Praise be to Allah.
If it is medically proven that birth control pills are harmful to women, then it is not permissible to use them either before marriage or afterwards, on the basis of the rule that no harm should be done. This rule is based on the aayaat (interpretation of the meanings):
“And do not kill yourselves” [al-Nisa’ 4:29]
“and do not throw yourselves into destruction” [al-Baqarah 2:195]
Unless it is possible to produce pills that are free of harmful side effects, they should not be taken.
As for using any non-harmful means of contraception at the beginning of marriage, fearing that the marriage may not work out, there are a number of reservations about this, such as:
it may be a kind of pessimism, because you are expecting it to fail.
It may lead to an unhappy marital life and both spouses expecting bad of one another, because it is known that one of the most important purposes of marriage is to have children, and if this is delayed for a specific reason the relationship may cool off. If the husband finds out that this is what his wife is doing, it will spoil the relationship between them.
Pregnancy is one of the most important functions of women, which generates feelings of love and compassion towards her husband and children. If pregnancy is prevented the opposite feelings develop.
The fuqahaa’ (may Allaah have mercy on them) stipulated the condition for ‘azl (coitus interruptus) or other forms of contraception used by the woman, that it should only be done with the permission of the other spouse, because both of them have the right to have children. So it is not permissible for the wife to take birth control pills without her husband’s permission and consent.
The fear that the marriage may fail and the fact that there is a high divorce rate cannot be dealt with in this manner. The way to deal with it is to make the right choice of spouse and make sure that this is the right choice. The prospective husband should be allowed to see the prospective wife, because this is one of the ways of fostering love after marriage. Other means should also be used. We ask Allaah to guide us all. May Allaah bless our Prophet Muhammad.