Impartial analyses of the evidence from official statistics, national surveys and specific studies consistently find that perinatal mortality is much higher when obstetric intranatal interventions are used, as in consultant hospitals, than when they are little used, as in unattached general practitioner maternity units and at home. The conclusion holds even after allowance has been made for the higher pre-delivery risk status of hospital births as a result of the booking and transfer policies. It holds even more strongly for births at high than at low predicted risk. It follows that the increased use of interventions, implied by increased hospitalization, could not have been the cause of the decline in the national perinatal mortality rate over the last 50 years and analysis of results by different methods confirms that the latter would have declined more in the absence of the former. Data are presented which point to the deleterious effect of interventions on the incidence of low birthweight and short gestation and their associated mortality. Also presented are data supporting the alternative explanation of the decline in perinatal mortality, namely the improvement in the health status of mothers built up over several generations. The organization of the maternity service stands indicted by the evidence. Despite the beliefs of those responsible, it has not promoted, and cannot promote, the objective of reducing perinatal mortality.