title: Methodological problems in the studies of reproductive failures.
abstract: Epidemiological studies of reproductive failures are still rather few in spite of the importance of the research. One of several reasons for this could be the methodological problems of such studies. Some of these problems are discussed in this communication.
authors.affiliation: Institute of Social Medicine, Aarhus, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Olsen
mesh_terms: D000028:Abortion, Induced; D004812:Epidemiologic Methods; D005260:Female; D005298:Fertility; D005315:Fetal Diseases / Q000453:epidemiology / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D015233:Models, Statistical; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D011256:Pregnancy Outcome; D012107:Research Design; D012307:Risk Factors