Organisations preparing to, or in the early stages of setting up, national or regional population-based Obstetric Survey Systems that have yet to meet the criteria to become an Obstetric Survey System Member.
Organisations undertaking national or regional population-based studies of serious, rare obstetric disorders using an alternative framework to an Obstetric Survey System.
Obstetric Survey System Members whose survey system has become inactive but wish to remain involved in INOSS.
Other international organisations working in the area of rare obstetric disorders, or related rare conditions, eg. the European organisation for Rare Diseases, the North American Organisation for Rare Diseases.
Other medical specialities using similar survey systems.