Up to what level family planning is allowed and what's best way?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Family planning is permissible only to gain benefits and avoid harms as per the Sharee'ah rulings. For instance, when a woman becomes too ill or gets exhausted due to consecutive pregnancies or to early pregnancy that could harm the fetus itself etc. But if the purpose of family planning is to decrease the human race, then it is prohibited. Because this practice contradicts the Will of Allah and the Sharee'ah rulings which urge Muslims to increase the progeny. This viewpoint is confirmed by the Islamic Fiqh Council (Majma' al-Fiqh al-Islami) and by the Permanent Committee of Islamic Research, Ifta, Call and Guidance. You may refer to a reliable experienced doctor to know the best way for family planning.

For more benefit on family planning, please refer to 99184, 97251, 84436, 82154, and 87155.

Allah knows best.