[Influence of parity and legitimacy on late fetal mortality in Castilla-León].

: Biological and social factors affecting of late fetal death (LFD), made up by those dead births of twenty eight or more weeks gestation, are studied. Influence of parity (birth order) and civil status of mother (single, married) are analysed in Castilla-Leon during 1975-1979 through Logit models. Between the hierarchical non permeated models, considered before, it was choose the one made out of (parity X status) (year). If we make a detailed fitting, civil status as main effect is eliminated, obtaining a new model: (parity) (year) (parity X status). A constant tendency to decrease LFD during the studied years is observed. It is pointing out the importance of the whole study, about parity and civil status, as an explanatory factor of this mortality.