All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Storing the frozen sperm or eggs for future use is a matter about which contemporary scholars have differed in opinion. Some of them said it is permissible and some said it is prohibited.
Their disagreement is based on the extent to which it can be ensured that the sperm or the egg will not be exposed to mixing, tampering or to the use of others, as this renders the person sinful or subjects his lineage to be mixed with others'.
If these prohibitions were avoided, then it would appear – and Allaah knows best – that it is permissible to use such techniques, provided the conditions clarified by the scholars about in-vitro fertilization are met. Please refer to Fataawa 82554 and 86041. Also, for more benefit, please refer to Fatwa 90358.
However, it is better not to resort to this except in cases of dire need. If there is no dire need, then it is better to avoid it in order to be on the safe side and to regard the differences of scholarly opinion.
Allaah Knows best.