I once tried eyeballing -- no serious statistical analysis -- national total fertility rates for a number of countries and then looking up when abortion became legal. I didn't see an obvious drop anywhere around legalization.
Legalized oral contraception did have a visible difference, though.
I'm not sure that re-banning abortion is actually gonna have much impact on fertility rates, though I'd be interested to see whether someone running an actual statistical analysis turns up anything.
A complicating factor might be enforcement level -- like, some countries might have had abortion be illegal at some point in time but also not enforced laws on it much. I did not attempt to account for that. Also might be a spillover effect from nearby countries with legalized abortion; people might just have traveled and gotten an abortion outside of their home region.