I don't know if this would have stopped this particular instance but "Parenting" is one of three ad categories you can hide completely in your Facebook ad setti

I don't know if this would have stopped this particular instance but "Parenting" is one of three ad categories you can hide completely in your Facebook ad settings (the other two being Alcohol and Pets) so at least you have the option to be creeped out by other types of ads instead.