title: On the role of 'habitual aborters' in the analysis of spontaneous abortion.
abstract: Analyses of spontaneous abortion rates often include special provisions to account for the presumed distorting effects that arise because of the presence of habitual aborters. In this paper, I establish a framework for investigating the effects of the presence in study groups of such women. I then examine the strengths and weaknesses of some of the analysis strategies in current use, both in situations where the study group is homogeneous and where there are high-risk women present. I show that the concept of habitual aborter is not useful and can be misleading, and I suggest that one take a broader view of heterogeneity.
mesh_terms: D000026:Abortion, Habitual / Q000453:epidemiology*; D000022:Abortion, Spontaneous / Q000453:epidemiology*; D001699:Biometry; D005260:Female; D006801:Humans; D008962:Models, Theoretical; D011247:Pregnancy; D012306:Risk