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.
If there is any benefit in delaying pregnancy, then it is permissible, Allah willing. For that purpose, one should use the easiest and least harmful method. Yet, he should consult a doctor in this matter before implementing any procedure. Among the means for delaying a pregnancy are condoms, pills, injections and loops, etc. The rulings of each of these methods differ based on their effects and dangers.
Perhaps the safest way is planning sex life with one's wife, according to her fertility cycle.
For more benefit on this procedure, please refer to Fatwa 84240.
Allah knows best.