Table 1.

Characteristics of the different sized networks.

Characteristics	Local and regional networks	Small national or nationwide networks	Large national networks	Very large networks or continental networks
Example	Reproductive medicine centre or clinic	Danish network (www.rigshospitalet.dk)	FertiPROTEKT (www.fertiprotekt.com)	Oncofertility Consortium (www.oncofertility.northwestern.edu)
Centralization of facilities (eg storage of gonadal tissue)	Yes	Yes, mostly one facility	Yes, mostly several facilities	Rather no
Continuing education	Bilateral exchange	Continuing education	National congresses	International congresses
Data collection in registers	Very possible	Quite possible, high data quality	Possible, lower data quality, but high data quantity	Possible to a limited extent
Political activities	Not as good	Good	Good	Not as good