[Methodologic aspects and results of a complex long term analysis of a perinatal/peripartal care system. 3. Dynamic aspects].

One important premise for estimation of the development of the results of defined care systems is the observation of movements in time. Besides the knowledge of internal systemic changes also the influence of external factors has to be considered, especially volume and structure of the clientel. Simple methodic statements are sufficient analysing the development complexly.--The secular dynamic of the care system has been objected by uniform use of a defined trend-ratio. The influences after the second world war and some actual trends are reported besides the longtime trend explicitly. Finally a workinghypothesis is formulated in regard to the reasons of preterm labour and fetal retardation.