Maternal cohort, time of stillbirth, and maternal age effects in Italian stillbirth mortality.

The cohort trend suggests that long term improvements in socioeconomic and general health conditions may be important factors in the diminishing stillbirth rates, as well as short term advances in obstetric care. Alternatively the cohort effect could be attributed, at least in part, to an age-period interaction, since the downward trends were more pronounced in younger women.