Participants and descriptive data
Of 531 129 screened parturients, 247 536 met the inclusion criteria
(Figure 1). The mothers showed a mean age of 28 years and a gestation
week of 39+6. An overview of the demographic data of all parturients are
listed in Table 1. Forty-one percent of deliveries took place in
hospitals with less than 500 deliveries per year.