Are the monthly spousal allocations of 50,0 Iraqi Dinars (approximately 170 Saudi Riyals) deducted and returned to the state after the wife is irrevocably divorced while pregnant, or are they to be given as charity?

The basic principle is that you are not entitled to this assistance after the third divorce, as you are not married. However, since your wife is pregnant and you are obligated to spend on her for the sake of the pregnancy, there is no harm in benefiting from this assistance and aid during the pregnancy. As for the money you received after the birth, you should donate it to public welfare.