Is it permissible to stop giving 50 pounds monthly to the poor and needy, and to use the amount for a personal need, such as the wife's childbirth?

Spending in charitable causes is a great act of worship, encouraged by the Quran and Sunnah, as Allah Almighty says: "And spend out of that in which He has made you successors" (Quran 57:7), and "And whatever you spend of anything, He will compensate it; and He is the best of providers" (Quran 34:39). The Prophet, peace and blessings be upon him, said: "There is no day upon which the servants awaken but that two angels descend, and one of them says: 'O Allah, give compensation to one who spends!' And the other says: 'O Allah, give destruction to one who withholds!'" If the spending is voluntary and not obligatory, then it is permissible to withdraw from it absolutely, whether you need the money or not.