Is it permissible for a wife to use contraceptives without her husband's knowledge, given that he agrees to postpone pregnancy but they differ on the method of contraception?

It is permissible for a couple to temporarily postpone procreation for a benefit or to avert harm, such as the wife's exhaustion from successive pregnancies. This must be done after consultation and mutual agreement between them, provided that no harm results from it and that the method used is permissible.

Using contraceptives like pills and IUDs has health and psychological harms and may lead to menstrual cycle irregularities. Therefore, the husband has the right to prevent his wife from using them.

As for coitus interruptus (withdrawing before ejaculation), it is a safe method, but a man is not allowed to practice coitus interruptus with his wife without her permission, as she has a right to procreation and complete enjoyment. Among the safe methods are using condoms and knowing the ovulation days.

The wife is not allowed to use contraceptives that her husband does not approve of, because the harm will also affect him. The couple must be open and cooperate to achieve what is best for them and their children.