How is reproduction in Islam carried out?

Islam desires a large progeny and legislates marriage for the affectionate and fertile. However, it does not prohibit family planning when there is a need. The proof for this is that the Prophet (peace be upon him) did not forbid coitus interruptus (al-azl), which is a method of contraception. It is permissible to use contraceptive methods to achieve a benefit, such as protecting an infant and the mother's health. The Qur'an guided to an optimal period between births, which is thirty months. This is by way of guidance, not obligation, and the matter remains left to the family to decide what they see as beneficial for the infant and the mother.