Analysis of perinatal mortality rate in the Stockholm area.

During the period 1973--1976, a significant decrease in perinatal mortality from 14.2 to 10.4/10 newborns occurred in Sweden. In the Stockholm area, the mean perinatal mortality during the same period varied significantly between the different maternity hospitals, even when pre-term and high risk pregnancies were excluded from the comparison. The majority of hospitals with fewer deliveries and without pediatric wards had a perinatal mortality above the mean. Some explanations of these differences were also looked for in differences between the total population of the referral area of each maternity hospital. In the referral areas of the hospitals with a perinatal mortality above the mean, there were higher percentages of low-income households and over-crowded dwellings and fewer professional people than in the other area. The results suggest a need for analysis of individually-based data to find etiological factors which account for differences in perinatal mortality.