A quote from Claus Vistesen at the Demography Matters blog, 3 November 2006

[L]et us look at a country in Eastern Europe with low fertility where pro-natalism actually seems to have worked at least given the initial evidence [Estonia]. [...] [W]ell done Estonia! However, what about other countries then and generally what would the initial outlook be for implementing pro-natalism as a general measure? [...]

Pro-natalist measures are essentially behavioural fiscal measures in terms of public budget policy and as such they have a negative effect on a country’s budget. [...] In order for pro-natalist measures to have a real effect and crucially to be fiscally sustainable they have to be enacted at a time where the society is actually capable of supporting the costs. As such pro-natalism cannot be enacted as a last-minute solution. [...]

Pro-natalism needs to be sustained [...]. A mere blip on the radar will not do and in short pro-natalism needs, to some extent at least, to be institutionalized as a structural mechanism.