in particular, the specificity of the antisera used, with special reference to the relative sensitivity of tests to detect the antigenically dissimilar D and E fragments. Checking our own antiserum with purified D and E products has shown extreme sensitivity to fragment D and only slightly less sensitivity to E.Consideration of previous studies in which serum F.D.P. estimations have often failed to show evidence of intense localized fibrin deposition and fibrinolysis, as in the case of renal homotransplantation (Colman et al., 1969;Clarkson et al., 1970) and of proliferative glomerulonephritis (Clarkson et al., 1971), makes the absence of a significant rise in serum F.D.P. in women with heavy menstrual blood loss, as reported in this paper, not unexpected. Thus, from a practical point of view, at the present time we have no reason to believe that isolated or serial measurements of serum F.D.P. in women complaining of menorrhagia will assist the gynaecologist in selecting those patients who might benefit from oral antifibrinolytic agents (Nilsson and Rybo, 1971 (1965). Acta Medica Scandinavica, 177, 445. Nilsson, L., and Rybo, G. (1971). American Journal of Obstetrics and Gynecology, 110, 713. Rybo, G. (1966