Ban not only abortion, but the sale of contraceptive devices as well.
The birth rate will increase.
Quite frankly, for Western whites, this will be the only way to restore the birth rate to pre-contraceptive era levels.
It's the reason the white race is slowly but certainly "un-breeding" itself out of existence.
On the other hand, we as a species could collectively think about simply maintaining a birth rate equal to our means.
Personally I don't see the need to push for massive increases in birth rate when the number of us here now are piss poor about managing the numbers we have. When we, white people included, don't have 'projects' or 'Appalachia', when Africa doesn't have famine etc, THEN we can worry about adding to the overall population figures.
Then there's the whole issue that most parents today suck. Now before some special snowflake screams "You're supporting abortion!" No, I'm not. I'm just saying we should seriously consider the consequences of increasing the world's numbers 'just cuz'.