The project "Obstetric Peer Review Interventions" (Verloskundige Onderlinge Kwaliteitsspiegeling Interventies, VOKSINT) was set-up in The Netherlands in 1994. It provided annual comparison data (quality ranking, league tables) for secondary care obstetric departments adjusted for population differences, based on the data registered in the Perinatal Database of The Netherlands (Landelijke Verloskunde Registratie, LVR). The aim of the so-called VOKS reports was to influence obstetricians' interventions in such a way that they led to a more homogeneous policy. To assess this influence, a trial was set-up, with departments randomly assigned to be or not to be informed about the VOKS results. Obstetric intervention rates and the morbidity of newborns including neonatal neurological examinations (NNEs) were assessed. Obstetric intervention rates were similar in the report group and the control group. Practice in the report group became more homogeneous (adjusted for population differences) than in the control departments, but this was only statistically significant for term caesarean section.