The AUDIPOG association (Association of Users of Computerized Files in Perinatalogy, Obstetrics and Gynaecology) proposed in 1994 the setting up of the Sentinel Network, including voluntary public and private maternity units from all areas in France. Each year, every member sends individual data related to a sample of births to the AUDIPOG Network. Today, the common database comprises 95,000 births collected during one month by all members of the network. Thanks to a standardization procedure, the perinatal health indicators, obtained from the common database, are valid estimations at the national level. The results of a given year are published at the beginning of the following year, providing a continual survey of perinatal indicators in France. Since the regionalization of perinatal services, a common perinatal information system is of great importance for a continual survey of perinatal health indicators and assessment of medical practices. Among the most important results of this perinatal network, we observed an increase in the rate of multiple pregnancies from 3.5% of births in 1998 to 4.2% in 2001. The increase of multiple births seems to be related to a lower maternal age in case of procreative medical assistance. As a consequence, the rate of preterm births was also increased, resulting in 7.2% of all births. In another section a regular increase in the rate of cesarean sections, from 16.3% in 1999 to 17.6% was observed in 2001. Cesarean sections before labour are chiefly concerned. From 1999, each member of the AUDIPOG network is given access to the entire common database, on the Internet AUDIPOG site, in order to describe medical practices when faced with a particular clinical situation of interest. This access to the common database aids self-assessment of medical practices and quality improvement (http://audipog.inserm.fr).