TRENDS IN CESAREAN-SECTION RATES AMONG HIGH-RISK AND MEDIUM-RISK PREGNANCIES IN THE NETHERLANDS 1983-1992

During the last two decades, the rates of operative deliveries have be en rising constantly in all industrialized countries including the Net herlands, Within the framework of the project 'Obstetric Peer Review' (Verloskundige Onderlinge Kwaliteitsspiegeling), the trends in the cae sarean section rates were investigated, using the data of the Perinata l Database of the Netherlands (LVR), but only among the high- and medi um-risk pregnancies. To that end homogeneous high-risk subgroups, with respect to pregnancy-or delivery-related complications, were defined in various ways and caesarean section rates were calculated for these groups. Irrespective of the definition of such a group (e.g. multiple pregnancy or breech presentation), an increase of the caesarean sectio n rates evidently emerges. The rates of planned caesarean section appe ar to increase more than the rates of emergency caesarean section, The increase for the multiparae is greater than for the primiparae. It is striking that the largest increase was found within the medium-risk g roup (namely: singletons, at term, vertex presentation, normal birthwe ight, mothers aged 20-35 years and with a normal diastolic blood press ure). Although no evident pathology can be found in the data, these wo men do not belong to the low-risk group, because they were referred to an obstetrician. For the multiparae in this group, the risk of a plan ned caesarean section yearly increased by a factor 1.09 (i.e. 9%).