I'm unfamiliar with what kind of changes they've made besides outlawing abortion please enlighten me.
They introduced 500+ program.
It promised 500 zloty (about 140 euro) per month from the government per child, mind you that the average salary in this country is like 2000 zloty (about 450 euro), and most low wage jobs like in shops are around 1400 zloty (about 250 euro), meaning borning some kids is usually a higher wage than working full time job.
However when they actually started the program it was only for the 2nd child and up, and after tax reduction you get about 400 zloty, still a lot of money.
So it does push mostly poor families to born a lot of kids.
However what nobody is told is that the Polish government doesn't have this money to spend, they loan it. the national debt of Poland is fast-rising, and no tax increases they can come up with is able to stop it, for instance recently they raised the gasoline tax so high that you pay more for gas in Poland than in Germany, mind you in Germany the income is about 3 times that of Poland.
In the Netherlands we have a saying for this; You get a cigar out of your own box.